From f9004dbfff8a3fbbd7e2a88c8a4327c7f2f8e5b2 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 01:04:47 +0000
Subject: [PATCH] add driver 5G
---
kernel/tools/lib/bpf/libbpf.c | 10745 +++++++++++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 9,633 insertions(+), 1,112 deletions(-)
diff --git a/kernel/tools/lib/bpf/libbpf.c b/kernel/tools/lib/bpf/libbpf.c
index 249fa8d..015ed82 100644
--- a/kernel/tools/lib/bpf/libbpf.c
+++ b/kernel/tools/lib/bpf/libbpf.c
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: LGPL-2.1
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
/*
* Common eBPF ELF object loading operations.
@@ -7,19 +7,7 @@
* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
* Copyright (C) 2015 Huawei Inc.
* Copyright (C) 2017 Nicira, Inc.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License (not later!)
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this program; if not, see <http://www.gnu.org/licenses>
+ * Copyright (C) 2019 Isovalent, Inc.
*/
#ifndef _GNU_SOURCE
@@ -30,29 +18,42 @@
#include <stdarg.h>
#include <libgen.h>
#include <inttypes.h>
+#include <limits.h>
#include <string.h>
#include <unistd.h>
+#include <endian.h>
#include <fcntl.h>
#include <errno.h>
-#include <perf-sys.h>
+#include <ctype.h>
#include <asm/unistd.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/bpf.h>
#include <linux/btf.h>
+#include <linux/filter.h>
#include <linux/list.h>
#include <linux/limits.h>
+#include <linux/perf_event.h>
+#include <linux/ring_buffer.h>
+#include <linux/version.h>
+#include <sys/epoll.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/vfs.h>
-#include <tools/libc_compat.h>
+#include <sys/utsname.h>
+#include <sys/resource.h>
#include <libelf.h>
#include <gelf.h>
+#include <zlib.h>
#include "libbpf.h"
#include "bpf.h"
#include "btf.h"
#include "str_error.h"
+#include "libbpf_internal.h"
+#include "hashmap.h"
#ifndef EM_BPF
#define EM_BPF 247
@@ -62,51 +63,78 @@
#define BPF_FS_MAGIC 0xcafe4a11
#endif
+#define BPF_INSN_SZ (sizeof(struct bpf_insn))
+
+/* vsprintf() in __base_pr() uses nonliteral format string. It may break
+ * compilation if user enables corresponding warning. Disable it explicitly.
+ */
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+
#define __printf(a, b) __attribute__((format(printf, a, b)))
-__printf(1, 2)
-static int __base_pr(const char *format, ...)
-{
- va_list args;
- int err;
+static struct bpf_map *bpf_object__add_map(struct bpf_object *obj);
+static const struct btf_type *
+skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
- va_start(args, format);
- err = vfprintf(stderr, format, args);
- va_end(args);
- return err;
+static int __base_pr(enum libbpf_print_level level, const char *format,
+ va_list args)
+{
+ if (level == LIBBPF_DEBUG)
+ return 0;
+
+ return vfprintf(stderr, format, args);
}
-static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
-static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
-static __printf(1, 2) libbpf_print_fn_t __pr_debug;
+static libbpf_print_fn_t __libbpf_pr = __base_pr;
-#define __pr(func, fmt, ...) \
-do { \
- if ((func)) \
- (func)("libbpf: " fmt, ##__VA_ARGS__); \
-} while (0)
-
-#define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
-#define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__)
-#define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__)
-
-void libbpf_set_print(libbpf_print_fn_t warn,
- libbpf_print_fn_t info,
- libbpf_print_fn_t debug)
+libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn)
{
- __pr_warning = warn;
- __pr_info = info;
- __pr_debug = debug;
+ libbpf_print_fn_t old_print_fn = __libbpf_pr;
+
+ __libbpf_pr = fn;
+ return old_print_fn;
+}
+
+__printf(2, 3)
+void libbpf_print(enum libbpf_print_level level, const char *format, ...)
+{
+ va_list args;
+
+ if (!__libbpf_pr)
+ return;
+
+ va_start(args, format);
+ __libbpf_pr(level, format, args);
+ va_end(args);
+}
+
+static void pr_perm_msg(int err)
+{
+ struct rlimit limit;
+ char buf[100];
+
+ if (err != -EPERM || geteuid() != 0)
+ return;
+
+ err = getrlimit(RLIMIT_MEMLOCK, &limit);
+ if (err)
+ return;
+
+ if (limit.rlim_cur == RLIM_INFINITY)
+ return;
+
+ if (limit.rlim_cur < 1024)
+ snprintf(buf, sizeof(buf), "%zu bytes", (size_t)limit.rlim_cur);
+ else if (limit.rlim_cur < 1024*1024)
+ snprintf(buf, sizeof(buf), "%.1f KiB", (double)limit.rlim_cur / 1024);
+ else
+ snprintf(buf, sizeof(buf), "%.1f MiB", (double)limit.rlim_cur / (1024*1024));
+
+ pr_warn("permission error while running as root; try raising 'ulimit -l'? current value: %s\n",
+ buf);
}
#define STRERR_BUFSIZE 128
-
-#define CHECK_ERR(action, err, out) do { \
- err = action; \
- if (err) \
- goto out; \
-} while(0)
-
/* Copied from tools/perf/util/util.h */
#ifndef zfree
@@ -122,38 +150,117 @@
___err; })
#endif
-#ifdef HAVE_LIBELF_MMAP_SUPPORT
-# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
-#else
-# define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
-#endif
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+ return (__u64) (unsigned long) ptr;
+}
+
+enum kern_feature_id {
+ /* v4.14: kernel support for program & map names. */
+ FEAT_PROG_NAME,
+ /* v5.2: kernel support for global data sections. */
+ FEAT_GLOBAL_DATA,
+ /* BTF support */
+ FEAT_BTF,
+ /* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
+ FEAT_BTF_FUNC,
+ /* BTF_KIND_VAR and BTF_KIND_DATASEC support */
+ FEAT_BTF_DATASEC,
+ /* BTF_FUNC_GLOBAL is supported */
+ FEAT_BTF_GLOBAL_FUNC,
+ /* BPF_F_MMAPABLE is supported for arrays */
+ FEAT_ARRAY_MMAP,
+ /* kernel support for expected_attach_type in BPF_PROG_LOAD */
+ FEAT_EXP_ATTACH_TYPE,
+ /* bpf_probe_read_{kernel,user}[_str] helpers */
+ FEAT_PROBE_READ_KERN,
+ /* BPF_PROG_BIND_MAP is supported */
+ FEAT_PROG_BIND_MAP,
+ __FEAT_CNT,
+};
+
+static bool kernel_supports(enum kern_feature_id feat_id);
+
+enum reloc_type {
+ RELO_LD64,
+ RELO_CALL,
+ RELO_DATA,
+ RELO_EXTERN,
+};
+
+struct reloc_desc {
+ enum reloc_type type;
+ int insn_idx;
+ int map_idx;
+ int sym_off;
+ bool processed;
+};
+
+struct bpf_sec_def;
+
+typedef struct bpf_link *(*attach_fn_t)(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+
+struct bpf_sec_def {
+ const char *sec;
+ size_t len;
+ enum bpf_prog_type prog_type;
+ enum bpf_attach_type expected_attach_type;
+ bool is_exp_attach_type_optional;
+ bool is_attachable;
+ bool is_attach_btf;
+ bool is_sleepable;
+ attach_fn_t attach_fn;
+};
/*
* bpf_prog should be a better name but it has been used in
* linux/filter.h.
*/
struct bpf_program {
- /* Index in elf obj file, for relocation use. */
- int idx;
- char *name;
- int prog_ifindex;
- char *section_name;
- struct bpf_insn *insns;
- size_t insns_cnt, main_prog_cnt;
- enum bpf_prog_type type;
+ const struct bpf_sec_def *sec_def;
+ char *sec_name;
+ size_t sec_idx;
+ /* this program's instruction offset (in number of instructions)
+ * within its containing ELF section
+ */
+ size_t sec_insn_off;
+ /* number of original instructions in ELF section belonging to this
+ * program, not taking into account subprogram instructions possible
+ * appended later during relocation
+ */
+ size_t sec_insn_cnt;
+ /* Offset (in number of instructions) of the start of instruction
+ * belonging to this BPF program within its containing main BPF
+ * program. For the entry-point (main) BPF program, this is always
+ * zero. For a sub-program, this gets reset before each of main BPF
+ * programs are processed and relocated and is used to determined
+ * whether sub-program was already appended to the main program, and
+ * if yes, at which instruction offset.
+ */
+ size_t sub_insn_off;
- struct reloc_desc {
- enum {
- RELO_LD64,
- RELO_CALL,
- } type;
- int insn_idx;
- union {
- int map_idx;
- int text_off;
- };
- } *reloc_desc;
+ char *name;
+ /* sec_name with / replaced by _; makes recursive pinning
+ * in bpf_object__pin_programs easier
+ */
+ char *pin_name;
+
+ /* instructions that belong to BPF program; insns[0] is located at
+ * sec_insn_off instruction within its ELF section in ELF file, so
+ * when mapping ELF file instruction index to the local instruction,
+ * one needs to subtract sec_insn_off; and vice versa.
+ */
+ struct bpf_insn *insns;
+ /* actual number of instruction in this BPF program's image; for
+ * entry-point BPF programs this includes the size of main program
+ * itself plus all the used sub-programs, appended at the end
+ */
+ size_t insns_cnt;
+
+ struct reloc_desc *reloc_desc;
int nr_reloc;
+ int log_level;
struct {
int nr;
@@ -165,34 +272,155 @@
void *priv;
bpf_program_clear_priv_t clear_priv;
+ bool load;
+ enum bpf_prog_type type;
enum bpf_attach_type expected_attach_type;
+ int prog_ifindex;
+ __u32 attach_btf_id;
+ __u32 attach_prog_fd;
+ void *func_info;
+ __u32 func_info_rec_size;
+ __u32 func_info_cnt;
+
+ void *line_info;
+ __u32 line_info_rec_size;
+ __u32 line_info_cnt;
+ __u32 prog_flags;
+};
+
+struct bpf_struct_ops {
+ const char *tname;
+ const struct btf_type *type;
+ struct bpf_program **progs;
+ __u32 *kern_func_off;
+ /* e.g. struct tcp_congestion_ops in bpf_prog's btf format */
+ void *data;
+ /* e.g. struct bpf_struct_ops_tcp_congestion_ops in
+ * btf_vmlinux's format.
+ * struct bpf_struct_ops_tcp_congestion_ops {
+ * [... some other kernel fields ...]
+ * struct tcp_congestion_ops data;
+ * }
+ * kern_vdata-size == sizeof(struct bpf_struct_ops_tcp_congestion_ops)
+ * bpf_map__init_kern_struct_ops() will populate the "kern_vdata"
+ * from "data".
+ */
+ void *kern_vdata;
+ __u32 type_id;
+};
+
+#define DATA_SEC ".data"
+#define BSS_SEC ".bss"
+#define RODATA_SEC ".rodata"
+#define KCONFIG_SEC ".kconfig"
+#define KSYMS_SEC ".ksyms"
+#define STRUCT_OPS_SEC ".struct_ops"
+
+enum libbpf_map_type {
+ LIBBPF_MAP_UNSPEC,
+ LIBBPF_MAP_DATA,
+ LIBBPF_MAP_BSS,
+ LIBBPF_MAP_RODATA,
+ LIBBPF_MAP_KCONFIG,
+};
+
+static const char * const libbpf_type_to_btf_name[] = {
+ [LIBBPF_MAP_DATA] = DATA_SEC,
+ [LIBBPF_MAP_BSS] = BSS_SEC,
+ [LIBBPF_MAP_RODATA] = RODATA_SEC,
+ [LIBBPF_MAP_KCONFIG] = KCONFIG_SEC,
};
struct bpf_map {
- int fd;
char *name;
- size_t offset;
+ int fd;
+ int sec_idx;
+ size_t sec_offset;
int map_ifindex;
+ int inner_map_fd;
struct bpf_map_def def;
+ __u32 numa_node;
+ __u32 btf_var_idx;
__u32 btf_key_type_id;
__u32 btf_value_type_id;
+ __u32 btf_vmlinux_value_type_id;
void *priv;
bpf_map_clear_priv_t clear_priv;
+ enum libbpf_map_type libbpf_type;
+ void *mmaped;
+ struct bpf_struct_ops *st_ops;
+ struct bpf_map *inner_map;
+ void **init_slots;
+ int init_slots_sz;
+ char *pin_path;
+ bool pinned;
+ bool reused;
+};
+
+enum extern_type {
+ EXT_UNKNOWN,
+ EXT_KCFG,
+ EXT_KSYM,
+};
+
+enum kcfg_type {
+ KCFG_UNKNOWN,
+ KCFG_CHAR,
+ KCFG_BOOL,
+ KCFG_INT,
+ KCFG_TRISTATE,
+ KCFG_CHAR_ARR,
+};
+
+struct extern_desc {
+ enum extern_type type;
+ int sym_idx;
+ int btf_id;
+ int sec_btf_id;
+ const char *name;
+ bool is_set;
+ bool is_weak;
+ union {
+ struct {
+ enum kcfg_type type;
+ int sz;
+ int align;
+ int data_off;
+ bool is_signed;
+ } kcfg;
+ struct {
+ unsigned long long addr;
+
+ /* target btf_id of the corresponding kernel var. */
+ int vmlinux_btf_id;
+
+ /* local btf_id of the ksym extern's type. */
+ __u32 type_id;
+ } ksym;
+ };
};
static LIST_HEAD(bpf_objects_list);
struct bpf_object {
+ char name[BPF_OBJ_NAME_LEN];
char license[64];
- u32 kern_version;
+ __u32 kern_version;
struct bpf_program *programs;
size_t nr_programs;
struct bpf_map *maps;
size_t nr_maps;
+ size_t maps_cap;
+
+ char *kconfig;
+ struct extern_desc *externs;
+ int nr_extern;
+ int kconfig_map_idx;
+ int rodata_map_idx;
bool loaded;
- bool has_pseudo_calls;
+ bool has_subcalls;
/*
* Information when doing elf related work. Only valid if fd
@@ -200,19 +428,31 @@
*/
struct {
int fd;
- void *obj_buf;
+ const void *obj_buf;
size_t obj_buf_sz;
Elf *elf;
GElf_Ehdr ehdr;
Elf_Data *symbols;
+ Elf_Data *data;
+ Elf_Data *rodata;
+ Elf_Data *bss;
+ Elf_Data *st_ops_data;
+ size_t shstrndx; /* section index for section name strings */
size_t strtabidx;
struct {
GElf_Shdr shdr;
Elf_Data *data;
- } *reloc;
- int nr_reloc;
+ } *reloc_sects;
+ int nr_reloc_sects;
int maps_shndx;
+ int btf_maps_shndx;
+ __u32 btf_maps_sec_btf_id;
int text_shndx;
+ int symbols_shndx;
+ int data_shndx;
+ int rodata_shndx;
+ int bss_shndx;
+ int st_ops_shndx;
} efile;
/*
* All loaded bpf_object is linked in a list, which is
@@ -222,6 +462,11 @@
struct list_head list;
struct btf *btf;
+ /* Parse and load BTF vmlinux if any of the programs in the object need
+ * it at load time.
+ */
+ struct btf *btf_vmlinux;
+ struct btf_ext *btf_ext;
void *priv;
bpf_object_clear_priv_t clear_priv;
@@ -230,7 +475,17 @@
};
#define obj_elf_valid(o) ((o)->efile.elf)
-static void bpf_program__unload(struct bpf_program *prog)
+static const char *elf_sym_str(const struct bpf_object *obj, size_t off);
+static const char *elf_sec_str(const struct bpf_object *obj, size_t off);
+static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx);
+static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name);
+static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr);
+static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn);
+static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn);
+static int elf_sym_by_sec_off(const struct bpf_object *obj, size_t sec_idx,
+ size_t off, __u32 sym_type, GElf_Sym *sym);
+
+void bpf_program__unload(struct bpf_program *prog)
{
int i;
@@ -245,12 +500,15 @@
for (i = 0; i < prog->instances.nr; i++)
zclose(prog->instances.fds[i]);
} else if (prog->instances.nr != -1) {
- pr_warning("Internal error: instances.nr is %d\n",
- prog->instances.nr);
+ pr_warn("Internal error: instances.nr is %d\n",
+ prog->instances.nr);
}
prog->instances.nr = -1;
zfree(&prog->instances.fds);
+
+ zfree(&prog->func_info);
+ zfree(&prog->line_info);
}
static void bpf_program__exit(struct bpf_program *prog)
@@ -266,158 +524,539 @@
bpf_program__unload(prog);
zfree(&prog->name);
- zfree(&prog->section_name);
+ zfree(&prog->sec_name);
+ zfree(&prog->pin_name);
zfree(&prog->insns);
zfree(&prog->reloc_desc);
prog->nr_reloc = 0;
prog->insns_cnt = 0;
- prog->idx = -1;
+ prog->sec_idx = -1;
+}
+
+static char *__bpf_program__pin_name(struct bpf_program *prog)
+{
+ char *name, *p;
+
+ name = p = strdup(prog->sec_name);
+ while ((p = strchr(p, '/')))
+ *p = '_';
+
+ return name;
+}
+
+static bool insn_is_subprog_call(const struct bpf_insn *insn)
+{
+ return BPF_CLASS(insn->code) == BPF_JMP &&
+ BPF_OP(insn->code) == BPF_CALL &&
+ BPF_SRC(insn->code) == BPF_K &&
+ insn->src_reg == BPF_PSEUDO_CALL &&
+ insn->dst_reg == 0 &&
+ insn->off == 0;
}
static int
-bpf_program__init(void *data, size_t size, char *section_name, int idx,
- struct bpf_program *prog)
+bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
+ const char *name, size_t sec_idx, const char *sec_name,
+ size_t sec_off, void *insn_data, size_t insn_data_sz)
{
- if (size < sizeof(struct bpf_insn)) {
- pr_warning("corrupted section '%s'\n", section_name);
+ if (insn_data_sz == 0 || insn_data_sz % BPF_INSN_SZ || sec_off % BPF_INSN_SZ) {
+ pr_warn("sec '%s': corrupted program '%s', offset %zu, size %zu\n",
+ sec_name, name, sec_off, insn_data_sz);
return -EINVAL;
}
- bzero(prog, sizeof(*prog));
+ memset(prog, 0, sizeof(*prog));
+ prog->obj = obj;
- prog->section_name = strdup(section_name);
- if (!prog->section_name) {
- pr_warning("failed to alloc name for prog under section(%d) %s\n",
- idx, section_name);
- goto errout;
- }
+ prog->sec_idx = sec_idx;
+ prog->sec_insn_off = sec_off / BPF_INSN_SZ;
+ prog->sec_insn_cnt = insn_data_sz / BPF_INSN_SZ;
+ /* insns_cnt can later be increased by appending used subprograms */
+ prog->insns_cnt = prog->sec_insn_cnt;
- prog->insns = malloc(size);
- if (!prog->insns) {
- pr_warning("failed to alloc insns for prog under section %s\n",
- section_name);
- goto errout;
- }
- prog->insns_cnt = size / sizeof(struct bpf_insn);
- memcpy(prog->insns, data,
- prog->insns_cnt * sizeof(struct bpf_insn));
- prog->idx = idx;
+ prog->type = BPF_PROG_TYPE_UNSPEC;
+ prog->load = true;
+
prog->instances.fds = NULL;
prog->instances.nr = -1;
- prog->type = BPF_PROG_TYPE_KPROBE;
+
+ prog->sec_name = strdup(sec_name);
+ if (!prog->sec_name)
+ goto errout;
+
+ prog->name = strdup(name);
+ if (!prog->name)
+ goto errout;
+
+ prog->pin_name = __bpf_program__pin_name(prog);
+ if (!prog->pin_name)
+ goto errout;
+
+ prog->insns = malloc(insn_data_sz);
+ if (!prog->insns)
+ goto errout;
+ memcpy(prog->insns, insn_data, insn_data_sz);
return 0;
errout:
+ pr_warn("sec '%s': failed to allocate memory for prog '%s'\n", sec_name, name);
bpf_program__exit(prog);
return -ENOMEM;
}
static int
-bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
- char *section_name, int idx)
+bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
+ const char *sec_name, int sec_idx)
{
- struct bpf_program prog, *progs;
+ struct bpf_program *prog, *progs;
+ void *data = sec_data->d_buf;
+ size_t sec_sz = sec_data->d_size, sec_off, prog_sz;
int nr_progs, err;
-
- err = bpf_program__init(data, size, section_name, idx, &prog);
- if (err)
- return err;
+ const char *name;
+ GElf_Sym sym;
progs = obj->programs;
nr_progs = obj->nr_programs;
+ sec_off = 0;
- progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
- if (!progs) {
- /*
- * In this case the original obj->programs
- * is still valid, so don't need special treat for
- * bpf_close_object().
- */
- pr_warning("failed to alloc a new program under section '%s'\n",
- section_name);
- bpf_program__exit(&prog);
- return -ENOMEM;
+ while (sec_off < sec_sz) {
+ if (elf_sym_by_sec_off(obj, sec_idx, sec_off, STT_FUNC, &sym)) {
+ pr_warn("sec '%s': failed to find program symbol at offset %zu\n",
+ sec_name, sec_off);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ prog_sz = sym.st_size;
+
+ name = elf_sym_str(obj, sym.st_name);
+ if (!name) {
+ pr_warn("sec '%s': failed to get symbol name for offset %zu\n",
+ sec_name, sec_off);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ if (sec_off + prog_sz > sec_sz) {
+ pr_warn("sec '%s': program at offset %zu crosses section boundary\n",
+ sec_name, sec_off);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ pr_debug("sec '%s': found program '%s' at insn offset %zu (%zu bytes), code size %zu insns (%zu bytes)\n",
+ sec_name, name, sec_off / BPF_INSN_SZ, sec_off, prog_sz / BPF_INSN_SZ, prog_sz);
+
+ progs = libbpf_reallocarray(progs, nr_progs + 1, sizeof(*progs));
+ if (!progs) {
+ /*
+ * In this case the original obj->programs
+ * is still valid, so don't need special treat for
+ * bpf_close_object().
+ */
+ pr_warn("sec '%s': failed to alloc memory for new program '%s'\n",
+ sec_name, name);
+ return -ENOMEM;
+ }
+ obj->programs = progs;
+
+ prog = &progs[nr_progs];
+
+ err = bpf_object__init_prog(obj, prog, name, sec_idx, sec_name,
+ sec_off, data + sec_off, prog_sz);
+ if (err)
+ return err;
+
+ nr_progs++;
+ obj->nr_programs = nr_progs;
+
+ sec_off += prog_sz;
}
- pr_debug("found program %s\n", prog.section_name);
- obj->programs = progs;
- obj->nr_programs = nr_progs + 1;
- prog.obj = obj;
- progs[nr_progs] = prog;
return 0;
}
-static int
-bpf_object__init_prog_names(struct bpf_object *obj)
+static __u32 get_kernel_version(void)
{
- Elf_Data *symbols = obj->efile.symbols;
- struct bpf_program *prog;
- size_t pi, si;
+ __u32 major, minor, patch;
+ struct utsname info;
- for (pi = 0; pi < obj->nr_programs; pi++) {
- const char *name = NULL;
+ uname(&info);
+ if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
+ return 0;
+ return KERNEL_VERSION(major, minor, patch);
+}
- prog = &obj->programs[pi];
+static const struct btf_member *
+find_member_by_offset(const struct btf_type *t, __u32 bit_offset)
+{
+ struct btf_member *m;
+ int i;
- for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name;
- si++) {
- GElf_Sym sym;
+ for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
+ if (btf_member_bit_offset(t, i) == bit_offset)
+ return m;
+ }
- if (!gelf_getsym(symbols, si, &sym))
- continue;
- if (sym.st_shndx != prog->idx)
- continue;
- if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL)
- continue;
+ return NULL;
+}
- name = elf_strptr(obj->efile.elf,
- obj->efile.strtabidx,
- sym.st_name);
- if (!name) {
- pr_warning("failed to get sym name string for prog %s\n",
- prog->section_name);
- return -LIBBPF_ERRNO__LIBELF;
- }
+static const struct btf_member *
+find_member_by_name(const struct btf *btf, const struct btf_type *t,
+ const char *name)
+{
+ struct btf_member *m;
+ int i;
+
+ for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
+ if (!strcmp(btf__name_by_offset(btf, m->name_off), name))
+ return m;
+ }
+
+ return NULL;
+}
+
+#define STRUCT_OPS_VALUE_PREFIX "bpf_struct_ops_"
+static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
+ const char *name, __u32 kind);
+
+static int
+find_struct_ops_kern_types(const struct btf *btf, const char *tname,
+ const struct btf_type **type, __u32 *type_id,
+ const struct btf_type **vtype, __u32 *vtype_id,
+ const struct btf_member **data_member)
+{
+ const struct btf_type *kern_type, *kern_vtype;
+ const struct btf_member *kern_data_member;
+ __s32 kern_vtype_id, kern_type_id;
+ __u32 i;
+
+ kern_type_id = btf__find_by_name_kind(btf, tname, BTF_KIND_STRUCT);
+ if (kern_type_id < 0) {
+ pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n",
+ tname);
+ return kern_type_id;
+ }
+ kern_type = btf__type_by_id(btf, kern_type_id);
+
+ /* Find the corresponding "map_value" type that will be used
+ * in map_update(BPF_MAP_TYPE_STRUCT_OPS). For example,
+ * find "struct bpf_struct_ops_tcp_congestion_ops" from the
+ * btf_vmlinux.
+ */
+ kern_vtype_id = find_btf_by_prefix_kind(btf, STRUCT_OPS_VALUE_PREFIX,
+ tname, BTF_KIND_STRUCT);
+ if (kern_vtype_id < 0) {
+ pr_warn("struct_ops init_kern: struct %s%s is not found in kernel BTF\n",
+ STRUCT_OPS_VALUE_PREFIX, tname);
+ return kern_vtype_id;
+ }
+ kern_vtype = btf__type_by_id(btf, kern_vtype_id);
+
+ /* Find "struct tcp_congestion_ops" from
+ * struct bpf_struct_ops_tcp_congestion_ops {
+ * [ ... ]
+ * struct tcp_congestion_ops data;
+ * }
+ */
+ kern_data_member = btf_members(kern_vtype);
+ for (i = 0; i < btf_vlen(kern_vtype); i++, kern_data_member++) {
+ if (kern_data_member->type == kern_type_id)
+ break;
+ }
+ if (i == btf_vlen(kern_vtype)) {
+ pr_warn("struct_ops init_kern: struct %s data is not found in struct %s%s\n",
+ tname, STRUCT_OPS_VALUE_PREFIX, tname);
+ return -EINVAL;
+ }
+
+ *type = kern_type;
+ *type_id = kern_type_id;
+ *vtype = kern_vtype;
+ *vtype_id = kern_vtype_id;
+ *data_member = kern_data_member;
+
+ return 0;
+}
+
+static bool bpf_map__is_struct_ops(const struct bpf_map *map)
+{
+ return map->def.type == BPF_MAP_TYPE_STRUCT_OPS;
+}
+
+/* Init the map's fields that depend on kern_btf */
+static int bpf_map__init_kern_struct_ops(struct bpf_map *map,
+ const struct btf *btf,
+ const struct btf *kern_btf)
+{
+ const struct btf_member *member, *kern_member, *kern_data_member;
+ const struct btf_type *type, *kern_type, *kern_vtype;
+ __u32 i, kern_type_id, kern_vtype_id, kern_data_off;
+ struct bpf_struct_ops *st_ops;
+ void *data, *kern_data;
+ const char *tname;
+ int err;
+
+ st_ops = map->st_ops;
+ type = st_ops->type;
+ tname = st_ops->tname;
+ err = find_struct_ops_kern_types(kern_btf, tname,
+ &kern_type, &kern_type_id,
+ &kern_vtype, &kern_vtype_id,
+ &kern_data_member);
+ if (err)
+ return err;
+
+ pr_debug("struct_ops init_kern %s: type_id:%u kern_type_id:%u kern_vtype_id:%u\n",
+ map->name, st_ops->type_id, kern_type_id, kern_vtype_id);
+
+ map->def.value_size = kern_vtype->size;
+ map->btf_vmlinux_value_type_id = kern_vtype_id;
+
+ st_ops->kern_vdata = calloc(1, kern_vtype->size);
+ if (!st_ops->kern_vdata)
+ return -ENOMEM;
+
+ data = st_ops->data;
+ kern_data_off = kern_data_member->offset / 8;
+ kern_data = st_ops->kern_vdata + kern_data_off;
+
+ member = btf_members(type);
+ for (i = 0; i < btf_vlen(type); i++, member++) {
+ const struct btf_type *mtype, *kern_mtype;
+ __u32 mtype_id, kern_mtype_id;
+ void *mdata, *kern_mdata;
+ __s64 msize, kern_msize;
+ __u32 moff, kern_moff;
+ __u32 kern_member_idx;
+ const char *mname;
+
+ mname = btf__name_by_offset(btf, member->name_off);
+ kern_member = find_member_by_name(kern_btf, kern_type, mname);
+ if (!kern_member) {
+ pr_warn("struct_ops init_kern %s: Cannot find member %s in kernel BTF\n",
+ map->name, mname);
+ return -ENOTSUP;
}
- if (!name && prog->idx == obj->efile.text_shndx)
- name = ".text";
+ kern_member_idx = kern_member - btf_members(kern_type);
+ if (btf_member_bitfield_size(type, i) ||
+ btf_member_bitfield_size(kern_type, kern_member_idx)) {
+ pr_warn("struct_ops init_kern %s: bitfield %s is not supported\n",
+ map->name, mname);
+ return -ENOTSUP;
+ }
- if (!name) {
- pr_warning("failed to find sym for prog %s\n",
- prog->section_name);
+ moff = member->offset / 8;
+ kern_moff = kern_member->offset / 8;
+
+ mdata = data + moff;
+ kern_mdata = kern_data + kern_moff;
+
+ mtype = skip_mods_and_typedefs(btf, member->type, &mtype_id);
+ kern_mtype = skip_mods_and_typedefs(kern_btf, kern_member->type,
+ &kern_mtype_id);
+ if (BTF_INFO_KIND(mtype->info) !=
+ BTF_INFO_KIND(kern_mtype->info)) {
+ pr_warn("struct_ops init_kern %s: Unmatched member type %s %u != %u(kernel)\n",
+ map->name, mname, BTF_INFO_KIND(mtype->info),
+ BTF_INFO_KIND(kern_mtype->info));
+ return -ENOTSUP;
+ }
+
+ if (btf_is_ptr(mtype)) {
+ struct bpf_program *prog;
+
+ prog = st_ops->progs[i];
+ if (!prog)
+ continue;
+
+ kern_mtype = skip_mods_and_typedefs(kern_btf,
+ kern_mtype->type,
+ &kern_mtype_id);
+
+ /* mtype->type must be a func_proto which was
+ * guaranteed in bpf_object__collect_st_ops_relos(),
+ * so only check kern_mtype for func_proto here.
+ */
+ if (!btf_is_func_proto(kern_mtype)) {
+ pr_warn("struct_ops init_kern %s: kernel member %s is not a func ptr\n",
+ map->name, mname);
+ return -ENOTSUP;
+ }
+
+ prog->attach_btf_id = kern_type_id;
+ prog->expected_attach_type = kern_member_idx;
+
+ st_ops->kern_func_off[i] = kern_data_off + kern_moff;
+
+ pr_debug("struct_ops init_kern %s: func ptr %s is set to prog %s from data(+%u) to kern_data(+%u)\n",
+ map->name, mname, prog->name, moff,
+ kern_moff);
+
+ continue;
+ }
+
+ msize = btf__resolve_size(btf, mtype_id);
+ kern_msize = btf__resolve_size(kern_btf, kern_mtype_id);
+ if (msize < 0 || kern_msize < 0 || msize != kern_msize) {
+ pr_warn("struct_ops init_kern %s: Error in size of member %s: %zd != %zd(kernel)\n",
+ map->name, mname, (ssize_t)msize,
+ (ssize_t)kern_msize);
+ return -ENOTSUP;
+ }
+
+ pr_debug("struct_ops init_kern %s: copy %s %u bytes from data(+%u) to kern_data(+%u)\n",
+ map->name, mname, (unsigned int)msize,
+ moff, kern_moff);
+ memcpy(kern_mdata, mdata, msize);
+ }
+
+ return 0;
+}
+
+static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj)
+{
+ struct bpf_map *map;
+ size_t i;
+ int err;
+
+ for (i = 0; i < obj->nr_maps; i++) {
+ map = &obj->maps[i];
+
+ if (!bpf_map__is_struct_ops(map))
+ continue;
+
+ err = bpf_map__init_kern_struct_ops(map, obj->btf,
+ obj->btf_vmlinux);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int bpf_object__init_struct_ops_maps(struct bpf_object *obj)
+{
+ const struct btf_type *type, *datasec;
+ const struct btf_var_secinfo *vsi;
+ struct bpf_struct_ops *st_ops;
+ const char *tname, *var_name;
+ __s32 type_id, datasec_id;
+ const struct btf *btf;
+ struct bpf_map *map;
+ __u32 i;
+
+ if (obj->efile.st_ops_shndx == -1)
+ return 0;
+
+ btf = obj->btf;
+ datasec_id = btf__find_by_name_kind(btf, STRUCT_OPS_SEC,
+ BTF_KIND_DATASEC);
+ if (datasec_id < 0) {
+ pr_warn("struct_ops init: DATASEC %s not found\n",
+ STRUCT_OPS_SEC);
+ return -EINVAL;
+ }
+
+ datasec = btf__type_by_id(btf, datasec_id);
+ vsi = btf_var_secinfos(datasec);
+ for (i = 0; i < btf_vlen(datasec); i++, vsi++) {
+ type = btf__type_by_id(obj->btf, vsi->type);
+ var_name = btf__name_by_offset(obj->btf, type->name_off);
+
+ type_id = btf__resolve_type(obj->btf, vsi->type);
+ if (type_id < 0) {
+ pr_warn("struct_ops init: Cannot resolve var type_id %u in DATASEC %s\n",
+ vsi->type, STRUCT_OPS_SEC);
return -EINVAL;
}
- prog->name = strdup(name);
- if (!prog->name) {
- pr_warning("failed to allocate memory for prog sym %s\n",
- name);
- return -ENOMEM;
+ type = btf__type_by_id(obj->btf, type_id);
+ tname = btf__name_by_offset(obj->btf, type->name_off);
+ if (!tname[0]) {
+ pr_warn("struct_ops init: anonymous type is not supported\n");
+ return -ENOTSUP;
}
+ if (!btf_is_struct(type)) {
+ pr_warn("struct_ops init: %s is not a struct\n", tname);
+ return -EINVAL;
+ }
+
+ map = bpf_object__add_map(obj);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ map->sec_idx = obj->efile.st_ops_shndx;
+ map->sec_offset = vsi->offset;
+ map->name = strdup(var_name);
+ if (!map->name)
+ return -ENOMEM;
+
+ map->def.type = BPF_MAP_TYPE_STRUCT_OPS;
+ map->def.key_size = sizeof(int);
+ map->def.value_size = type->size;
+ map->def.max_entries = 1;
+
+ map->st_ops = calloc(1, sizeof(*map->st_ops));
+ if (!map->st_ops)
+ return -ENOMEM;
+ st_ops = map->st_ops;
+ st_ops->data = malloc(type->size);
+ st_ops->progs = calloc(btf_vlen(type), sizeof(*st_ops->progs));
+ st_ops->kern_func_off = malloc(btf_vlen(type) *
+ sizeof(*st_ops->kern_func_off));
+ if (!st_ops->data || !st_ops->progs || !st_ops->kern_func_off)
+ return -ENOMEM;
+
+ if (vsi->offset + type->size > obj->efile.st_ops_data->d_size) {
+ pr_warn("struct_ops init: var %s is beyond the end of DATASEC %s\n",
+ var_name, STRUCT_OPS_SEC);
+ return -EINVAL;
+ }
+
+ memcpy(st_ops->data,
+ obj->efile.st_ops_data->d_buf + vsi->offset,
+ type->size);
+ st_ops->tname = tname;
+ st_ops->type = type;
+ st_ops->type_id = type_id;
+
+ pr_debug("struct_ops init: struct %s(type_id=%u) %s found at offset %u\n",
+ tname, type_id, var_name, vsi->offset);
}
return 0;
}
static struct bpf_object *bpf_object__new(const char *path,
- void *obj_buf,
- size_t obj_buf_sz)
+ const void *obj_buf,
+ size_t obj_buf_sz,
+ const char *obj_name)
{
struct bpf_object *obj;
+ char *end;
obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
if (!obj) {
- pr_warning("alloc memory failed for %s\n", path);
+ pr_warn("alloc memory failed for %s\n", path);
return ERR_PTR(-ENOMEM);
}
strcpy(obj->path, path);
- obj->efile.fd = -1;
+ if (obj_name) {
+ strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
+ obj->name[sizeof(obj->name) - 1] = 0;
+ } else {
+ /* Using basename() GNU version which doesn't modify arg. */
+ strncpy(obj->name, basename((void *)path),
+ sizeof(obj->name) - 1);
+ end = strchr(obj->name, '.');
+ if (end)
+ *end = 0;
+ }
+ obj->efile.fd = -1;
/*
- * Caller of this function should also calls
+ * Caller of this function should also call
* bpf_object__elf_finish() after data collection to return
* obj_buf to user. If not, we should duplicate the buffer to
* avoid user freeing them before elf finish.
@@ -425,7 +1064,15 @@
obj->efile.obj_buf = obj_buf;
obj->efile.obj_buf_sz = obj_buf_sz;
obj->efile.maps_shndx = -1;
+ obj->efile.btf_maps_shndx = -1;
+ obj->efile.data_shndx = -1;
+ obj->efile.rodata_shndx = -1;
+ obj->efile.bss_shndx = -1;
+ obj->efile.st_ops_shndx = -1;
+ obj->kconfig_map_idx = -1;
+ obj->rodata_map_idx = -1;
+ obj->kern_version = get_kernel_version();
obj->loaded = false;
INIT_LIST_HEAD(&obj->list);
@@ -443,13 +1090,22 @@
obj->efile.elf = NULL;
}
obj->efile.symbols = NULL;
+ obj->efile.data = NULL;
+ obj->efile.rodata = NULL;
+ obj->efile.bss = NULL;
+ obj->efile.st_ops_data = NULL;
- zfree(&obj->efile.reloc);
- obj->efile.nr_reloc = 0;
+ zfree(&obj->efile.reloc_sects);
+ obj->efile.nr_reloc_sects = 0;
zclose(obj->efile.fd);
obj->efile.obj_buf = NULL;
obj->efile.obj_buf_sz = 0;
}
+
+/* if libelf is old and doesn't support mmap(), fall back to read() */
+#ifndef ELF_C_READ_MMAP
+#define ELF_C_READ_MMAP ELF_C_READ
+#endif
static int bpf_object__elf_init(struct bpf_object *obj)
{
@@ -457,7 +1113,7 @@
GElf_Ehdr *ep;
if (obj_elf_valid(obj)) {
- pr_warning("elf init: internal error\n");
+ pr_warn("elf: init internal error\n");
return -LIBBPF_ERRNO__LIBELF;
}
@@ -466,42 +1122,54 @@
* obj_buf should have been validated by
* bpf_object__open_buffer().
*/
- obj->efile.elf = elf_memory(obj->efile.obj_buf,
+ obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
obj->efile.obj_buf_sz);
} else {
obj->efile.fd = open(obj->path, O_RDONLY);
if (obj->efile.fd < 0) {
- char errmsg[STRERR_BUFSIZE];
- char *cp = str_error(errno, errmsg, sizeof(errmsg));
+ char errmsg[STRERR_BUFSIZE], *cp;
- pr_warning("failed to open %s: %s\n", obj->path, cp);
- return -errno;
+ err = -errno;
+ cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+ pr_warn("elf: failed to open %s: %s\n", obj->path, cp);
+ return err;
}
- obj->efile.elf = elf_begin(obj->efile.fd,
- LIBBPF_ELF_C_READ_MMAP,
- NULL);
+ obj->efile.elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL);
}
if (!obj->efile.elf) {
- pr_warning("failed to open %s as ELF file\n",
- obj->path);
+ pr_warn("elf: failed to open %s as ELF file: %s\n", obj->path, elf_errmsg(-1));
err = -LIBBPF_ERRNO__LIBELF;
goto errout;
}
if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
- pr_warning("failed to get EHDR from %s\n",
- obj->path);
+ pr_warn("elf: failed to get ELF header from %s: %s\n", obj->path, elf_errmsg(-1));
err = -LIBBPF_ERRNO__FORMAT;
goto errout;
}
ep = &obj->efile.ehdr;
+ if (elf_getshdrstrndx(obj->efile.elf, &obj->efile.shstrndx)) {
+ pr_warn("elf: failed to get section names section index for %s: %s\n",
+ obj->path, elf_errmsg(-1));
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto errout;
+ }
+
+ /* Elf is corrupted/truncated, avoid calling elf_strptr. */
+ if (!elf_rawdata(elf_getscn(obj->efile.elf, obj->efile.shstrndx), NULL)) {
+ pr_warn("elf: failed to get section names strings from %s: %s\n",
+ obj->path, elf_errmsg(-1));
+ err = -LIBBPF_ERRNO__FORMAT;
+ goto errout;
+ }
+
/* Old LLVM set e_machine to EM_NONE */
- if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) {
- pr_warning("%s is not an eBPF object file\n",
- obj->path);
+ if (ep->e_type != ET_REL ||
+ (ep->e_machine && ep->e_machine != EM_BPF)) {
+ pr_warn("elf: %s is not a valid eBPF object file\n", obj->path);
err = -LIBBPF_ERRNO__FORMAT;
goto errout;
}
@@ -512,88 +1180,589 @@
return err;
}
-static int
-bpf_object__check_endianness(struct bpf_object *obj)
+static int bpf_object__check_endianness(struct bpf_object *obj)
{
- static unsigned int const endian = 1;
-
- switch (obj->efile.ehdr.e_ident[EI_DATA]) {
- case ELFDATA2LSB:
- /* We are big endian, BPF obj is little endian. */
- if (*(unsigned char const *)&endian != 1)
- goto mismatch;
- break;
-
- case ELFDATA2MSB:
- /* We are little endian, BPF obj is big endian. */
- if (*(unsigned char const *)&endian != 0)
- goto mismatch;
- break;
- default:
- return -LIBBPF_ERRNO__ENDIAN;
- }
-
- return 0;
-
-mismatch:
- pr_warning("Error: endianness mismatch.\n");
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
+ return 0;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+ if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
+ return 0;
+#else
+# error "Unrecognized __BYTE_ORDER__"
+#endif
+ pr_warn("elf: endianness mismatch in %s.\n", obj->path);
return -LIBBPF_ERRNO__ENDIAN;
}
static int
-bpf_object__init_license(struct bpf_object *obj,
- void *data, size_t size)
+bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
{
- memcpy(obj->license, data,
- min(size, sizeof(obj->license) - 1));
+ memcpy(obj->license, data, min(size, sizeof(obj->license) - 1));
pr_debug("license of %s is %s\n", obj->path, obj->license);
return 0;
}
static int
-bpf_object__init_kversion(struct bpf_object *obj,
- void *data, size_t size)
+bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size)
{
- u32 kver;
+ __u32 kver;
if (size != sizeof(kver)) {
- pr_warning("invalid kver section in %s\n", obj->path);
+ pr_warn("invalid kver section in %s\n", obj->path);
return -LIBBPF_ERRNO__FORMAT;
}
memcpy(&kver, data, sizeof(kver));
obj->kern_version = kver;
- pr_debug("kernel version of %s is %x\n", obj->path,
- obj->kern_version);
+ pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version);
return 0;
}
-static int compare_bpf_map(const void *_a, const void *_b)
+static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
{
- const struct bpf_map *a = _a;
- const struct bpf_map *b = _b;
+ if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
+ type == BPF_MAP_TYPE_HASH_OF_MAPS)
+ return true;
+ return false;
+}
- return a->offset - b->offset;
+int bpf_object__section_size(const struct bpf_object *obj, const char *name,
+ __u32 *size)
+{
+ int ret = -ENOENT;
+
+ *size = 0;
+ if (!name) {
+ return -EINVAL;
+ } else if (!strcmp(name, DATA_SEC)) {
+ if (obj->efile.data)
+ *size = obj->efile.data->d_size;
+ } else if (!strcmp(name, BSS_SEC)) {
+ if (obj->efile.bss)
+ *size = obj->efile.bss->d_size;
+ } else if (!strcmp(name, RODATA_SEC)) {
+ if (obj->efile.rodata)
+ *size = obj->efile.rodata->d_size;
+ } else if (!strcmp(name, STRUCT_OPS_SEC)) {
+ if (obj->efile.st_ops_data)
+ *size = obj->efile.st_ops_data->d_size;
+ } else {
+ Elf_Scn *scn = elf_sec_by_name(obj, name);
+ Elf_Data *data = elf_sec_data(obj, scn);
+
+ if (data) {
+ ret = 0; /* found it */
+ *size = data->d_size;
+ }
+ }
+
+ return *size ? 0 : ret;
+}
+
+int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
+ __u32 *off)
+{
+ Elf_Data *symbols = obj->efile.symbols;
+ const char *sname;
+ size_t si;
+
+ if (!name || !off)
+ return -EINVAL;
+
+ for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
+ GElf_Sym sym;
+
+ if (!gelf_getsym(symbols, si, &sym))
+ continue;
+ if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
+ GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
+ continue;
+
+ sname = elf_sym_str(obj, sym.st_name);
+ if (!sname) {
+ pr_warn("failed to get sym name string for var %s\n",
+ name);
+ return -EIO;
+ }
+ if (strcmp(name, sname) == 0) {
+ *off = sym.st_value;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
+{
+ struct bpf_map *new_maps;
+ size_t new_cap;
+ int i;
+
+ if (obj->nr_maps < obj->maps_cap)
+ return &obj->maps[obj->nr_maps++];
+
+ new_cap = max((size_t)4, obj->maps_cap * 3 / 2);
+ new_maps = libbpf_reallocarray(obj->maps, new_cap, sizeof(*obj->maps));
+ if (!new_maps) {
+ pr_warn("alloc maps for object failed\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ obj->maps_cap = new_cap;
+ obj->maps = new_maps;
+
+ /* zero out new maps */
+ memset(obj->maps + obj->nr_maps, 0,
+ (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps));
+ /*
+ * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin)
+ * when failure (zclose won't close negative fd)).
+ */
+ for (i = obj->nr_maps; i < obj->maps_cap; i++) {
+ obj->maps[i].fd = -1;
+ obj->maps[i].inner_map_fd = -1;
+ }
+
+ return &obj->maps[obj->nr_maps++];
+}
+
+static size_t bpf_map_mmap_sz(const struct bpf_map *map)
+{
+ long page_sz = sysconf(_SC_PAGE_SIZE);
+ size_t map_sz;
+
+ map_sz = (size_t)roundup(map->def.value_size, 8) * map->def.max_entries;
+ map_sz = roundup(map_sz, page_sz);
+ return map_sz;
+}
+
+static char *internal_map_name(struct bpf_object *obj,
+ enum libbpf_map_type type)
+{
+ char map_name[BPF_OBJ_NAME_LEN], *p;
+ const char *sfx = libbpf_type_to_btf_name[type];
+ int sfx_len = max((size_t)7, strlen(sfx));
+ int pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1,
+ strlen(obj->name));
+
+ snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
+ sfx_len, libbpf_type_to_btf_name[type]);
+
+ /* sanitise map name to characters allowed by kernel */
+ for (p = map_name; *p && p < map_name + sizeof(map_name); p++)
+ if (!isalnum(*p) && *p != '_' && *p != '.')
+ *p = '_';
+
+ return strdup(map_name);
}
static int
-bpf_object__init_maps(struct bpf_object *obj)
+bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
+ int sec_idx, void *data, size_t data_sz)
{
- int i, map_idx, map_def_sz, nr_maps = 0;
- Elf_Scn *scn;
- Elf_Data *data;
+ struct bpf_map_def *def;
+ struct bpf_map *map;
+ int err;
+
+ map = bpf_object__add_map(obj);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ map->libbpf_type = type;
+ map->sec_idx = sec_idx;
+ map->sec_offset = 0;
+ map->name = internal_map_name(obj, type);
+ if (!map->name) {
+ pr_warn("failed to alloc map name\n");
+ return -ENOMEM;
+ }
+
+ def = &map->def;
+ def->type = BPF_MAP_TYPE_ARRAY;
+ def->key_size = sizeof(int);
+ def->value_size = data_sz;
+ def->max_entries = 1;
+ def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG
+ ? BPF_F_RDONLY_PROG : 0;
+ def->map_flags |= BPF_F_MMAPABLE;
+
+ pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
+ map->name, map->sec_idx, map->sec_offset, def->map_flags);
+
+ map->mmaped = mmap(NULL, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ if (map->mmaped == MAP_FAILED) {
+ err = -errno;
+ map->mmaped = NULL;
+ pr_warn("failed to alloc map '%s' content buffer: %d\n",
+ map->name, err);
+ zfree(&map->name);
+ return err;
+ }
+
+ if (data)
+ memcpy(map->mmaped, data, data_sz);
+
+ pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name);
+ return 0;
+}
+
+static int bpf_object__init_global_data_maps(struct bpf_object *obj)
+{
+ int err;
+
+ /*
+ * Populate obj->maps with libbpf internal maps.
+ */
+ if (obj->efile.data_shndx >= 0) {
+ err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
+ obj->efile.data_shndx,
+ obj->efile.data->d_buf,
+ obj->efile.data->d_size);
+ if (err)
+ return err;
+ }
+ if (obj->efile.rodata_shndx >= 0) {
+ err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
+ obj->efile.rodata_shndx,
+ obj->efile.rodata->d_buf,
+ obj->efile.rodata->d_size);
+ if (err)
+ return err;
+
+ obj->rodata_map_idx = obj->nr_maps - 1;
+ }
+ if (obj->efile.bss_shndx >= 0) {
+ err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
+ obj->efile.bss_shndx,
+ NULL,
+ obj->efile.bss->d_size);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+
+static struct extern_desc *find_extern_by_name(const struct bpf_object *obj,
+ const void *name)
+{
+ int i;
+
+ for (i = 0; i < obj->nr_extern; i++) {
+ if (strcmp(obj->externs[i].name, name) == 0)
+ return &obj->externs[i];
+ }
+ return NULL;
+}
+
+static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val,
+ char value)
+{
+ switch (ext->kcfg.type) {
+ case KCFG_BOOL:
+ if (value == 'm') {
+ pr_warn("extern (kcfg) %s=%c should be tristate or char\n",
+ ext->name, value);
+ return -EINVAL;
+ }
+ *(bool *)ext_val = value == 'y' ? true : false;
+ break;
+ case KCFG_TRISTATE:
+ if (value == 'y')
+ *(enum libbpf_tristate *)ext_val = TRI_YES;
+ else if (value == 'm')
+ *(enum libbpf_tristate *)ext_val = TRI_MODULE;
+ else /* value == 'n' */
+ *(enum libbpf_tristate *)ext_val = TRI_NO;
+ break;
+ case KCFG_CHAR:
+ *(char *)ext_val = value;
+ break;
+ case KCFG_UNKNOWN:
+ case KCFG_INT:
+ case KCFG_CHAR_ARR:
+ default:
+ pr_warn("extern (kcfg) %s=%c should be bool, tristate, or char\n",
+ ext->name, value);
+ return -EINVAL;
+ }
+ ext->is_set = true;
+ return 0;
+}
+
+static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val,
+ const char *value)
+{
+ size_t len;
+
+ if (ext->kcfg.type != KCFG_CHAR_ARR) {
+ pr_warn("extern (kcfg) %s=%s should be char array\n", ext->name, value);
+ return -EINVAL;
+ }
+
+ len = strlen(value);
+ if (value[len - 1] != '"') {
+ pr_warn("extern (kcfg) '%s': invalid string config '%s'\n",
+ ext->name, value);
+ return -EINVAL;
+ }
+
+ /* strip quotes */
+ len -= 2;
+ if (len >= ext->kcfg.sz) {
+ pr_warn("extern (kcfg) '%s': long string config %s of (%zu bytes) truncated to %d bytes\n",
+ ext->name, value, len, ext->kcfg.sz - 1);
+ len = ext->kcfg.sz - 1;
+ }
+ memcpy(ext_val, value + 1, len);
+ ext_val[len] = '\0';
+ ext->is_set = true;
+ return 0;
+}
+
+static int parse_u64(const char *value, __u64 *res)
+{
+ char *value_end;
+ int err;
+
+ errno = 0;
+ *res = strtoull(value, &value_end, 0);
+ if (errno) {
+ err = -errno;
+ pr_warn("failed to parse '%s' as integer: %d\n", value, err);
+ return err;
+ }
+ if (*value_end) {
+ pr_warn("failed to parse '%s' as integer completely\n", value);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v)
+{
+ int bit_sz = ext->kcfg.sz * 8;
+
+ if (ext->kcfg.sz == 8)
+ return true;
+
+ /* Validate that value stored in u64 fits in integer of `ext->sz`
+ * bytes size without any loss of information. If the target integer
+ * is signed, we rely on the following limits of integer type of
+ * Y bits and subsequent transformation:
+ *
+ * -2^(Y-1) <= X <= 2^(Y-1) - 1
+ * 0 <= X + 2^(Y-1) <= 2^Y - 1
+ * 0 <= X + 2^(Y-1) < 2^Y
+ *
+ * For unsigned target integer, check that all the (64 - Y) bits are
+ * zero.
+ */
+ if (ext->kcfg.is_signed)
+ return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz);
+ else
+ return (v >> bit_sz) == 0;
+}
+
+static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val,
+ __u64 value)
+{
+ if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) {
+ pr_warn("extern (kcfg) %s=%llu should be integer\n",
+ ext->name, (unsigned long long)value);
+ return -EINVAL;
+ }
+ if (!is_kcfg_value_in_range(ext, value)) {
+ pr_warn("extern (kcfg) %s=%llu value doesn't fit in %d bytes\n",
+ ext->name, (unsigned long long)value, ext->kcfg.sz);
+ return -ERANGE;
+ }
+ switch (ext->kcfg.sz) {
+ case 1: *(__u8 *)ext_val = value; break;
+ case 2: *(__u16 *)ext_val = value; break;
+ case 4: *(__u32 *)ext_val = value; break;
+ case 8: *(__u64 *)ext_val = value; break;
+ default:
+ return -EINVAL;
+ }
+ ext->is_set = true;
+ return 0;
+}
+
+static int bpf_object__process_kconfig_line(struct bpf_object *obj,
+ char *buf, void *data)
+{
+ struct extern_desc *ext;
+ char *sep, *value;
+ int len, err = 0;
+ void *ext_val;
+ __u64 num;
+
+ if (strncmp(buf, "CONFIG_", 7))
+ return 0;
+
+ sep = strchr(buf, '=');
+ if (!sep) {
+ pr_warn("failed to parse '%s': no separator\n", buf);
+ return -EINVAL;
+ }
+
+ /* Trim ending '\n' */
+ len = strlen(buf);
+ if (buf[len - 1] == '\n')
+ buf[len - 1] = '\0';
+ /* Split on '=' and ensure that a value is present. */
+ *sep = '\0';
+ if (!sep[1]) {
+ *sep = '=';
+ pr_warn("failed to parse '%s': no value\n", buf);
+ return -EINVAL;
+ }
+
+ ext = find_extern_by_name(obj, buf);
+ if (!ext || ext->is_set)
+ return 0;
+
+ ext_val = data + ext->kcfg.data_off;
+ value = sep + 1;
+
+ switch (*value) {
+ case 'y': case 'n': case 'm':
+ err = set_kcfg_value_tri(ext, ext_val, *value);
+ break;
+ case '"':
+ err = set_kcfg_value_str(ext, ext_val, value);
+ break;
+ default:
+ /* assume integer */
+ err = parse_u64(value, &num);
+ if (err) {
+ pr_warn("extern (kcfg) %s=%s should be integer\n",
+ ext->name, value);
+ return err;
+ }
+ err = set_kcfg_value_num(ext, ext_val, num);
+ break;
+ }
+ if (err)
+ return err;
+ pr_debug("extern (kcfg) %s=%s\n", ext->name, value);
+ return 0;
+}
+
+static int bpf_object__read_kconfig_file(struct bpf_object *obj, void *data)
+{
+ char buf[PATH_MAX];
+ struct utsname uts;
+ int len, err = 0;
+ gzFile file;
+
+ uname(&uts);
+ len = snprintf(buf, PATH_MAX, "/boot/config-%s", uts.release);
+ if (len < 0)
+ return -EINVAL;
+ else if (len >= PATH_MAX)
+ return -ENAMETOOLONG;
+
+ /* gzopen also accepts uncompressed files. */
+ file = gzopen(buf, "r");
+ if (!file)
+ file = gzopen("/proc/config.gz", "r");
+
+ if (!file) {
+ pr_warn("failed to open system Kconfig\n");
+ return -ENOENT;
+ }
+
+ while (gzgets(file, buf, sizeof(buf))) {
+ err = bpf_object__process_kconfig_line(obj, buf, data);
+ if (err) {
+ pr_warn("error parsing system Kconfig line '%s': %d\n",
+ buf, err);
+ goto out;
+ }
+ }
+
+out:
+ gzclose(file);
+ return err;
+}
+
+static int bpf_object__read_kconfig_mem(struct bpf_object *obj,
+ const char *config, void *data)
+{
+ char buf[PATH_MAX];
+ int err = 0;
+ FILE *file;
+
+ file = fmemopen((void *)config, strlen(config), "r");
+ if (!file) {
+ err = -errno;
+ pr_warn("failed to open in-memory Kconfig: %d\n", err);
+ return err;
+ }
+
+ while (fgets(buf, sizeof(buf), file)) {
+ err = bpf_object__process_kconfig_line(obj, buf, data);
+ if (err) {
+ pr_warn("error parsing in-memory Kconfig line '%s': %d\n",
+ buf, err);
+ break;
+ }
+ }
+
+ fclose(file);
+ return err;
+}
+
+static int bpf_object__init_kconfig_map(struct bpf_object *obj)
+{
+ struct extern_desc *last_ext = NULL, *ext;
+ size_t map_sz;
+ int i, err;
+
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+ if (ext->type == EXT_KCFG)
+ last_ext = ext;
+ }
+
+ if (!last_ext)
+ return 0;
+
+ map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz;
+ err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG,
+ obj->efile.symbols_shndx,
+ NULL, map_sz);
+ if (err)
+ return err;
+
+ obj->kconfig_map_idx = obj->nr_maps - 1;
+
+ return 0;
+}
+
+static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
+{
Elf_Data *symbols = obj->efile.symbols;
+ int i, map_def_sz = 0, nr_maps = 0, nr_syms;
+ Elf_Data *data = NULL;
+ Elf_Scn *scn;
if (obj->efile.maps_shndx < 0)
- return -EINVAL;
+ return 0;
+
if (!symbols)
return -EINVAL;
- scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx);
- if (scn)
- data = elf_getdata(scn, NULL);
+
+ scn = elf_sec_by_idx(obj, obj->efile.maps_shndx);
+ data = elf_sec_data(obj, scn);
if (!scn || !data) {
- pr_warning("failed to get Elf_Data from map section %d\n",
- obj->efile.maps_shndx);
+ pr_warn("elf: failed to get legacy map definitions for %s\n",
+ obj->path);
return -EINVAL;
}
@@ -604,7 +1773,8 @@
*
* TODO: Detect array of map and report error.
*/
- for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+ nr_syms = symbols->d_size / sizeof(GElf_Sym);
+ for (i = 0; i < nr_syms; i++) {
GElf_Sym sym;
if (!gelf_getsym(symbols, i, &sym))
@@ -613,68 +1783,57 @@
continue;
nr_maps++;
}
-
- /* Alloc obj->maps and fill nr_maps. */
- pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
- nr_maps, data->d_size);
-
- if (!nr_maps)
- return 0;
-
/* Assume equally sized map definitions */
- map_def_sz = data->d_size / nr_maps;
- if (!data->d_size || (data->d_size % nr_maps) != 0) {
- pr_warning("unable to determine map definition size "
- "section %s, %d maps in %zd bytes\n",
- obj->path, nr_maps, data->d_size);
+ pr_debug("elf: found %d legacy map definitions (%zd bytes) in %s\n",
+ nr_maps, data->d_size, obj->path);
+
+ if (!data->d_size || nr_maps == 0 || (data->d_size % nr_maps) != 0) {
+ pr_warn("elf: unable to determine legacy map definition size in %s\n",
+ obj->path);
return -EINVAL;
}
+ map_def_sz = data->d_size / nr_maps;
- obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
- if (!obj->maps) {
- pr_warning("alloc maps for object failed\n");
- return -ENOMEM;
- }
- obj->nr_maps = nr_maps;
-
- /*
- * fill all fd with -1 so won't close incorrect
- * fd (fd=0 is stdin) when failure (zclose won't close
- * negative fd)).
- */
- for (i = 0; i < nr_maps; i++)
- obj->maps[i].fd = -1;
-
- /*
- * Fill obj->maps using data in "maps" section.
- */
- for (i = 0, map_idx = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
+ /* Fill obj->maps using data in "maps" section. */
+ for (i = 0; i < nr_syms; i++) {
GElf_Sym sym;
const char *map_name;
struct bpf_map_def *def;
+ struct bpf_map *map;
if (!gelf_getsym(symbols, i, &sym))
continue;
if (sym.st_shndx != obj->efile.maps_shndx)
continue;
- map_name = elf_strptr(obj->efile.elf,
- obj->efile.strtabidx,
- sym.st_name);
- obj->maps[map_idx].offset = sym.st_value;
+ map = bpf_object__add_map(obj);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ map_name = elf_sym_str(obj, sym.st_name);
+ if (!map_name) {
+ pr_warn("failed to get map #%d name sym string for obj %s\n",
+ i, obj->path);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ map->libbpf_type = LIBBPF_MAP_UNSPEC;
+ map->sec_idx = sym.st_shndx;
+ map->sec_offset = sym.st_value;
+ pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n",
+ map_name, map->sec_idx, map->sec_offset);
if (sym.st_value + map_def_sz > data->d_size) {
- pr_warning("corrupted maps section in %s: last map \"%s\" too small\n",
- obj->path, map_name);
+ pr_warn("corrupted maps section in %s: last map \"%s\" too small\n",
+ obj->path, map_name);
return -EINVAL;
}
- obj->maps[map_idx].name = strdup(map_name);
- if (!obj->maps[map_idx].name) {
- pr_warning("failed to alloc map name\n");
+ map->name = strdup(map_name);
+ if (!map->name) {
+ pr_warn("failed to alloc map name\n");
return -ENOMEM;
}
- pr_debug("map %d is \"%s\"\n", map_idx,
- obj->maps[map_idx].name);
+ pr_debug("map %d is \"%s\"\n", i, map->name);
def = (struct bpf_map_def *)(data->d_buf + sym.st_value);
/*
* If the definition of the map in the object file fits in
@@ -683,7 +1842,7 @@
* calloc above.
*/
if (map_def_sz <= sizeof(struct bpf_map_def)) {
- memcpy(&obj->maps[map_idx].def, def, map_def_sz);
+ memcpy(&map->def, def, map_def_sz);
} else {
/*
* Here the map structure being read is bigger than what
@@ -692,367 +1851,1803 @@
* incompatible.
*/
char *b;
+
for (b = ((char *)def) + sizeof(struct bpf_map_def);
b < ((char *)def) + map_def_sz; b++) {
if (*b != 0) {
- pr_warning("maps section in %s: \"%s\" "
- "has unrecognized, non-zero "
- "options\n",
- obj->path, map_name);
- return -EINVAL;
+ pr_warn("maps section in %s: \"%s\" has unrecognized, non-zero options\n",
+ obj->path, map_name);
+ if (strict)
+ return -EINVAL;
}
}
- memcpy(&obj->maps[map_idx].def, def,
- sizeof(struct bpf_map_def));
+ memcpy(&map->def, def, sizeof(struct bpf_map_def));
}
- map_idx++;
+ }
+ return 0;
+}
+
+static const struct btf_type *
+skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id)
+{
+ const struct btf_type *t = btf__type_by_id(btf, id);
+
+ if (res_id)
+ *res_id = id;
+
+ while (btf_is_mod(t) || btf_is_typedef(t)) {
+ if (res_id)
+ *res_id = t->type;
+ t = btf__type_by_id(btf, t->type);
}
- qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map);
+ return t;
+}
+
+static const struct btf_type *
+resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id)
+{
+ const struct btf_type *t;
+
+ t = skip_mods_and_typedefs(btf, id, NULL);
+ if (!btf_is_ptr(t))
+ return NULL;
+
+ t = skip_mods_and_typedefs(btf, t->type, res_id);
+
+ return btf_is_func_proto(t) ? t : NULL;
+}
+
+static const char *btf_kind_str(const struct btf_type *t)
+{
+ switch (btf_kind(t)) {
+ case BTF_KIND_UNKN: return "void";
+ case BTF_KIND_INT: return "int";
+ case BTF_KIND_PTR: return "ptr";
+ case BTF_KIND_ARRAY: return "array";
+ case BTF_KIND_STRUCT: return "struct";
+ case BTF_KIND_UNION: return "union";
+ case BTF_KIND_ENUM: return "enum";
+ case BTF_KIND_FWD: return "fwd";
+ case BTF_KIND_TYPEDEF: return "typedef";
+ case BTF_KIND_VOLATILE: return "volatile";
+ case BTF_KIND_CONST: return "const";
+ case BTF_KIND_RESTRICT: return "restrict";
+ case BTF_KIND_FUNC: return "func";
+ case BTF_KIND_FUNC_PROTO: return "func_proto";
+ case BTF_KIND_VAR: return "var";
+ case BTF_KIND_DATASEC: return "datasec";
+ default: return "unknown";
+ }
+}
+
+/*
+ * Fetch integer attribute of BTF map definition. Such attributes are
+ * represented using a pointer to an array, in which dimensionality of array
+ * encodes specified integer value. E.g., int (*type)[BPF_MAP_TYPE_ARRAY];
+ * encodes `type => BPF_MAP_TYPE_ARRAY` key/value pair completely using BTF
+ * type definition, while using only sizeof(void *) space in ELF data section.
+ */
+static bool get_map_field_int(const char *map_name, const struct btf *btf,
+ const struct btf_member *m, __u32 *res)
+{
+ const struct btf_type *t = skip_mods_and_typedefs(btf, m->type, NULL);
+ const char *name = btf__name_by_offset(btf, m->name_off);
+ const struct btf_array *arr_info;
+ const struct btf_type *arr_t;
+
+ if (!btf_is_ptr(t)) {
+ pr_warn("map '%s': attr '%s': expected PTR, got %s.\n",
+ map_name, name, btf_kind_str(t));
+ return false;
+ }
+
+ arr_t = btf__type_by_id(btf, t->type);
+ if (!arr_t) {
+ pr_warn("map '%s': attr '%s': type [%u] not found.\n",
+ map_name, name, t->type);
+ return false;
+ }
+ if (!btf_is_array(arr_t)) {
+ pr_warn("map '%s': attr '%s': expected ARRAY, got %s.\n",
+ map_name, name, btf_kind_str(arr_t));
+ return false;
+ }
+ arr_info = btf_array(arr_t);
+ *res = arr_info->nelems;
+ return true;
+}
+
+static int build_map_pin_path(struct bpf_map *map, const char *path)
+{
+ char buf[PATH_MAX];
+ int len;
+
+ if (!path)
+ path = "/sys/fs/bpf";
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
+ if (len < 0)
+ return -EINVAL;
+ else if (len >= PATH_MAX)
+ return -ENAMETOOLONG;
+
+ return bpf_map__set_pin_path(map, buf);
+}
+
+
+static int parse_btf_map_def(struct bpf_object *obj,
+ struct bpf_map *map,
+ const struct btf_type *def,
+ bool strict, bool is_inner,
+ const char *pin_root_path)
+{
+ const struct btf_type *t;
+ const struct btf_member *m;
+ int vlen, i;
+
+ vlen = btf_vlen(def);
+ m = btf_members(def);
+ for (i = 0; i < vlen; i++, m++) {
+ const char *name = btf__name_by_offset(obj->btf, m->name_off);
+
+ if (!name) {
+ pr_warn("map '%s': invalid field #%d.\n", map->name, i);
+ return -EINVAL;
+ }
+ if (strcmp(name, "type") == 0) {
+ if (!get_map_field_int(map->name, obj->btf, m,
+ &map->def.type))
+ return -EINVAL;
+ pr_debug("map '%s': found type = %u.\n",
+ map->name, map->def.type);
+ } else if (strcmp(name, "max_entries") == 0) {
+ if (!get_map_field_int(map->name, obj->btf, m,
+ &map->def.max_entries))
+ return -EINVAL;
+ pr_debug("map '%s': found max_entries = %u.\n",
+ map->name, map->def.max_entries);
+ } else if (strcmp(name, "map_flags") == 0) {
+ if (!get_map_field_int(map->name, obj->btf, m,
+ &map->def.map_flags))
+ return -EINVAL;
+ pr_debug("map '%s': found map_flags = %u.\n",
+ map->name, map->def.map_flags);
+ } else if (strcmp(name, "numa_node") == 0) {
+ if (!get_map_field_int(map->name, obj->btf, m, &map->numa_node))
+ return -EINVAL;
+ pr_debug("map '%s': found numa_node = %u.\n", map->name, map->numa_node);
+ } else if (strcmp(name, "key_size") == 0) {
+ __u32 sz;
+
+ if (!get_map_field_int(map->name, obj->btf, m, &sz))
+ return -EINVAL;
+ pr_debug("map '%s': found key_size = %u.\n",
+ map->name, sz);
+ if (map->def.key_size && map->def.key_size != sz) {
+ pr_warn("map '%s': conflicting key size %u != %u.\n",
+ map->name, map->def.key_size, sz);
+ return -EINVAL;
+ }
+ map->def.key_size = sz;
+ } else if (strcmp(name, "key") == 0) {
+ __s64 sz;
+
+ t = btf__type_by_id(obj->btf, m->type);
+ if (!t) {
+ pr_warn("map '%s': key type [%d] not found.\n",
+ map->name, m->type);
+ return -EINVAL;
+ }
+ if (!btf_is_ptr(t)) {
+ pr_warn("map '%s': key spec is not PTR: %s.\n",
+ map->name, btf_kind_str(t));
+ return -EINVAL;
+ }
+ sz = btf__resolve_size(obj->btf, t->type);
+ if (sz < 0) {
+ pr_warn("map '%s': can't determine key size for type [%u]: %zd.\n",
+ map->name, t->type, (ssize_t)sz);
+ return sz;
+ }
+ pr_debug("map '%s': found key [%u], sz = %zd.\n",
+ map->name, t->type, (ssize_t)sz);
+ if (map->def.key_size && map->def.key_size != sz) {
+ pr_warn("map '%s': conflicting key size %u != %zd.\n",
+ map->name, map->def.key_size, (ssize_t)sz);
+ return -EINVAL;
+ }
+ map->def.key_size = sz;
+ map->btf_key_type_id = t->type;
+ } else if (strcmp(name, "value_size") == 0) {
+ __u32 sz;
+
+ if (!get_map_field_int(map->name, obj->btf, m, &sz))
+ return -EINVAL;
+ pr_debug("map '%s': found value_size = %u.\n",
+ map->name, sz);
+ if (map->def.value_size && map->def.value_size != sz) {
+ pr_warn("map '%s': conflicting value size %u != %u.\n",
+ map->name, map->def.value_size, sz);
+ return -EINVAL;
+ }
+ map->def.value_size = sz;
+ } else if (strcmp(name, "value") == 0) {
+ __s64 sz;
+
+ t = btf__type_by_id(obj->btf, m->type);
+ if (!t) {
+ pr_warn("map '%s': value type [%d] not found.\n",
+ map->name, m->type);
+ return -EINVAL;
+ }
+ if (!btf_is_ptr(t)) {
+ pr_warn("map '%s': value spec is not PTR: %s.\n",
+ map->name, btf_kind_str(t));
+ return -EINVAL;
+ }
+ sz = btf__resolve_size(obj->btf, t->type);
+ if (sz < 0) {
+ pr_warn("map '%s': can't determine value size for type [%u]: %zd.\n",
+ map->name, t->type, (ssize_t)sz);
+ return sz;
+ }
+ pr_debug("map '%s': found value [%u], sz = %zd.\n",
+ map->name, t->type, (ssize_t)sz);
+ if (map->def.value_size && map->def.value_size != sz) {
+ pr_warn("map '%s': conflicting value size %u != %zd.\n",
+ map->name, map->def.value_size, (ssize_t)sz);
+ return -EINVAL;
+ }
+ map->def.value_size = sz;
+ map->btf_value_type_id = t->type;
+ }
+ else if (strcmp(name, "values") == 0) {
+ int err;
+
+ if (is_inner) {
+ pr_warn("map '%s': multi-level inner maps not supported.\n",
+ map->name);
+ return -ENOTSUP;
+ }
+ if (i != vlen - 1) {
+ pr_warn("map '%s': '%s' member should be last.\n",
+ map->name, name);
+ return -EINVAL;
+ }
+ if (!bpf_map_type__is_map_in_map(map->def.type)) {
+ pr_warn("map '%s': should be map-in-map.\n",
+ map->name);
+ return -ENOTSUP;
+ }
+ if (map->def.value_size && map->def.value_size != 4) {
+ pr_warn("map '%s': conflicting value size %u != 4.\n",
+ map->name, map->def.value_size);
+ return -EINVAL;
+ }
+ map->def.value_size = 4;
+ t = btf__type_by_id(obj->btf, m->type);
+ if (!t) {
+ pr_warn("map '%s': map-in-map inner type [%d] not found.\n",
+ map->name, m->type);
+ return -EINVAL;
+ }
+ if (!btf_is_array(t) || btf_array(t)->nelems) {
+ pr_warn("map '%s': map-in-map inner spec is not a zero-sized array.\n",
+ map->name);
+ return -EINVAL;
+ }
+ t = skip_mods_and_typedefs(obj->btf, btf_array(t)->type,
+ NULL);
+ if (!btf_is_ptr(t)) {
+ pr_warn("map '%s': map-in-map inner def is of unexpected kind %s.\n",
+ map->name, btf_kind_str(t));
+ return -EINVAL;
+ }
+ t = skip_mods_and_typedefs(obj->btf, t->type, NULL);
+ if (!btf_is_struct(t)) {
+ pr_warn("map '%s': map-in-map inner def is of unexpected kind %s.\n",
+ map->name, btf_kind_str(t));
+ return -EINVAL;
+ }
+
+ map->inner_map = calloc(1, sizeof(*map->inner_map));
+ if (!map->inner_map)
+ return -ENOMEM;
+ map->inner_map->sec_idx = obj->efile.btf_maps_shndx;
+ map->inner_map->name = malloc(strlen(map->name) +
+ sizeof(".inner") + 1);
+ if (!map->inner_map->name)
+ return -ENOMEM;
+ sprintf(map->inner_map->name, "%s.inner", map->name);
+
+ err = parse_btf_map_def(obj, map->inner_map, t, strict,
+ true /* is_inner */, NULL);
+ if (err)
+ return err;
+ } else if (strcmp(name, "pinning") == 0) {
+ __u32 val;
+ int err;
+
+ if (is_inner) {
+ pr_debug("map '%s': inner def can't be pinned.\n",
+ map->name);
+ return -EINVAL;
+ }
+ if (!get_map_field_int(map->name, obj->btf, m, &val))
+ return -EINVAL;
+ pr_debug("map '%s': found pinning = %u.\n",
+ map->name, val);
+
+ if (val != LIBBPF_PIN_NONE &&
+ val != LIBBPF_PIN_BY_NAME) {
+ pr_warn("map '%s': invalid pinning value %u.\n",
+ map->name, val);
+ return -EINVAL;
+ }
+ if (val == LIBBPF_PIN_BY_NAME) {
+ err = build_map_pin_path(map, pin_root_path);
+ if (err) {
+ pr_warn("map '%s': couldn't build pin path.\n",
+ map->name);
+ return err;
+ }
+ }
+ } else {
+ if (strict) {
+ pr_warn("map '%s': unknown field '%s'.\n",
+ map->name, name);
+ return -ENOTSUP;
+ }
+ pr_debug("map '%s': ignoring unknown field '%s'.\n",
+ map->name, name);
+ }
+ }
+
+ if (map->def.type == BPF_MAP_TYPE_UNSPEC) {
+ pr_warn("map '%s': map type isn't specified.\n", map->name);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int bpf_object__init_user_btf_map(struct bpf_object *obj,
+ const struct btf_type *sec,
+ int var_idx, int sec_idx,
+ const Elf_Data *data, bool strict,
+ const char *pin_root_path)
+{
+ const struct btf_type *var, *def;
+ const struct btf_var_secinfo *vi;
+ const struct btf_var *var_extra;
+ const char *map_name;
+ struct bpf_map *map;
+
+ vi = btf_var_secinfos(sec) + var_idx;
+ var = btf__type_by_id(obj->btf, vi->type);
+ var_extra = btf_var(var);
+ map_name = btf__name_by_offset(obj->btf, var->name_off);
+
+ if (map_name == NULL || map_name[0] == '\0') {
+ pr_warn("map #%d: empty name.\n", var_idx);
+ return -EINVAL;
+ }
+ if ((__u64)vi->offset + vi->size > data->d_size) {
+ pr_warn("map '%s' BTF data is corrupted.\n", map_name);
+ return -EINVAL;
+ }
+ if (!btf_is_var(var)) {
+ pr_warn("map '%s': unexpected var kind %s.\n",
+ map_name, btf_kind_str(var));
+ return -EINVAL;
+ }
+ if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED &&
+ var_extra->linkage != BTF_VAR_STATIC) {
+ pr_warn("map '%s': unsupported var linkage %u.\n",
+ map_name, var_extra->linkage);
+ return -EOPNOTSUPP;
+ }
+
+ def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
+ if (!btf_is_struct(def)) {
+ pr_warn("map '%s': unexpected def kind %s.\n",
+ map_name, btf_kind_str(var));
+ return -EINVAL;
+ }
+ if (def->size > vi->size) {
+ pr_warn("map '%s': invalid def size.\n", map_name);
+ return -EINVAL;
+ }
+
+ map = bpf_object__add_map(obj);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+ map->name = strdup(map_name);
+ if (!map->name) {
+ pr_warn("map '%s': failed to alloc map name.\n", map_name);
+ return -ENOMEM;
+ }
+ map->libbpf_type = LIBBPF_MAP_UNSPEC;
+ map->def.type = BPF_MAP_TYPE_UNSPEC;
+ map->sec_idx = sec_idx;
+ map->sec_offset = vi->offset;
+ map->btf_var_idx = var_idx;
+ pr_debug("map '%s': at sec_idx %d, offset %zu.\n",
+ map_name, map->sec_idx, map->sec_offset);
+
+ return parse_btf_map_def(obj, map, def, strict, false, pin_root_path);
+}
+
+static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
+ const char *pin_root_path)
+{
+ const struct btf_type *sec = NULL;
+ int nr_types, i, vlen, err;
+ const struct btf_type *t;
+ const char *name;
+ Elf_Data *data;
+ Elf_Scn *scn;
+
+ if (obj->efile.btf_maps_shndx < 0)
+ return 0;
+
+ scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx);
+ data = elf_sec_data(obj, scn);
+ if (!scn || !data) {
+ pr_warn("elf: failed to get %s map definitions for %s\n",
+ MAPS_ELF_SEC, obj->path);
+ return -EINVAL;
+ }
+
+ nr_types = btf__get_nr_types(obj->btf);
+ for (i = 1; i <= nr_types; i++) {
+ t = btf__type_by_id(obj->btf, i);
+ if (!btf_is_datasec(t))
+ continue;
+ name = btf__name_by_offset(obj->btf, t->name_off);
+ if (strcmp(name, MAPS_ELF_SEC) == 0) {
+ sec = t;
+ obj->efile.btf_maps_sec_btf_id = i;
+ break;
+ }
+ }
+
+ if (!sec) {
+ pr_warn("DATASEC '%s' not found.\n", MAPS_ELF_SEC);
+ return -ENOENT;
+ }
+
+ vlen = btf_vlen(sec);
+ for (i = 0; i < vlen; i++) {
+ err = bpf_object__init_user_btf_map(obj, sec, i,
+ obj->efile.btf_maps_shndx,
+ data, strict,
+ pin_root_path);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int bpf_object__init_maps(struct bpf_object *obj,
+ const struct bpf_object_open_opts *opts)
+{
+ const char *pin_root_path;
+ bool strict;
+ int err;
+
+ strict = !OPTS_GET(opts, relaxed_maps, false);
+ pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
+
+ err = bpf_object__init_user_maps(obj, strict);
+ err = err ?: bpf_object__init_user_btf_maps(obj, strict, pin_root_path);
+ err = err ?: bpf_object__init_global_data_maps(obj);
+ err = err ?: bpf_object__init_kconfig_map(obj);
+ err = err ?: bpf_object__init_struct_ops_maps(obj);
+ if (err)
+ return err;
+
return 0;
}
static bool section_have_execinstr(struct bpf_object *obj, int idx)
{
- Elf_Scn *scn;
GElf_Shdr sh;
- scn = elf_getscn(obj->efile.elf, idx);
- if (!scn)
+ if (elf_sec_hdr(obj, elf_sec_by_idx(obj, idx), &sh))
return false;
- if (gelf_getshdr(scn, &sh) != &sh)
- return false;
+ return sh.sh_flags & SHF_EXECINSTR;
+}
- if (sh.sh_flags & SHF_EXECINSTR)
+static bool btf_needs_sanitization(struct bpf_object *obj)
+{
+ bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC);
+ bool has_datasec = kernel_supports(FEAT_BTF_DATASEC);
+ bool has_func = kernel_supports(FEAT_BTF_FUNC);
+
+ return !has_func || !has_datasec || !has_func_global;
+}
+
+static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
+{
+ bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC);
+ bool has_datasec = kernel_supports(FEAT_BTF_DATASEC);
+ bool has_func = kernel_supports(FEAT_BTF_FUNC);
+ struct btf_type *t;
+ int i, j, vlen;
+
+ for (i = 1; i <= btf__get_nr_types(btf); i++) {
+ t = (struct btf_type *)btf__type_by_id(btf, i);
+
+ if (!has_datasec && btf_is_var(t)) {
+ /* replace VAR with INT */
+ t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
+ /*
+ * using size = 1 is the safest choice, 4 will be too
+ * big and cause kernel BTF validation failure if
+ * original variable took less than 4 bytes
+ */
+ t->size = 1;
+ *(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
+ } else if (!has_datasec && btf_is_datasec(t)) {
+ /* replace DATASEC with STRUCT */
+ const struct btf_var_secinfo *v = btf_var_secinfos(t);
+ struct btf_member *m = btf_members(t);
+ struct btf_type *vt;
+ char *name;
+
+ name = (char *)btf__name_by_offset(btf, t->name_off);
+ while (*name) {
+ if (*name == '.')
+ *name = '_';
+ name++;
+ }
+
+ vlen = btf_vlen(t);
+ t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, vlen);
+ for (j = 0; j < vlen; j++, v++, m++) {
+ /* order of field assignments is important */
+ m->offset = v->offset * 8;
+ m->type = v->type;
+ /* preserve variable name as member name */
+ vt = (void *)btf__type_by_id(btf, v->type);
+ m->name_off = vt->name_off;
+ }
+ } else if (!has_func && btf_is_func_proto(t)) {
+ /* replace FUNC_PROTO with ENUM */
+ vlen = btf_vlen(t);
+ t->info = BTF_INFO_ENC(BTF_KIND_ENUM, 0, vlen);
+ t->size = sizeof(__u32); /* kernel enforced */
+ } else if (!has_func && btf_is_func(t)) {
+ /* replace FUNC with TYPEDEF */
+ t->info = BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0);
+ } else if (!has_func_global && btf_is_func(t)) {
+ /* replace BTF_FUNC_GLOBAL with BTF_FUNC_STATIC */
+ t->info = BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0);
+ }
+ }
+}
+
+static bool libbpf_needs_btf(const struct bpf_object *obj)
+{
+ return obj->efile.btf_maps_shndx >= 0 ||
+ obj->efile.st_ops_shndx >= 0 ||
+ obj->nr_extern > 0;
+}
+
+static bool kernel_needs_btf(const struct bpf_object *obj)
+{
+ return obj->efile.st_ops_shndx >= 0;
+}
+
+static int bpf_object__init_btf(struct bpf_object *obj,
+ Elf_Data *btf_data,
+ Elf_Data *btf_ext_data)
+{
+ int err = -ENOENT;
+
+ if (btf_data) {
+ obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
+ if (IS_ERR(obj->btf)) {
+ err = PTR_ERR(obj->btf);
+ obj->btf = NULL;
+ pr_warn("Error loading ELF section %s: %d.\n",
+ BTF_ELF_SEC, err);
+ goto out;
+ }
+ /* enforce 8-byte pointers for BPF-targeted BTFs */
+ btf__set_pointer_size(obj->btf, 8);
+ err = 0;
+ }
+ if (btf_ext_data) {
+ if (!obj->btf) {
+ pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
+ BTF_EXT_ELF_SEC, BTF_ELF_SEC);
+ goto out;
+ }
+ obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
+ btf_ext_data->d_size);
+ if (IS_ERR(obj->btf_ext)) {
+ pr_warn("Error loading ELF section %s: %ld. Ignored and continue.\n",
+ BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext));
+ obj->btf_ext = NULL;
+ goto out;
+ }
+ }
+out:
+ if (err && libbpf_needs_btf(obj)) {
+ pr_warn("BTF is required, but is missing or corrupted.\n");
+ return err;
+ }
+ return 0;
+}
+
+static int bpf_object__finalize_btf(struct bpf_object *obj)
+{
+ int err;
+
+ if (!obj->btf)
+ return 0;
+
+ err = btf__finalize_data(obj, obj->btf);
+ if (err) {
+ pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
+ return err;
+ }
+
+ return 0;
+}
+
+static inline bool libbpf_prog_needs_vmlinux_btf(struct bpf_program *prog)
+{
+ if (prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
+ prog->type == BPF_PROG_TYPE_LSM)
+ return true;
+
+ /* BPF_PROG_TYPE_TRACING programs which do not attach to other programs
+ * also need vmlinux BTF
+ */
+ if (prog->type == BPF_PROG_TYPE_TRACING && !prog->attach_prog_fd)
return true;
return false;
}
-static int bpf_object__elf_collect(struct bpf_object *obj)
+static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
{
- Elf *elf = obj->efile.elf;
- GElf_Ehdr *ep = &obj->efile.ehdr;
- Elf_Scn *scn = NULL;
- int idx = 0, err = 0;
+ bool need_vmlinux_btf = false;
+ struct bpf_program *prog;
+ int i, err;
- /* Elf is corrupted/truncated, avoid calling elf_strptr. */
- if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
- pr_warning("failed to get e_shstrndx from %s\n",
- obj->path);
- return -LIBBPF_ERRNO__FORMAT;
+ /* CO-RE relocations need kernel BTF */
+ if (obj->btf_ext && obj->btf_ext->core_relo_info.len)
+ need_vmlinux_btf = true;
+
+ /* Support for typed ksyms needs kernel BTF */
+ for (i = 0; i < obj->nr_extern; i++) {
+ const struct extern_desc *ext;
+
+ ext = &obj->externs[i];
+ if (ext->type == EXT_KSYM && ext->ksym.type_id) {
+ need_vmlinux_btf = true;
+ break;
+ }
}
- while ((scn = elf_nextscn(elf, scn)) != NULL) {
- char *name;
- GElf_Shdr sh;
- Elf_Data *data;
-
- idx++;
- if (gelf_getshdr(scn, &sh) != &sh) {
- pr_warning("failed to get section(%d) header from %s\n",
- idx, obj->path);
- err = -LIBBPF_ERRNO__FORMAT;
- goto out;
+ bpf_object__for_each_program(prog, obj) {
+ if (!prog->load)
+ continue;
+ if (libbpf_prog_needs_vmlinux_btf(prog)) {
+ need_vmlinux_btf = true;
+ break;
}
-
- name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
- if (!name) {
- pr_warning("failed to get section(%d) name from %s\n",
- idx, obj->path);
- err = -LIBBPF_ERRNO__FORMAT;
- goto out;
- }
-
- data = elf_getdata(scn, 0);
- if (!data) {
- pr_warning("failed to get section(%d) data from %s(%s)\n",
- idx, name, obj->path);
- err = -LIBBPF_ERRNO__FORMAT;
- goto out;
- }
- pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
- idx, name, (unsigned long)data->d_size,
- (int)sh.sh_link, (unsigned long)sh.sh_flags,
- (int)sh.sh_type);
-
- if (strcmp(name, "license") == 0)
- err = bpf_object__init_license(obj,
- data->d_buf,
- data->d_size);
- else if (strcmp(name, "version") == 0)
- err = bpf_object__init_kversion(obj,
- data->d_buf,
- data->d_size);
- else if (strcmp(name, "maps") == 0)
- obj->efile.maps_shndx = idx;
- else if (strcmp(name, BTF_ELF_SEC) == 0) {
- obj->btf = btf__new(data->d_buf, data->d_size,
- __pr_debug);
- if (IS_ERR(obj->btf)) {
- pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
- BTF_ELF_SEC, PTR_ERR(obj->btf));
- obj->btf = NULL;
- }
- } else if (sh.sh_type == SHT_SYMTAB) {
- if (obj->efile.symbols) {
- pr_warning("bpf: multiple SYMTAB in %s\n",
- obj->path);
- err = -LIBBPF_ERRNO__FORMAT;
- } else {
- obj->efile.symbols = data;
- obj->efile.strtabidx = sh.sh_link;
- }
- } else if ((sh.sh_type == SHT_PROGBITS) &&
- (sh.sh_flags & SHF_EXECINSTR) &&
- (data->d_size > 0)) {
- if (strcmp(name, ".text") == 0)
- obj->efile.text_shndx = idx;
- err = bpf_object__add_program(obj, data->d_buf,
- data->d_size, name, idx);
- if (err) {
- char errmsg[STRERR_BUFSIZE];
- char *cp = str_error(-err, errmsg, sizeof(errmsg));
-
- pr_warning("failed to alloc program %s (%s): %s",
- name, obj->path, cp);
- }
- } else if (sh.sh_type == SHT_REL) {
- void *reloc = obj->efile.reloc;
- int nr_reloc = obj->efile.nr_reloc + 1;
- int sec = sh.sh_info; /* points to other section */
-
- /* Only do relo for section with exec instructions */
- if (!section_have_execinstr(obj, sec)) {
- pr_debug("skip relo %s(%d) for section(%d)\n",
- name, idx, sec);
- continue;
- }
-
- reloc = reallocarray(reloc, nr_reloc,
- sizeof(*obj->efile.reloc));
- if (!reloc) {
- pr_warning("realloc failed\n");
- err = -ENOMEM;
- } else {
- int n = nr_reloc - 1;
-
- obj->efile.reloc = reloc;
- obj->efile.nr_reloc = nr_reloc;
-
- obj->efile.reloc[n].shdr = sh;
- obj->efile.reloc[n].data = data;
- }
- } else {
- pr_debug("skip section(%d) %s\n", idx, name);
- }
- if (err)
- goto out;
}
- if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) {
- pr_warning("Corrupted ELF file: index of strtab invalid\n");
- return LIBBPF_ERRNO__FORMAT;
+ if (!need_vmlinux_btf)
+ return 0;
+
+ obj->btf_vmlinux = libbpf_find_kernel_btf();
+ if (IS_ERR(obj->btf_vmlinux)) {
+ err = PTR_ERR(obj->btf_vmlinux);
+ pr_warn("Error loading vmlinux BTF: %d\n", err);
+ obj->btf_vmlinux = NULL;
+ return err;
}
- if (obj->efile.maps_shndx >= 0) {
- err = bpf_object__init_maps(obj);
- if (err)
- goto out;
+ return 0;
+}
+
+static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
+{
+ struct btf *kern_btf = obj->btf;
+ bool btf_mandatory, sanitize;
+ int err = 0;
+
+ if (!obj->btf)
+ return 0;
+
+ if (!kernel_supports(FEAT_BTF)) {
+ if (kernel_needs_btf(obj)) {
+ err = -EOPNOTSUPP;
+ goto report;
+ }
+ pr_debug("Kernel doesn't support BTF, skipping uploading it.\n");
+ return 0;
}
- err = bpf_object__init_prog_names(obj);
-out:
+
+ sanitize = btf_needs_sanitization(obj);
+ if (sanitize) {
+ const void *raw_data;
+ __u32 sz;
+
+ /* clone BTF to sanitize a copy and leave the original intact */
+ raw_data = btf__get_raw_data(obj->btf, &sz);
+ kern_btf = btf__new(raw_data, sz);
+ if (IS_ERR(kern_btf))
+ return PTR_ERR(kern_btf);
+
+ /* enforce 8-byte pointers for BPF-targeted BTFs */
+ btf__set_pointer_size(obj->btf, 8);
+ bpf_object__sanitize_btf(obj, kern_btf);
+ }
+
+ err = btf__load(kern_btf);
+ if (sanitize) {
+ if (!err) {
+ /* move fd to libbpf's BTF */
+ btf__set_fd(obj->btf, btf__fd(kern_btf));
+ btf__set_fd(kern_btf, -1);
+ }
+ btf__free(kern_btf);
+ }
+report:
+ if (err) {
+ btf_mandatory = kernel_needs_btf(obj);
+ pr_warn("Error loading .BTF into kernel: %d. %s\n", err,
+ btf_mandatory ? "BTF is mandatory, can't proceed."
+ : "BTF is optional, ignoring.");
+ if (!btf_mandatory)
+ err = 0;
+ }
return err;
}
-static struct bpf_program *
-bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
+static const char *elf_sym_str(const struct bpf_object *obj, size_t off)
{
- struct bpf_program *prog;
- size_t i;
+ const char *name;
- for (i = 0; i < obj->nr_programs; i++) {
- prog = &obj->programs[i];
- if (prog->idx == idx)
- return prog;
+ name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, off);
+ if (!name) {
+ pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n",
+ off, obj->path, elf_errmsg(-1));
+ return NULL;
+ }
+
+ return name;
+}
+
+static const char *elf_sec_str(const struct bpf_object *obj, size_t off)
+{
+ const char *name;
+
+ name = elf_strptr(obj->efile.elf, obj->efile.shstrndx, off);
+ if (!name) {
+ pr_warn("elf: failed to get section name string at offset %zu from %s: %s\n",
+ off, obj->path, elf_errmsg(-1));
+ return NULL;
+ }
+
+ return name;
+}
+
+static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx)
+{
+ Elf_Scn *scn;
+
+ scn = elf_getscn(obj->efile.elf, idx);
+ if (!scn) {
+ pr_warn("elf: failed to get section(%zu) from %s: %s\n",
+ idx, obj->path, elf_errmsg(-1));
+ return NULL;
+ }
+ return scn;
+}
+
+static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name)
+{
+ Elf_Scn *scn = NULL;
+ Elf *elf = obj->efile.elf;
+ const char *sec_name;
+
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ sec_name = elf_sec_name(obj, scn);
+ if (!sec_name)
+ return NULL;
+
+ if (strcmp(sec_name, name) != 0)
+ continue;
+
+ return scn;
}
return NULL;
}
+static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr)
+{
+ if (!scn)
+ return -EINVAL;
+
+ if (gelf_getshdr(scn, hdr) != hdr) {
+ pr_warn("elf: failed to get section(%zu) header from %s: %s\n",
+ elf_ndxscn(scn), obj->path, elf_errmsg(-1));
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn)
+{
+ const char *name;
+ GElf_Shdr sh;
+
+ if (!scn)
+ return NULL;
+
+ if (elf_sec_hdr(obj, scn, &sh))
+ return NULL;
+
+ name = elf_sec_str(obj, sh.sh_name);
+ if (!name) {
+ pr_warn("elf: failed to get section(%zu) name from %s: %s\n",
+ elf_ndxscn(scn), obj->path, elf_errmsg(-1));
+ return NULL;
+ }
+
+ return name;
+}
+
+static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn)
+{
+ Elf_Data *data;
+
+ if (!scn)
+ return NULL;
+
+ data = elf_getdata(scn, 0);
+ if (!data) {
+ pr_warn("elf: failed to get section(%zu) %s data from %s: %s\n",
+ elf_ndxscn(scn), elf_sec_name(obj, scn) ?: "<?>",
+ obj->path, elf_errmsg(-1));
+ return NULL;
+ }
+
+ return data;
+}
+
+static int elf_sym_by_sec_off(const struct bpf_object *obj, size_t sec_idx,
+ size_t off, __u32 sym_type, GElf_Sym *sym)
+{
+ Elf_Data *symbols = obj->efile.symbols;
+ size_t n = symbols->d_size / sizeof(GElf_Sym);
+ int i;
+
+ for (i = 0; i < n; i++) {
+ if (!gelf_getsym(symbols, i, sym))
+ continue;
+ if (sym->st_shndx != sec_idx || sym->st_value != off)
+ continue;
+ if (GELF_ST_TYPE(sym->st_info) != sym_type)
+ continue;
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+static bool is_sec_name_dwarf(const char *name)
+{
+ /* approximation, but the actual list is too long */
+ return strncmp(name, ".debug_", sizeof(".debug_") - 1) == 0;
+}
+
+static bool ignore_elf_section(GElf_Shdr *hdr, const char *name)
+{
+ /* no special handling of .strtab */
+ if (hdr->sh_type == SHT_STRTAB)
+ return true;
+
+ /* ignore .llvm_addrsig section as well */
+ if (hdr->sh_type == 0x6FFF4C03 /* SHT_LLVM_ADDRSIG */)
+ return true;
+
+ /* no subprograms will lead to an empty .text section, ignore it */
+ if (hdr->sh_type == SHT_PROGBITS && hdr->sh_size == 0 &&
+ strcmp(name, ".text") == 0)
+ return true;
+
+ /* DWARF sections */
+ if (is_sec_name_dwarf(name))
+ return true;
+
+ if (strncmp(name, ".rel", sizeof(".rel") - 1) == 0) {
+ name += sizeof(".rel") - 1;
+ /* DWARF section relocations */
+ if (is_sec_name_dwarf(name))
+ return true;
+
+ /* .BTF and .BTF.ext don't need relocations */
+ if (strcmp(name, BTF_ELF_SEC) == 0 ||
+ strcmp(name, BTF_EXT_ELF_SEC) == 0)
+ return true;
+ }
+
+ return false;
+}
+
+static int cmp_progs(const void *_a, const void *_b)
+{
+ const struct bpf_program *a = _a;
+ const struct bpf_program *b = _b;
+
+ if (a->sec_idx != b->sec_idx)
+ return a->sec_idx < b->sec_idx ? -1 : 1;
+
+ /* sec_insn_off can't be the same within the section */
+ return a->sec_insn_off < b->sec_insn_off ? -1 : 1;
+}
+
+static int bpf_object__elf_collect(struct bpf_object *obj)
+{
+ Elf *elf = obj->efile.elf;
+ Elf_Data *btf_ext_data = NULL;
+ Elf_Data *btf_data = NULL;
+ int idx = 0, err = 0;
+ const char *name;
+ Elf_Data *data;
+ Elf_Scn *scn;
+ GElf_Shdr sh;
+
+ /* a bunch of ELF parsing functionality depends on processing symbols,
+ * so do the first pass and find the symbol table
+ */
+ scn = NULL;
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ if (elf_sec_hdr(obj, scn, &sh))
+ return -LIBBPF_ERRNO__FORMAT;
+
+ if (sh.sh_type == SHT_SYMTAB) {
+ if (obj->efile.symbols) {
+ pr_warn("elf: multiple symbol tables in %s\n", obj->path);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ data = elf_sec_data(obj, scn);
+ if (!data)
+ return -LIBBPF_ERRNO__FORMAT;
+
+ obj->efile.symbols = data;
+ obj->efile.symbols_shndx = elf_ndxscn(scn);
+ obj->efile.strtabidx = sh.sh_link;
+ }
+ }
+
+ scn = NULL;
+ while ((scn = elf_nextscn(elf, scn)) != NULL) {
+ idx++;
+
+ if (elf_sec_hdr(obj, scn, &sh))
+ return -LIBBPF_ERRNO__FORMAT;
+
+ name = elf_sec_str(obj, sh.sh_name);
+ if (!name)
+ return -LIBBPF_ERRNO__FORMAT;
+
+ if (ignore_elf_section(&sh, name))
+ continue;
+
+ data = elf_sec_data(obj, scn);
+ if (!data)
+ return -LIBBPF_ERRNO__FORMAT;
+
+ pr_debug("elf: section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
+ idx, name, (unsigned long)data->d_size,
+ (int)sh.sh_link, (unsigned long)sh.sh_flags,
+ (int)sh.sh_type);
+
+ if (strcmp(name, "license") == 0) {
+ err = bpf_object__init_license(obj, data->d_buf, data->d_size);
+ if (err)
+ return err;
+ } else if (strcmp(name, "version") == 0) {
+ err = bpf_object__init_kversion(obj, data->d_buf, data->d_size);
+ if (err)
+ return err;
+ } else if (strcmp(name, "maps") == 0) {
+ obj->efile.maps_shndx = idx;
+ } else if (strcmp(name, MAPS_ELF_SEC) == 0) {
+ obj->efile.btf_maps_shndx = idx;
+ } else if (strcmp(name, BTF_ELF_SEC) == 0) {
+ btf_data = data;
+ } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
+ btf_ext_data = data;
+ } else if (sh.sh_type == SHT_SYMTAB) {
+ /* already processed during the first pass above */
+ } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
+ if (sh.sh_flags & SHF_EXECINSTR) {
+ if (strcmp(name, ".text") == 0)
+ obj->efile.text_shndx = idx;
+ err = bpf_object__add_programs(obj, data, name, idx);
+ if (err)
+ return err;
+ } else if (strcmp(name, DATA_SEC) == 0) {
+ obj->efile.data = data;
+ obj->efile.data_shndx = idx;
+ } else if (strcmp(name, RODATA_SEC) == 0) {
+ obj->efile.rodata = data;
+ obj->efile.rodata_shndx = idx;
+ } else if (strcmp(name, STRUCT_OPS_SEC) == 0) {
+ obj->efile.st_ops_data = data;
+ obj->efile.st_ops_shndx = idx;
+ } else {
+ pr_info("elf: skipping unrecognized data section(%d) %s\n",
+ idx, name);
+ }
+ } else if (sh.sh_type == SHT_REL) {
+ int nr_sects = obj->efile.nr_reloc_sects;
+ void *sects = obj->efile.reloc_sects;
+ int sec = sh.sh_info; /* points to other section */
+
+ /* Only do relo for section with exec instructions */
+ if (!section_have_execinstr(obj, sec) &&
+ strcmp(name, ".rel" STRUCT_OPS_SEC) &&
+ strcmp(name, ".rel" MAPS_ELF_SEC)) {
+ pr_info("elf: skipping relo section(%d) %s for section(%d) %s\n",
+ idx, name, sec,
+ elf_sec_name(obj, elf_sec_by_idx(obj, sec)) ?: "<?>");
+ continue;
+ }
+
+ sects = libbpf_reallocarray(sects, nr_sects + 1,
+ sizeof(*obj->efile.reloc_sects));
+ if (!sects)
+ return -ENOMEM;
+
+ obj->efile.reloc_sects = sects;
+ obj->efile.nr_reloc_sects++;
+
+ obj->efile.reloc_sects[nr_sects].shdr = sh;
+ obj->efile.reloc_sects[nr_sects].data = data;
+ } else if (sh.sh_type == SHT_NOBITS && strcmp(name, BSS_SEC) == 0) {
+ obj->efile.bss = data;
+ obj->efile.bss_shndx = idx;
+ } else {
+ pr_info("elf: skipping section(%d) %s (size %zu)\n", idx, name,
+ (size_t)sh.sh_size);
+ }
+ }
+
+ if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) {
+ pr_warn("elf: symbol strings section missing or invalid in %s\n", obj->path);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ /* sort BPF programs by section name and in-section instruction offset
+ * for faster search */
+ qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
+
+ return bpf_object__init_btf(obj, btf_data, btf_ext_data);
+}
+
+static bool sym_is_extern(const GElf_Sym *sym)
+{
+ int bind = GELF_ST_BIND(sym->st_info);
+ /* externs are symbols w/ type=NOTYPE, bind=GLOBAL|WEAK, section=UND */
+ return sym->st_shndx == SHN_UNDEF &&
+ (bind == STB_GLOBAL || bind == STB_WEAK) &&
+ GELF_ST_TYPE(sym->st_info) == STT_NOTYPE;
+}
+
+static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
+{
+ const struct btf_type *t;
+ const char *var_name;
+ int i, n;
+
+ if (!btf)
+ return -ESRCH;
+
+ n = btf__get_nr_types(btf);
+ for (i = 1; i <= n; i++) {
+ t = btf__type_by_id(btf, i);
+
+ if (!btf_is_var(t))
+ continue;
+
+ var_name = btf__name_by_offset(btf, t->name_off);
+ if (strcmp(var_name, ext_name))
+ continue;
+
+ if (btf_var(t)->linkage != BTF_VAR_GLOBAL_EXTERN)
+ return -EINVAL;
+
+ return i;
+ }
+
+ return -ENOENT;
+}
+
+static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) {
+ const struct btf_var_secinfo *vs;
+ const struct btf_type *t;
+ int i, j, n;
+
+ if (!btf)
+ return -ESRCH;
+
+ n = btf__get_nr_types(btf);
+ for (i = 1; i <= n; i++) {
+ t = btf__type_by_id(btf, i);
+
+ if (!btf_is_datasec(t))
+ continue;
+
+ vs = btf_var_secinfos(t);
+ for (j = 0; j < btf_vlen(t); j++, vs++) {
+ if (vs->type == ext_btf_id)
+ return i;
+ }
+ }
+
+ return -ENOENT;
+}
+
+static enum kcfg_type find_kcfg_type(const struct btf *btf, int id,
+ bool *is_signed)
+{
+ const struct btf_type *t;
+ const char *name;
+
+ t = skip_mods_and_typedefs(btf, id, NULL);
+ name = btf__name_by_offset(btf, t->name_off);
+
+ if (is_signed)
+ *is_signed = false;
+ switch (btf_kind(t)) {
+ case BTF_KIND_INT: {
+ int enc = btf_int_encoding(t);
+
+ if (enc & BTF_INT_BOOL)
+ return t->size == 1 ? KCFG_BOOL : KCFG_UNKNOWN;
+ if (is_signed)
+ *is_signed = enc & BTF_INT_SIGNED;
+ if (t->size == 1)
+ return KCFG_CHAR;
+ if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1)))
+ return KCFG_UNKNOWN;
+ return KCFG_INT;
+ }
+ case BTF_KIND_ENUM:
+ if (t->size != 4)
+ return KCFG_UNKNOWN;
+ if (strcmp(name, "libbpf_tristate"))
+ return KCFG_UNKNOWN;
+ return KCFG_TRISTATE;
+ case BTF_KIND_ARRAY:
+ if (btf_array(t)->nelems == 0)
+ return KCFG_UNKNOWN;
+ if (find_kcfg_type(btf, btf_array(t)->type, NULL) != KCFG_CHAR)
+ return KCFG_UNKNOWN;
+ return KCFG_CHAR_ARR;
+ default:
+ return KCFG_UNKNOWN;
+ }
+}
+
+static int cmp_externs(const void *_a, const void *_b)
+{
+ const struct extern_desc *a = _a;
+ const struct extern_desc *b = _b;
+
+ if (a->type != b->type)
+ return a->type < b->type ? -1 : 1;
+
+ if (a->type == EXT_KCFG) {
+ /* descending order by alignment requirements */
+ if (a->kcfg.align != b->kcfg.align)
+ return a->kcfg.align > b->kcfg.align ? -1 : 1;
+ /* ascending order by size, within same alignment class */
+ if (a->kcfg.sz != b->kcfg.sz)
+ return a->kcfg.sz < b->kcfg.sz ? -1 : 1;
+ }
+
+ /* resolve ties by name */
+ return strcmp(a->name, b->name);
+}
+
+static int find_int_btf_id(const struct btf *btf)
+{
+ const struct btf_type *t;
+ int i, n;
+
+ n = btf__get_nr_types(btf);
+ for (i = 1; i <= n; i++) {
+ t = btf__type_by_id(btf, i);
+
+ if (btf_is_int(t) && btf_int_bits(t) == 32)
+ return i;
+ }
+
+ return 0;
+}
+
+static int bpf_object__collect_externs(struct bpf_object *obj)
+{
+ struct btf_type *sec, *kcfg_sec = NULL, *ksym_sec = NULL;
+ const struct btf_type *t;
+ struct extern_desc *ext;
+ int i, n, off;
+ const char *ext_name, *sec_name;
+ Elf_Scn *scn;
+ GElf_Shdr sh;
+
+ if (!obj->efile.symbols)
+ return 0;
+
+ scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx);
+ if (elf_sec_hdr(obj, scn, &sh))
+ return -LIBBPF_ERRNO__FORMAT;
+
+ n = sh.sh_size / sh.sh_entsize;
+ pr_debug("looking for externs among %d symbols...\n", n);
+
+ for (i = 0; i < n; i++) {
+ GElf_Sym sym;
+
+ if (!gelf_getsym(obj->efile.symbols, i, &sym))
+ return -LIBBPF_ERRNO__FORMAT;
+ if (!sym_is_extern(&sym))
+ continue;
+ ext_name = elf_sym_str(obj, sym.st_name);
+ if (!ext_name || !ext_name[0])
+ continue;
+
+ ext = obj->externs;
+ ext = libbpf_reallocarray(ext, obj->nr_extern + 1, sizeof(*ext));
+ if (!ext)
+ return -ENOMEM;
+ obj->externs = ext;
+ ext = &ext[obj->nr_extern];
+ memset(ext, 0, sizeof(*ext));
+ obj->nr_extern++;
+
+ ext->btf_id = find_extern_btf_id(obj->btf, ext_name);
+ if (ext->btf_id <= 0) {
+ pr_warn("failed to find BTF for extern '%s': %d\n",
+ ext_name, ext->btf_id);
+ return ext->btf_id;
+ }
+ t = btf__type_by_id(obj->btf, ext->btf_id);
+ ext->name = btf__name_by_offset(obj->btf, t->name_off);
+ ext->sym_idx = i;
+ ext->is_weak = GELF_ST_BIND(sym.st_info) == STB_WEAK;
+
+ ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id);
+ if (ext->sec_btf_id <= 0) {
+ pr_warn("failed to find BTF for extern '%s' [%d] section: %d\n",
+ ext_name, ext->btf_id, ext->sec_btf_id);
+ return ext->sec_btf_id;
+ }
+ sec = (void *)btf__type_by_id(obj->btf, ext->sec_btf_id);
+ sec_name = btf__name_by_offset(obj->btf, sec->name_off);
+
+ if (strcmp(sec_name, KCONFIG_SEC) == 0) {
+ kcfg_sec = sec;
+ ext->type = EXT_KCFG;
+ ext->kcfg.sz = btf__resolve_size(obj->btf, t->type);
+ if (ext->kcfg.sz <= 0) {
+ pr_warn("failed to resolve size of extern (kcfg) '%s': %d\n",
+ ext_name, ext->kcfg.sz);
+ return ext->kcfg.sz;
+ }
+ ext->kcfg.align = btf__align_of(obj->btf, t->type);
+ if (ext->kcfg.align <= 0) {
+ pr_warn("failed to determine alignment of extern (kcfg) '%s': %d\n",
+ ext_name, ext->kcfg.align);
+ return -EINVAL;
+ }
+ ext->kcfg.type = find_kcfg_type(obj->btf, t->type,
+ &ext->kcfg.is_signed);
+ if (ext->kcfg.type == KCFG_UNKNOWN) {
+ pr_warn("extern (kcfg) '%s' type is unsupported\n", ext_name);
+ return -ENOTSUP;
+ }
+ } else if (strcmp(sec_name, KSYMS_SEC) == 0) {
+ ksym_sec = sec;
+ ext->type = EXT_KSYM;
+ skip_mods_and_typedefs(obj->btf, t->type,
+ &ext->ksym.type_id);
+ } else {
+ pr_warn("unrecognized extern section '%s'\n", sec_name);
+ return -ENOTSUP;
+ }
+ }
+ pr_debug("collected %d externs total\n", obj->nr_extern);
+
+ if (!obj->nr_extern)
+ return 0;
+
+ /* sort externs by type, for kcfg ones also by (align, size, name) */
+ qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs);
+
+ /* for .ksyms section, we need to turn all externs into allocated
+ * variables in BTF to pass kernel verification; we do this by
+ * pretending that each extern is a 8-byte variable
+ */
+ if (ksym_sec) {
+ /* find existing 4-byte integer type in BTF to use for fake
+ * extern variables in DATASEC
+ */
+ int int_btf_id = find_int_btf_id(obj->btf);
+
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+ if (ext->type != EXT_KSYM)
+ continue;
+ pr_debug("extern (ksym) #%d: symbol %d, name %s\n",
+ i, ext->sym_idx, ext->name);
+ }
+
+ sec = ksym_sec;
+ n = btf_vlen(sec);
+ for (i = 0, off = 0; i < n; i++, off += sizeof(int)) {
+ struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i;
+ struct btf_type *vt;
+
+ vt = (void *)btf__type_by_id(obj->btf, vs->type);
+ ext_name = btf__name_by_offset(obj->btf, vt->name_off);
+ ext = find_extern_by_name(obj, ext_name);
+ if (!ext) {
+ pr_warn("failed to find extern definition for BTF var '%s'\n",
+ ext_name);
+ return -ESRCH;
+ }
+ btf_var(vt)->linkage = BTF_VAR_GLOBAL_ALLOCATED;
+ vt->type = int_btf_id;
+ vs->offset = off;
+ vs->size = sizeof(int);
+ }
+ sec->size = off;
+ }
+
+ if (kcfg_sec) {
+ sec = kcfg_sec;
+ /* for kcfg externs calculate their offsets within a .kconfig map */
+ off = 0;
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+ if (ext->type != EXT_KCFG)
+ continue;
+
+ ext->kcfg.data_off = roundup(off, ext->kcfg.align);
+ off = ext->kcfg.data_off + ext->kcfg.sz;
+ pr_debug("extern (kcfg) #%d: symbol %d, off %u, name %s\n",
+ i, ext->sym_idx, ext->kcfg.data_off, ext->name);
+ }
+ sec->size = off;
+ n = btf_vlen(sec);
+ for (i = 0; i < n; i++) {
+ struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i;
+
+ t = btf__type_by_id(obj->btf, vs->type);
+ ext_name = btf__name_by_offset(obj->btf, t->name_off);
+ ext = find_extern_by_name(obj, ext_name);
+ if (!ext) {
+ pr_warn("failed to find extern definition for BTF var '%s'\n",
+ ext_name);
+ return -ESRCH;
+ }
+ btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED;
+ vs->offset = ext->kcfg.data_off;
+ }
+ }
+ return 0;
+}
+
struct bpf_program *
-bpf_object__find_program_by_title(struct bpf_object *obj, const char *title)
+bpf_object__find_program_by_title(const struct bpf_object *obj,
+ const char *title)
{
struct bpf_program *pos;
bpf_object__for_each_program(pos, obj) {
- if (pos->section_name && !strcmp(pos->section_name, title))
+ if (pos->sec_name && !strcmp(pos->sec_name, title))
return pos;
}
return NULL;
}
+static bool prog_is_subprog(const struct bpf_object *obj,
+ const struct bpf_program *prog)
+{
+ /* For legacy reasons, libbpf supports an entry-point BPF programs
+ * without SEC() attribute, i.e., those in the .text section. But if
+ * there are 2 or more such programs in the .text section, they all
+ * must be subprograms called from entry-point BPF programs in
+ * designated SEC()'tions, otherwise there is no way to distinguish
+ * which of those programs should be loaded vs which are a subprogram.
+ * Similarly, if there is a function/program in .text and at least one
+ * other BPF program with custom SEC() attribute, then we just assume
+ * .text programs are subprograms (even if they are not called from
+ * other programs), because libbpf never explicitly supported mixing
+ * SEC()-designated BPF programs and .text entry-point BPF programs.
+ */
+ return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1;
+}
+
+struct bpf_program *
+bpf_object__find_program_by_name(const struct bpf_object *obj,
+ const char *name)
+{
+ struct bpf_program *prog;
+
+ bpf_object__for_each_program(prog, obj) {
+ if (prog_is_subprog(obj, prog))
+ continue;
+ if (!strcmp(prog->name, name))
+ return prog;
+ }
+ return NULL;
+}
+
+static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
+ int shndx)
+{
+ return shndx == obj->efile.data_shndx ||
+ shndx == obj->efile.bss_shndx ||
+ shndx == obj->efile.rodata_shndx;
+}
+
+static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
+ int shndx)
+{
+ return shndx == obj->efile.maps_shndx ||
+ shndx == obj->efile.btf_maps_shndx;
+}
+
+static enum libbpf_map_type
+bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
+{
+ if (shndx == obj->efile.data_shndx)
+ return LIBBPF_MAP_DATA;
+ else if (shndx == obj->efile.bss_shndx)
+ return LIBBPF_MAP_BSS;
+ else if (shndx == obj->efile.rodata_shndx)
+ return LIBBPF_MAP_RODATA;
+ else if (shndx == obj->efile.symbols_shndx)
+ return LIBBPF_MAP_KCONFIG;
+ else
+ return LIBBPF_MAP_UNSPEC;
+}
+
+static int bpf_program__record_reloc(struct bpf_program *prog,
+ struct reloc_desc *reloc_desc,
+ __u32 insn_idx, const char *sym_name,
+ const GElf_Sym *sym, const GElf_Rel *rel)
+{
+ struct bpf_insn *insn = &prog->insns[insn_idx];
+ size_t map_idx, nr_maps = prog->obj->nr_maps;
+ struct bpf_object *obj = prog->obj;
+ __u32 shdr_idx = sym->st_shndx;
+ enum libbpf_map_type type;
+ const char *sym_sec_name;
+ struct bpf_map *map;
+
+ reloc_desc->processed = false;
+
+ /* sub-program call relocation */
+ if (insn->code == (BPF_JMP | BPF_CALL)) {
+ if (insn->src_reg != BPF_PSEUDO_CALL) {
+ pr_warn("prog '%s': incorrect bpf_call opcode\n", prog->name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ /* text_shndx can be 0, if no default "main" program exists */
+ if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
+ sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
+ pr_warn("prog '%s': bad call relo against '%s' in section '%s'\n",
+ prog->name, sym_name, sym_sec_name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ if (sym->st_value % BPF_INSN_SZ) {
+ pr_warn("prog '%s': bad call relo against '%s' at offset %zu\n",
+ prog->name, sym_name, (size_t)sym->st_value);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ reloc_desc->type = RELO_CALL;
+ reloc_desc->insn_idx = insn_idx;
+ reloc_desc->sym_off = sym->st_value;
+ return 0;
+ }
+
+ if (insn->code != (BPF_LD | BPF_IMM | BPF_DW)) {
+ pr_warn("prog '%s': invalid relo against '%s' for insns[%d].code 0x%x\n",
+ prog->name, sym_name, insn_idx, insn->code);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ if (sym_is_extern(sym)) {
+ int sym_idx = GELF_R_SYM(rel->r_info);
+ int i, n = obj->nr_extern;
+ struct extern_desc *ext;
+
+ for (i = 0; i < n; i++) {
+ ext = &obj->externs[i];
+ if (ext->sym_idx == sym_idx)
+ break;
+ }
+ if (i >= n) {
+ pr_warn("prog '%s': extern relo failed to find extern for '%s' (%d)\n",
+ prog->name, sym_name, sym_idx);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ pr_debug("prog '%s': found extern #%d '%s' (sym %d) for insn #%u\n",
+ prog->name, i, ext->name, ext->sym_idx, insn_idx);
+ reloc_desc->type = RELO_EXTERN;
+ reloc_desc->insn_idx = insn_idx;
+ reloc_desc->sym_off = i; /* sym_off stores extern index */
+ return 0;
+ }
+
+ if (!shdr_idx || shdr_idx >= SHN_LORESERVE) {
+ pr_warn("prog '%s': invalid relo against '%s' in special section 0x%x; forgot to initialize global var?..\n",
+ prog->name, sym_name, shdr_idx);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
+ sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
+
+ /* generic map reference relocation */
+ if (type == LIBBPF_MAP_UNSPEC) {
+ if (!bpf_object__shndx_is_maps(obj, shdr_idx)) {
+ pr_warn("prog '%s': bad map relo against '%s' in section '%s'\n",
+ prog->name, sym_name, sym_sec_name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+ map = &obj->maps[map_idx];
+ if (map->libbpf_type != type ||
+ map->sec_idx != sym->st_shndx ||
+ map->sec_offset != sym->st_value)
+ continue;
+ pr_debug("prog '%s': found map %zd (%s, sec %d, off %zu) for insn #%u\n",
+ prog->name, map_idx, map->name, map->sec_idx,
+ map->sec_offset, insn_idx);
+ break;
+ }
+ if (map_idx >= nr_maps) {
+ pr_warn("prog '%s': map relo failed to find map for section '%s', off %zu\n",
+ prog->name, sym_sec_name, (size_t)sym->st_value);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ reloc_desc->type = RELO_LD64;
+ reloc_desc->insn_idx = insn_idx;
+ reloc_desc->map_idx = map_idx;
+ reloc_desc->sym_off = 0; /* sym->st_value determines map_idx */
+ return 0;
+ }
+
+ /* global data map relocation */
+ if (!bpf_object__shndx_is_data(obj, shdr_idx)) {
+ pr_warn("prog '%s': bad data relo against section '%s'\n",
+ prog->name, sym_sec_name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ for (map_idx = 0; map_idx < nr_maps; map_idx++) {
+ map = &obj->maps[map_idx];
+ if (map->libbpf_type != type)
+ continue;
+ pr_debug("prog '%s': found data map %zd (%s, sec %d, off %zu) for insn %u\n",
+ prog->name, map_idx, map->name, map->sec_idx,
+ map->sec_offset, insn_idx);
+ break;
+ }
+ if (map_idx >= nr_maps) {
+ pr_warn("prog '%s': data relo failed to find map for section '%s'\n",
+ prog->name, sym_sec_name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ reloc_desc->type = RELO_DATA;
+ reloc_desc->insn_idx = insn_idx;
+ reloc_desc->map_idx = map_idx;
+ reloc_desc->sym_off = sym->st_value;
+ return 0;
+}
+
+static bool prog_contains_insn(const struct bpf_program *prog, size_t insn_idx)
+{
+ return insn_idx >= prog->sec_insn_off &&
+ insn_idx < prog->sec_insn_off + prog->sec_insn_cnt;
+}
+
+static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj,
+ size_t sec_idx, size_t insn_idx)
+{
+ int l = 0, r = obj->nr_programs - 1, m;
+ struct bpf_program *prog;
+
+ if (!obj->nr_programs)
+ return NULL;
+
+ while (l < r) {
+ m = l + (r - l + 1) / 2;
+ prog = &obj->programs[m];
+
+ if (prog->sec_idx < sec_idx ||
+ (prog->sec_idx == sec_idx && prog->sec_insn_off <= insn_idx))
+ l = m;
+ else
+ r = m - 1;
+ }
+ /* matching program could be at index l, but it still might be the
+ * wrong one, so we need to double check conditions for the last time
+ */
+ prog = &obj->programs[l];
+ if (prog->sec_idx == sec_idx && prog_contains_insn(prog, insn_idx))
+ return prog;
+ return NULL;
+}
+
static int
-bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
- Elf_Data *data, struct bpf_object *obj)
+bpf_object__collect_prog_relos(struct bpf_object *obj, GElf_Shdr *shdr, Elf_Data *data)
{
Elf_Data *symbols = obj->efile.symbols;
- int text_shndx = obj->efile.text_shndx;
- int maps_shndx = obj->efile.maps_shndx;
- struct bpf_map *maps = obj->maps;
- size_t nr_maps = obj->nr_maps;
- int i, nrels;
+ const char *relo_sec_name, *sec_name;
+ size_t sec_idx = shdr->sh_info;
+ struct bpf_program *prog;
+ struct reloc_desc *relos;
+ int err, i, nrels;
+ const char *sym_name;
+ __u32 insn_idx;
+ GElf_Sym sym;
+ GElf_Rel rel;
- pr_debug("collecting relocating info for: '%s'\n",
- prog->section_name);
+ relo_sec_name = elf_sec_str(obj, shdr->sh_name);
+ sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
+ if (!relo_sec_name || !sec_name)
+ return -EINVAL;
+
+ pr_debug("sec '%s': collecting relocation for section(%zu) '%s'\n",
+ relo_sec_name, sec_idx, sec_name);
nrels = shdr->sh_size / shdr->sh_entsize;
- prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
- if (!prog->reloc_desc) {
- pr_warning("failed to alloc memory in relocation\n");
- return -ENOMEM;
- }
- prog->nr_reloc = nrels;
-
for (i = 0; i < nrels; i++) {
- GElf_Sym sym;
- GElf_Rel rel;
- unsigned int insn_idx;
- struct bpf_insn *insns = prog->insns;
- size_t map_idx;
-
if (!gelf_getrel(data, i, &rel)) {
- pr_warning("relocation: failed to get %d reloc\n", i);
+ pr_warn("sec '%s': failed to get relo #%d\n", relo_sec_name, i);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+ pr_warn("sec '%s': symbol 0x%zx not found for relo #%d\n",
+ relo_sec_name, (size_t)GELF_R_SYM(rel.r_info), i);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ if (rel.r_offset % BPF_INSN_SZ) {
+ pr_warn("sec '%s': invalid offset 0x%zx for relo #%d\n",
+ relo_sec_name, (size_t)GELF_R_SYM(rel.r_info), i);
return -LIBBPF_ERRNO__FORMAT;
}
- if (!gelf_getsym(symbols,
- GELF_R_SYM(rel.r_info),
- &sym)) {
- pr_warning("relocation: symbol %"PRIx64" not found\n",
- GELF_R_SYM(rel.r_info));
- return -LIBBPF_ERRNO__FORMAT;
- }
- pr_debug("relo for %lld value %lld name %d\n",
- (long long) (rel.r_info >> 32),
- (long long) sym.st_value, sym.st_name);
+ insn_idx = rel.r_offset / BPF_INSN_SZ;
+ /* relocations against static functions are recorded as
+ * relocations against the section that contains a function;
+ * in such case, symbol will be STT_SECTION and sym.st_name
+ * will point to empty string (0), so fetch section name
+ * instead
+ */
+ if (GELF_ST_TYPE(sym.st_info) == STT_SECTION && sym.st_name == 0)
+ sym_name = elf_sec_name(obj, elf_sec_by_idx(obj, sym.st_shndx));
+ else
+ sym_name = elf_sym_str(obj, sym.st_name);
+ sym_name = sym_name ?: "<?";
- if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) {
- pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n",
- prog->section_name, sym.st_shndx);
+ pr_debug("sec '%s': relo #%d: insn #%u against '%s'\n",
+ relo_sec_name, i, insn_idx, sym_name);
+
+ prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx);
+ if (!prog) {
+ pr_warn("sec '%s': relo #%d: program not found in section '%s' for insn #%u\n",
+ relo_sec_name, i, sec_name, insn_idx);
return -LIBBPF_ERRNO__RELOC;
}
- insn_idx = rel.r_offset / sizeof(struct bpf_insn);
- pr_debug("relocation: insn_idx=%u\n", insn_idx);
+ relos = libbpf_reallocarray(prog->reloc_desc,
+ prog->nr_reloc + 1, sizeof(*relos));
+ if (!relos)
+ return -ENOMEM;
+ prog->reloc_desc = relos;
- if (insns[insn_idx].code == (BPF_JMP | BPF_CALL)) {
- if (insns[insn_idx].src_reg != BPF_PSEUDO_CALL) {
- pr_warning("incorrect bpf_call opcode\n");
- return -LIBBPF_ERRNO__RELOC;
- }
- prog->reloc_desc[i].type = RELO_CALL;
- prog->reloc_desc[i].insn_idx = insn_idx;
- prog->reloc_desc[i].text_off = sym.st_value;
- obj->has_pseudo_calls = true;
- continue;
- }
+ /* adjust insn_idx to local BPF program frame of reference */
+ insn_idx -= prog->sec_insn_off;
+ err = bpf_program__record_reloc(prog, &relos[prog->nr_reloc],
+ insn_idx, sym_name, &sym, &rel);
+ if (err)
+ return err;
- if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
- pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
- insn_idx, insns[insn_idx].code);
- return -LIBBPF_ERRNO__RELOC;
- }
-
- /* TODO: 'maps' is sorted. We can use bsearch to make it faster. */
- for (map_idx = 0; map_idx < nr_maps; map_idx++) {
- if (maps[map_idx].offset == sym.st_value) {
- pr_debug("relocation: find map %zd (%s) for insn %u\n",
- map_idx, maps[map_idx].name, insn_idx);
- break;
- }
- }
-
- if (map_idx >= nr_maps) {
- pr_warning("bpf relocation: map_idx %d large than %d\n",
- (int)map_idx, (int)nr_maps - 1);
- return -LIBBPF_ERRNO__RELOC;
- }
-
- prog->reloc_desc[i].type = RELO_LD64;
- prog->reloc_desc[i].insn_idx = insn_idx;
- prog->reloc_desc[i].map_idx = map_idx;
+ prog->nr_reloc++;
}
return 0;
}
-static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
+static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
{
- const struct btf_type *container_type;
- const struct btf_member *key, *value;
struct bpf_map_def *def = &map->def;
- const size_t max_name = 256;
- char container_name[max_name];
- __s64 key_size, value_size;
- __s32 container_id;
+ __u32 key_type_id = 0, value_type_id = 0;
+ int ret;
- if (snprintf(container_name, max_name, "____btf_map_%s", map->name) ==
- max_name) {
- pr_warning("map:%s length of '____btf_map_%s' is too long\n",
- map->name, map->name);
- return -EINVAL;
+ /* if it's BTF-defined map, we don't need to search for type IDs.
+ * For struct_ops map, it does not need btf_key_type_id and
+ * btf_value_type_id.
+ */
+ if (map->sec_idx == obj->efile.btf_maps_shndx ||
+ bpf_map__is_struct_ops(map))
+ return 0;
+
+ if (!bpf_map__is_internal(map)) {
+ ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size,
+ def->value_size, &key_type_id,
+ &value_type_id);
+ } else {
+ /*
+ * LLVM annotates global data differently in BTF, that is,
+ * only as '.data', '.bss' or '.rodata'.
+ */
+ ret = btf__find_by_name(obj->btf,
+ libbpf_type_to_btf_name[map->libbpf_type]);
+ }
+ if (ret < 0)
+ return ret;
+
+ map->btf_key_type_id = key_type_id;
+ map->btf_value_type_id = bpf_map__is_internal(map) ?
+ ret : value_type_id;
+ return 0;
+}
+
+static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info)
+{
+ char file[PATH_MAX], buff[4096];
+ FILE *fp;
+ __u32 val;
+ int err;
+
+ snprintf(file, sizeof(file), "/proc/%d/fdinfo/%d", getpid(), fd);
+ memset(info, 0, sizeof(*info));
+
+ fp = fopen(file, "r");
+ if (!fp) {
+ err = -errno;
+ pr_warn("failed to open %s: %d. No procfs support?\n", file,
+ err);
+ return err;
}
- container_id = btf__find_by_name(btf, container_name);
- if (container_id < 0) {
- pr_debug("map:%s container_name:%s cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR?\n",
- map->name, container_name);
- return container_id;
+ while (fgets(buff, sizeof(buff), fp)) {
+ if (sscanf(buff, "map_type:\t%u", &val) == 1)
+ info->type = val;
+ else if (sscanf(buff, "key_size:\t%u", &val) == 1)
+ info->key_size = val;
+ else if (sscanf(buff, "value_size:\t%u", &val) == 1)
+ info->value_size = val;
+ else if (sscanf(buff, "max_entries:\t%u", &val) == 1)
+ info->max_entries = val;
+ else if (sscanf(buff, "map_flags:\t%i", &val) == 1)
+ info->map_flags = val;
}
- container_type = btf__type_by_id(btf, container_id);
- if (!container_type) {
- pr_warning("map:%s cannot find BTF type for container_id:%u\n",
- map->name, container_id);
- return -EINVAL;
- }
-
- if (BTF_INFO_KIND(container_type->info) != BTF_KIND_STRUCT ||
- BTF_INFO_VLEN(container_type->info) < 2) {
- pr_warning("map:%s container_name:%s is an invalid container struct\n",
- map->name, container_name);
- return -EINVAL;
- }
-
- key = (struct btf_member *)(container_type + 1);
- value = key + 1;
-
- key_size = btf__resolve_size(btf, key->type);
- if (key_size < 0) {
- pr_warning("map:%s invalid BTF key_type_size\n",
- map->name);
- return key_size;
- }
-
- if (def->key_size != key_size) {
- pr_warning("map:%s btf_key_type_size:%u != map_def_key_size:%u\n",
- map->name, (__u32)key_size, def->key_size);
- return -EINVAL;
- }
-
- value_size = btf__resolve_size(btf, value->type);
- if (value_size < 0) {
- pr_warning("map:%s invalid BTF value_type_size\n", map->name);
- return value_size;
- }
-
- if (def->value_size != value_size) {
- pr_warning("map:%s btf_value_type_size:%u != map_def_value_size:%u\n",
- map->name, (__u32)value_size, def->value_size);
- return -EINVAL;
- }
-
- map->btf_key_type_id = key->type;
- map->btf_value_type_id = value->type;
+ fclose(fp);
return 0;
}
@@ -1060,15 +3655,22 @@
int bpf_map__reuse_fd(struct bpf_map *map, int fd)
{
struct bpf_map_info info = {};
- __u32 len = sizeof(info);
+ __u32 len = sizeof(info), name_len;
int new_fd, err;
char *new_name;
err = bpf_obj_get_info_by_fd(fd, &info, &len);
+ if (err && errno == EINVAL)
+ err = bpf_get_map_info_from_fdinfo(fd, &info);
if (err)
return err;
- new_name = strdup(info.name);
+ name_len = strlen(info.name);
+ if (name_len == BPF_OBJ_NAME_LEN - 1 && strncmp(map->name, info.name, name_len) == 0)
+ new_name = strdup(map->name);
+ else
+ new_name = strdup(info.name);
+
if (!new_name)
return -errno;
@@ -1100,6 +3702,7 @@
map->def.map_flags = info.map_flags;
map->btf_key_type_id = info.btf_key_type_id;
map->btf_value_type_id = info.btf_value_type_id;
+ map->reused = true;
return 0;
@@ -1110,272 +3713,3102 @@
return err;
}
-static int
-bpf_object__create_maps(struct bpf_object *obj)
+__u32 bpf_map__max_entries(const struct bpf_map *map)
{
- struct bpf_create_map_attr create_attr = {};
- unsigned int i;
+ return map->def.max_entries;
+}
+
+int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->def.max_entries = max_entries;
+ return 0;
+}
+
+int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
+{
+ if (!map || !max_entries)
+ return -EINVAL;
+
+ return bpf_map__set_max_entries(map, max_entries);
+}
+
+static int
+bpf_object__probe_loading(struct bpf_object *obj)
+{
+ struct bpf_load_program_attr attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret;
+
+ /* make sure basic loading works */
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ attr.insns = insns;
+ attr.insns_cnt = ARRAY_SIZE(insns);
+ attr.license = "GPL";
+
+ ret = bpf_load_program_xattr(&attr, NULL, 0);
+ if (ret < 0) {
+ ret = errno;
+ cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
+ pr_warn("Error in %s():%s(%d). Couldn't load trivial BPF "
+ "program. Make sure your kernel supports BPF "
+ "(CONFIG_BPF_SYSCALL=y) and/or that RLIMIT_MEMLOCK is "
+ "set to big enough value.\n", __func__, cp, ret);
+ return -ret;
+ }
+ close(ret);
+
+ return 0;
+}
+
+static int probe_fd(int fd)
+{
+ if (fd >= 0)
+ close(fd);
+ return fd >= 0;
+}
+
+static int probe_kern_prog_name(void)
+{
+ struct bpf_load_program_attr attr;
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret;
+
+ /* make sure loading with name works */
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ attr.insns = insns;
+ attr.insns_cnt = ARRAY_SIZE(insns);
+ attr.license = "GPL";
+ attr.name = "test";
+ ret = bpf_load_program_xattr(&attr, NULL, 0);
+ return probe_fd(ret);
+}
+
+static int probe_kern_global_data(void)
+{
+ struct bpf_load_program_attr prg_attr;
+ struct bpf_create_map_attr map_attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
+ BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret, map;
+
+ memset(&map_attr, 0, sizeof(map_attr));
+ map_attr.map_type = BPF_MAP_TYPE_ARRAY;
+ map_attr.key_size = sizeof(int);
+ map_attr.value_size = 32;
+ map_attr.max_entries = 1;
+
+ map = bpf_create_map_xattr(&map_attr);
+ if (map < 0) {
+ ret = -errno;
+ cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
+ pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
+ __func__, cp, -ret);
+ return ret;
+ }
+
+ insns[0].imm = map;
+
+ memset(&prg_attr, 0, sizeof(prg_attr));
+ prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ prg_attr.insns = insns;
+ prg_attr.insns_cnt = ARRAY_SIZE(insns);
+ prg_attr.license = "GPL";
+
+ ret = bpf_load_program_xattr(&prg_attr, NULL, 0);
+ close(map);
+ return probe_fd(ret);
+}
+
+static int probe_kern_btf(void)
+{
+ static const char strs[] = "\0int";
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs)));
+}
+
+static int probe_kern_btf_func(void)
+{
+ static const char strs[] = "\0int\0x\0a";
+ /* void x(int a) {} */
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* FUNC_PROTO */ /* [2] */
+ BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
+ BTF_PARAM_ENC(7, 1),
+ /* FUNC x */ /* [3] */
+ BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs)));
+}
+
+static int probe_kern_btf_func_global(void)
+{
+ static const char strs[] = "\0int\0x\0a";
+ /* static void x(int a) {} */
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* FUNC_PROTO */ /* [2] */
+ BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
+ BTF_PARAM_ENC(7, 1),
+ /* FUNC x BTF_FUNC_GLOBAL */ /* [3] */
+ BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, BTF_FUNC_GLOBAL), 2),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs)));
+}
+
+static int probe_kern_btf_datasec(void)
+{
+ static const char strs[] = "\0x\0.data";
+ /* static int a; */
+ __u32 types[] = {
+ /* int */
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ /* VAR x */ /* [2] */
+ BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+ BTF_VAR_STATIC,
+ /* DATASEC val */ /* [3] */
+ BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+ BTF_VAR_SECINFO_ENC(2, 0, 4),
+ };
+
+ return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+ strs, sizeof(strs)));
+}
+
+static int probe_kern_array_mmap(void)
+{
+ struct bpf_create_map_attr attr = {
+ .map_type = BPF_MAP_TYPE_ARRAY,
+ .map_flags = BPF_F_MMAPABLE,
+ .key_size = sizeof(int),
+ .value_size = sizeof(int),
+ .max_entries = 1,
+ };
+
+ return probe_fd(bpf_create_map_xattr(&attr));
+}
+
+static int probe_kern_exp_attach_type(void)
+{
+ struct bpf_load_program_attr attr;
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+
+ memset(&attr, 0, sizeof(attr));
+ /* use any valid combination of program type and (optional)
+ * non-zero expected attach type (i.e., not a BPF_CGROUP_INET_INGRESS)
+ * to see if kernel supports expected_attach_type field for
+ * BPF_PROG_LOAD command
+ */
+ attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
+ attr.expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE;
+ attr.insns = insns;
+ attr.insns_cnt = ARRAY_SIZE(insns);
+ attr.license = "GPL";
+
+ return probe_fd(bpf_load_program_xattr(&attr, NULL, 0));
+}
+
+static int probe_kern_probe_read_kernel(void)
+{
+ struct bpf_load_program_attr attr;
+ struct bpf_insn insns[] = {
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), /* r1 = r10 (fp) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), /* r1 += -8 */
+ BPF_MOV64_IMM(BPF_REG_2, 8), /* r2 = 8 */
+ BPF_MOV64_IMM(BPF_REG_3, 0), /* r3 = 0 */
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_probe_read_kernel),
+ BPF_EXIT_INSN(),
+ };
+
+ memset(&attr, 0, sizeof(attr));
+ attr.prog_type = BPF_PROG_TYPE_KPROBE;
+ attr.insns = insns;
+ attr.insns_cnt = ARRAY_SIZE(insns);
+ attr.license = "GPL";
+
+ return probe_fd(bpf_load_program_xattr(&attr, NULL, 0));
+}
+
+static int probe_prog_bind_map(void)
+{
+ struct bpf_load_program_attr prg_attr;
+ struct bpf_create_map_attr map_attr;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ struct bpf_insn insns[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ };
+ int ret, map, prog;
+
+ memset(&map_attr, 0, sizeof(map_attr));
+ map_attr.map_type = BPF_MAP_TYPE_ARRAY;
+ map_attr.key_size = sizeof(int);
+ map_attr.value_size = 32;
+ map_attr.max_entries = 1;
+
+ map = bpf_create_map_xattr(&map_attr);
+ if (map < 0) {
+ ret = -errno;
+ cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));
+ pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
+ __func__, cp, -ret);
+ return ret;
+ }
+
+ memset(&prg_attr, 0, sizeof(prg_attr));
+ prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
+ prg_attr.insns = insns;
+ prg_attr.insns_cnt = ARRAY_SIZE(insns);
+ prg_attr.license = "GPL";
+
+ prog = bpf_load_program_xattr(&prg_attr, NULL, 0);
+ if (prog < 0) {
+ close(map);
+ return 0;
+ }
+
+ ret = bpf_prog_bind_map(prog, map, NULL);
+
+ close(map);
+ close(prog);
+
+ return ret >= 0;
+}
+
+enum kern_feature_result {
+ FEAT_UNKNOWN = 0,
+ FEAT_SUPPORTED = 1,
+ FEAT_MISSING = 2,
+};
+
+typedef int (*feature_probe_fn)(void);
+
+static struct kern_feature_desc {
+ const char *desc;
+ feature_probe_fn probe;
+ enum kern_feature_result res;
+} feature_probes[__FEAT_CNT] = {
+ [FEAT_PROG_NAME] = {
+ "BPF program name", probe_kern_prog_name,
+ },
+ [FEAT_GLOBAL_DATA] = {
+ "global variables", probe_kern_global_data,
+ },
+ [FEAT_BTF] = {
+ "minimal BTF", probe_kern_btf,
+ },
+ [FEAT_BTF_FUNC] = {
+ "BTF functions", probe_kern_btf_func,
+ },
+ [FEAT_BTF_GLOBAL_FUNC] = {
+ "BTF global function", probe_kern_btf_func_global,
+ },
+ [FEAT_BTF_DATASEC] = {
+ "BTF data section and variable", probe_kern_btf_datasec,
+ },
+ [FEAT_ARRAY_MMAP] = {
+ "ARRAY map mmap()", probe_kern_array_mmap,
+ },
+ [FEAT_EXP_ATTACH_TYPE] = {
+ "BPF_PROG_LOAD expected_attach_type attribute",
+ probe_kern_exp_attach_type,
+ },
+ [FEAT_PROBE_READ_KERN] = {
+ "bpf_probe_read_kernel() helper", probe_kern_probe_read_kernel,
+ },
+ [FEAT_PROG_BIND_MAP] = {
+ "BPF_PROG_BIND_MAP support", probe_prog_bind_map,
+ }
+};
+
+static bool kernel_supports(enum kern_feature_id feat_id)
+{
+ struct kern_feature_desc *feat = &feature_probes[feat_id];
+ int ret;
+
+ if (READ_ONCE(feat->res) == FEAT_UNKNOWN) {
+ ret = feat->probe();
+ if (ret > 0) {
+ WRITE_ONCE(feat->res, FEAT_SUPPORTED);
+ } else if (ret == 0) {
+ WRITE_ONCE(feat->res, FEAT_MISSING);
+ } else {
+ pr_warn("Detection of kernel %s support failed: %d\n", feat->desc, ret);
+ WRITE_ONCE(feat->res, FEAT_MISSING);
+ }
+ }
+
+ return READ_ONCE(feat->res) == FEAT_SUPPORTED;
+}
+
+static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
+{
+ struct bpf_map_info map_info = {};
+ char msg[STRERR_BUFSIZE];
+ __u32 map_info_len;
int err;
- for (i = 0; i < obj->nr_maps; i++) {
- struct bpf_map *map = &obj->maps[i];
- struct bpf_map_def *def = &map->def;
- char *cp, errmsg[STRERR_BUFSIZE];
- int *pfd = &map->fd;
+ map_info_len = sizeof(map_info);
- if (map->fd >= 0) {
- pr_debug("skip map create (preset) %s: fd=%d\n",
- map->name, map->fd);
- continue;
+ err = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len);
+ if (err && errno == EINVAL)
+ err = bpf_get_map_info_from_fdinfo(map_fd, &map_info);
+ if (err) {
+ pr_warn("failed to get map info for map FD %d: %s\n", map_fd,
+ libbpf_strerror_r(errno, msg, sizeof(msg)));
+ return false;
+ }
+
+ return (map_info.type == map->def.type &&
+ map_info.key_size == map->def.key_size &&
+ map_info.value_size == map->def.value_size &&
+ map_info.max_entries == map->def.max_entries &&
+ map_info.map_flags == map->def.map_flags);
+}
+
+static int
+bpf_object__reuse_map(struct bpf_map *map)
+{
+ char *cp, errmsg[STRERR_BUFSIZE];
+ int err, pin_fd;
+
+ pin_fd = bpf_obj_get(map->pin_path);
+ if (pin_fd < 0) {
+ err = -errno;
+ if (err == -ENOENT) {
+ pr_debug("found no pinned map to reuse at '%s'\n",
+ map->pin_path);
+ return 0;
}
+ cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
+ pr_warn("couldn't retrieve pinned map '%s': %s\n",
+ map->pin_path, cp);
+ return err;
+ }
+
+ if (!map_is_reuse_compat(map, pin_fd)) {
+ pr_warn("couldn't reuse pinned map at '%s': parameter mismatch\n",
+ map->pin_path);
+ close(pin_fd);
+ return -EINVAL;
+ }
+
+ err = bpf_map__reuse_fd(map, pin_fd);
+ if (err) {
+ close(pin_fd);
+ return err;
+ }
+ map->pinned = true;
+ pr_debug("reused pinned map at '%s'\n", map->pin_path);
+
+ return 0;
+}
+
+static int
+bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
+{
+ enum libbpf_map_type map_type = map->libbpf_type;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ int err, zero = 0;
+
+ err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0);
+ if (err) {
+ err = -errno;
+ cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+ pr_warn("Error setting initial map(%s) contents: %s\n",
+ map->name, cp);
+ return err;
+ }
+
+ /* Freeze .rodata and .kconfig map as read-only from syscall side. */
+ if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG) {
+ err = bpf_map_freeze(map->fd);
+ if (err) {
+ err = -errno;
+ cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+ pr_warn("Error freezing map(%s) as read-only: %s\n",
+ map->name, cp);
+ return err;
+ }
+ }
+ return 0;
+}
+
+static void bpf_map__destroy(struct bpf_map *map);
+
+static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
+{
+ struct bpf_create_map_attr create_attr;
+ struct bpf_map_def *def = &map->def;
+ int err = 0;
+
+ memset(&create_attr, 0, sizeof(create_attr));
+
+ if (kernel_supports(FEAT_PROG_NAME))
create_attr.name = map->name;
- create_attr.map_ifindex = map->map_ifindex;
- create_attr.map_type = def->type;
- create_attr.map_flags = def->map_flags;
- create_attr.key_size = def->key_size;
- create_attr.value_size = def->value_size;
+ create_attr.map_ifindex = map->map_ifindex;
+ create_attr.map_type = def->type;
+ create_attr.map_flags = def->map_flags;
+ create_attr.key_size = def->key_size;
+ create_attr.value_size = def->value_size;
+ create_attr.numa_node = map->numa_node;
+
+ if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !def->max_entries) {
+ int nr_cpus;
+
+ nr_cpus = libbpf_num_possible_cpus();
+ if (nr_cpus < 0) {
+ pr_warn("map '%s': failed to determine number of system CPUs: %d\n",
+ map->name, nr_cpus);
+ return nr_cpus;
+ }
+ pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus);
+ create_attr.max_entries = nr_cpus;
+ } else {
create_attr.max_entries = def->max_entries;
+ }
+
+ if (bpf_map__is_struct_ops(map))
+ create_attr.btf_vmlinux_value_type_id =
+ map->btf_vmlinux_value_type_id;
+
+ create_attr.btf_fd = 0;
+ create_attr.btf_key_type_id = 0;
+ create_attr.btf_value_type_id = 0;
+ if (obj->btf && btf__fd(obj->btf) >= 0 && !bpf_map_find_btf_info(obj, map)) {
+ create_attr.btf_fd = btf__fd(obj->btf);
+ create_attr.btf_key_type_id = map->btf_key_type_id;
+ create_attr.btf_value_type_id = map->btf_value_type_id;
+ }
+
+ if (bpf_map_type__is_map_in_map(def->type)) {
+ if (map->inner_map) {
+ err = bpf_object__create_map(obj, map->inner_map);
+ if (err) {
+ pr_warn("map '%s': failed to create inner map: %d\n",
+ map->name, err);
+ return err;
+ }
+ map->inner_map_fd = bpf_map__fd(map->inner_map);
+ }
+ if (map->inner_map_fd >= 0)
+ create_attr.inner_map_fd = map->inner_map_fd;
+ }
+
+ map->fd = bpf_create_map_xattr(&create_attr);
+ if (map->fd < 0 && (create_attr.btf_key_type_id ||
+ create_attr.btf_value_type_id)) {
+ char *cp, errmsg[STRERR_BUFSIZE];
+
+ err = -errno;
+ cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+ pr_warn("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
+ map->name, cp, err);
create_attr.btf_fd = 0;
create_attr.btf_key_type_id = 0;
create_attr.btf_value_type_id = 0;
+ map->btf_key_type_id = 0;
+ map->btf_value_type_id = 0;
+ map->fd = bpf_create_map_xattr(&create_attr);
+ }
- if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) {
- create_attr.btf_fd = btf__fd(obj->btf);
- create_attr.btf_key_type_id = map->btf_key_type_id;
- create_attr.btf_value_type_id = map->btf_value_type_id;
- }
+ err = map->fd < 0 ? -errno : 0;
- *pfd = bpf_create_map_xattr(&create_attr);
- if (*pfd < 0 && create_attr.btf_key_type_id) {
- cp = str_error(errno, errmsg, sizeof(errmsg));
- pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
- map->name, cp, errno);
- create_attr.btf_fd = 0;
- create_attr.btf_key_type_id = 0;
- create_attr.btf_value_type_id = 0;
- map->btf_key_type_id = 0;
- map->btf_value_type_id = 0;
- *pfd = bpf_create_map_xattr(&create_attr);
- }
+ if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) {
+ bpf_map__destroy(map->inner_map);
+ zfree(&map->inner_map);
+ }
- if (*pfd < 0) {
- size_t j;
+ return err;
+}
- err = *pfd;
- cp = str_error(errno, errmsg, sizeof(errmsg));
- pr_warning("failed to create map (name: '%s'): %s\n",
- map->name, cp);
- for (j = 0; j < i; j++)
- zclose(obj->maps[j].fd);
+static int init_map_slots(struct bpf_map *map)
+{
+ const struct bpf_map *targ_map;
+ unsigned int i;
+ int fd, err;
+
+ for (i = 0; i < map->init_slots_sz; i++) {
+ if (!map->init_slots[i])
+ continue;
+
+ targ_map = map->init_slots[i];
+ fd = bpf_map__fd(targ_map);
+ err = bpf_map_update_elem(map->fd, &i, &fd, 0);
+ if (err) {
+ err = -errno;
+ pr_warn("map '%s': failed to initialize slot [%d] to map '%s' fd=%d: %d\n",
+ map->name, i, targ_map->name,
+ fd, err);
return err;
}
- pr_debug("create map %s: fd=%d\n", map->name, *pfd);
+ pr_debug("map '%s': slot [%d] set to map '%s' fd=%d\n",
+ map->name, i, targ_map->name, fd);
}
+
+ zfree(&map->init_slots);
+ map->init_slots_sz = 0;
return 0;
}
static int
-bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
- struct reloc_desc *relo)
+bpf_object__create_maps(struct bpf_object *obj)
{
- struct bpf_insn *insn, *new_insn;
- struct bpf_program *text;
- size_t new_cnt;
+ struct bpf_map *map;
+ char *cp, errmsg[STRERR_BUFSIZE];
+ unsigned int i, j;
+ int err;
+ bool retried;
- if (relo->type != RELO_CALL)
- return -LIBBPF_ERRNO__RELOC;
+ for (i = 0; i < obj->nr_maps; i++) {
+ map = &obj->maps[i];
- if (prog->idx == obj->efile.text_shndx) {
- pr_warning("relo in .text insn %d into off %d\n",
- relo->insn_idx, relo->text_off);
- return -LIBBPF_ERRNO__RELOC;
+ retried = false;
+retry:
+ if (map->pin_path) {
+ err = bpf_object__reuse_map(map);
+ if (err) {
+ pr_warn("map '%s': error reusing pinned map\n",
+ map->name);
+ goto err_out;
+ }
+ if (retried && map->fd < 0) {
+ pr_warn("map '%s': cannot find pinned map\n",
+ map->name);
+ err = -ENOENT;
+ goto err_out;
+ }
+ }
+
+ if (map->fd >= 0) {
+ pr_debug("map '%s': skipping creation (preset fd=%d)\n",
+ map->name, map->fd);
+ } else {
+ err = bpf_object__create_map(obj, map);
+ if (err)
+ goto err_out;
+
+ pr_debug("map '%s': created successfully, fd=%d\n",
+ map->name, map->fd);
+
+ if (bpf_map__is_internal(map)) {
+ err = bpf_object__populate_internal_map(obj, map);
+ if (err < 0) {
+ zclose(map->fd);
+ goto err_out;
+ }
+ }
+
+ if (map->init_slots_sz) {
+ err = init_map_slots(map);
+ if (err < 0) {
+ zclose(map->fd);
+ goto err_out;
+ }
+ }
+ }
+
+ if (map->pin_path && !map->pinned) {
+ err = bpf_map__pin(map, NULL);
+ if (err) {
+ zclose(map->fd);
+ if (!retried && err == -EEXIST) {
+ retried = true;
+ goto retry;
+ }
+ pr_warn("map '%s': failed to auto-pin at '%s': %d\n",
+ map->name, map->pin_path, err);
+ goto err_out;
+ }
+ }
}
- if (prog->main_prog_cnt == 0) {
- text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx);
- if (!text) {
- pr_warning("no .text section found yet relo into text exist\n");
- return -LIBBPF_ERRNO__RELOC;
- }
- new_cnt = prog->insns_cnt + text->insns_cnt;
- new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
- if (!new_insn) {
- pr_warning("oom in prog realloc\n");
- return -ENOMEM;
- }
- memcpy(new_insn + prog->insns_cnt, text->insns,
- text->insns_cnt * sizeof(*insn));
- prog->insns = new_insn;
- prog->main_prog_cnt = prog->insns_cnt;
- prog->insns_cnt = new_cnt;
- pr_debug("added %zd insn from %s to prog %s\n",
- text->insns_cnt, text->section_name,
- prog->section_name);
+ return 0;
+
+err_out:
+ cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+ pr_warn("map '%s': failed to create: %s(%d)\n", map->name, cp, err);
+ pr_perm_msg(err);
+ for (j = 0; j < i; j++)
+ zclose(obj->maps[j].fd);
+ return err;
+}
+
+#define BPF_CORE_SPEC_MAX_LEN 64
+
+/* represents BPF CO-RE field or array element accessor */
+struct bpf_core_accessor {
+ __u32 type_id; /* struct/union type or array element type */
+ __u32 idx; /* field index or array index */
+ const char *name; /* field name or NULL for array accessor */
+};
+
+struct bpf_core_spec {
+ const struct btf *btf;
+ /* high-level spec: named fields and array indices only */
+ struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];
+ /* original unresolved (no skip_mods_or_typedefs) root type ID */
+ __u32 root_type_id;
+ /* CO-RE relocation kind */
+ enum bpf_core_relo_kind relo_kind;
+ /* high-level spec length */
+ int len;
+ /* raw, low-level spec: 1-to-1 with accessor spec string */
+ int raw_spec[BPF_CORE_SPEC_MAX_LEN];
+ /* raw spec length */
+ int raw_len;
+ /* field bit offset represented by spec */
+ __u32 bit_offset;
+};
+
+static bool str_is_empty(const char *s)
+{
+ return !s || !s[0];
+}
+
+static bool is_flex_arr(const struct btf *btf,
+ const struct bpf_core_accessor *acc,
+ const struct btf_array *arr)
+{
+ const struct btf_type *t;
+
+ /* not a flexible array, if not inside a struct or has non-zero size */
+ if (!acc->name || arr->nelems > 0)
+ return false;
+
+ /* has to be the last member of enclosing struct */
+ t = btf__type_by_id(btf, acc->type_id);
+ return acc->idx == btf_vlen(t) - 1;
+}
+
+static const char *core_relo_kind_str(enum bpf_core_relo_kind kind)
+{
+ switch (kind) {
+ case BPF_FIELD_BYTE_OFFSET: return "byte_off";
+ case BPF_FIELD_BYTE_SIZE: return "byte_sz";
+ case BPF_FIELD_EXISTS: return "field_exists";
+ case BPF_FIELD_SIGNED: return "signed";
+ case BPF_FIELD_LSHIFT_U64: return "lshift_u64";
+ case BPF_FIELD_RSHIFT_U64: return "rshift_u64";
+ case BPF_TYPE_ID_LOCAL: return "local_type_id";
+ case BPF_TYPE_ID_TARGET: return "target_type_id";
+ case BPF_TYPE_EXISTS: return "type_exists";
+ case BPF_TYPE_SIZE: return "type_size";
+ case BPF_ENUMVAL_EXISTS: return "enumval_exists";
+ case BPF_ENUMVAL_VALUE: return "enumval_value";
+ default: return "unknown";
}
- insn = &prog->insns[relo->insn_idx];
- insn->imm += prog->main_prog_cnt - relo->insn_idx;
+}
+
+static bool core_relo_is_field_based(enum bpf_core_relo_kind kind)
+{
+ switch (kind) {
+ case BPF_FIELD_BYTE_OFFSET:
+ case BPF_FIELD_BYTE_SIZE:
+ case BPF_FIELD_EXISTS:
+ case BPF_FIELD_SIGNED:
+ case BPF_FIELD_LSHIFT_U64:
+ case BPF_FIELD_RSHIFT_U64:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool core_relo_is_type_based(enum bpf_core_relo_kind kind)
+{
+ switch (kind) {
+ case BPF_TYPE_ID_LOCAL:
+ case BPF_TYPE_ID_TARGET:
+ case BPF_TYPE_EXISTS:
+ case BPF_TYPE_SIZE:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool core_relo_is_enumval_based(enum bpf_core_relo_kind kind)
+{
+ switch (kind) {
+ case BPF_ENUMVAL_EXISTS:
+ case BPF_ENUMVAL_VALUE:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/*
+ * Turn bpf_core_relo into a low- and high-level spec representation,
+ * validating correctness along the way, as well as calculating resulting
+ * field bit offset, specified by accessor string. Low-level spec captures
+ * every single level of nestedness, including traversing anonymous
+ * struct/union members. High-level one only captures semantically meaningful
+ * "turning points": named fields and array indicies.
+ * E.g., for this case:
+ *
+ * struct sample {
+ * int __unimportant;
+ * struct {
+ * int __1;
+ * int __2;
+ * int a[7];
+ * };
+ * };
+ *
+ * struct sample *s = ...;
+ *
+ * int x = &s->a[3]; // access string = '0:1:2:3'
+ *
+ * Low-level spec has 1:1 mapping with each element of access string (it's
+ * just a parsed access string representation): [0, 1, 2, 3].
+ *
+ * High-level spec will capture only 3 points:
+ * - intial zero-index access by pointer (&s->... is the same as &s[0]...);
+ * - field 'a' access (corresponds to '2' in low-level spec);
+ * - array element #3 access (corresponds to '3' in low-level spec).
+ *
+ * Type-based relocations (TYPE_EXISTS/TYPE_SIZE,
+ * TYPE_ID_LOCAL/TYPE_ID_TARGET) don't capture any field information. Their
+ * spec and raw_spec are kept empty.
+ *
+ * Enum value-based relocations (ENUMVAL_EXISTS/ENUMVAL_VALUE) use access
+ * string to specify enumerator's value index that need to be relocated.
+ */
+static int bpf_core_parse_spec(const struct btf *btf,
+ __u32 type_id,
+ const char *spec_str,
+ enum bpf_core_relo_kind relo_kind,
+ struct bpf_core_spec *spec)
+{
+ int access_idx, parsed_len, i;
+ struct bpf_core_accessor *acc;
+ const struct btf_type *t;
+ const char *name;
+ __u32 id;
+ __s64 sz;
+
+ if (str_is_empty(spec_str) || *spec_str == ':')
+ return -EINVAL;
+
+ memset(spec, 0, sizeof(*spec));
+ spec->btf = btf;
+ spec->root_type_id = type_id;
+ spec->relo_kind = relo_kind;
+
+ /* type-based relocations don't have a field access string */
+ if (core_relo_is_type_based(relo_kind)) {
+ if (strcmp(spec_str, "0"))
+ return -EINVAL;
+ return 0;
+ }
+
+ /* parse spec_str="0:1:2:3:4" into array raw_spec=[0, 1, 2, 3, 4] */
+ while (*spec_str) {
+ if (*spec_str == ':')
+ ++spec_str;
+ if (sscanf(spec_str, "%d%n", &access_idx, &parsed_len) != 1)
+ return -EINVAL;
+ if (spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
+ return -E2BIG;
+ spec_str += parsed_len;
+ spec->raw_spec[spec->raw_len++] = access_idx;
+ }
+
+ if (spec->raw_len == 0)
+ return -EINVAL;
+
+ t = skip_mods_and_typedefs(btf, type_id, &id);
+ if (!t)
+ return -EINVAL;
+
+ access_idx = spec->raw_spec[0];
+ acc = &spec->spec[0];
+ acc->type_id = id;
+ acc->idx = access_idx;
+ spec->len++;
+
+ if (core_relo_is_enumval_based(relo_kind)) {
+ if (!btf_is_enum(t) || spec->raw_len > 1 || access_idx >= btf_vlen(t))
+ return -EINVAL;
+
+ /* record enumerator name in a first accessor */
+ acc->name = btf__name_by_offset(btf, btf_enum(t)[access_idx].name_off);
+ return 0;
+ }
+
+ if (!core_relo_is_field_based(relo_kind))
+ return -EINVAL;
+
+ sz = btf__resolve_size(btf, id);
+ if (sz < 0)
+ return sz;
+ spec->bit_offset = access_idx * sz * 8;
+
+ for (i = 1; i < spec->raw_len; i++) {
+ t = skip_mods_and_typedefs(btf, id, &id);
+ if (!t)
+ return -EINVAL;
+
+ access_idx = spec->raw_spec[i];
+ acc = &spec->spec[spec->len];
+
+ if (btf_is_composite(t)) {
+ const struct btf_member *m;
+ __u32 bit_offset;
+
+ if (access_idx >= btf_vlen(t))
+ return -EINVAL;
+
+ bit_offset = btf_member_bit_offset(t, access_idx);
+ spec->bit_offset += bit_offset;
+
+ m = btf_members(t) + access_idx;
+ if (m->name_off) {
+ name = btf__name_by_offset(btf, m->name_off);
+ if (str_is_empty(name))
+ return -EINVAL;
+
+ acc->type_id = id;
+ acc->idx = access_idx;
+ acc->name = name;
+ spec->len++;
+ }
+
+ id = m->type;
+ } else if (btf_is_array(t)) {
+ const struct btf_array *a = btf_array(t);
+ bool flex;
+
+ t = skip_mods_and_typedefs(btf, a->type, &id);
+ if (!t)
+ return -EINVAL;
+
+ flex = is_flex_arr(btf, acc - 1, a);
+ if (!flex && access_idx >= a->nelems)
+ return -EINVAL;
+
+ spec->spec[spec->len].type_id = id;
+ spec->spec[spec->len].idx = access_idx;
+ spec->len++;
+
+ sz = btf__resolve_size(btf, id);
+ if (sz < 0)
+ return sz;
+ spec->bit_offset += access_idx * sz * 8;
+ } else {
+ pr_warn("relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %s\n",
+ type_id, spec_str, i, id, btf_kind_str(t));
+ return -EINVAL;
+ }
+ }
+
return 0;
}
-static int
-bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
+static bool bpf_core_is_flavor_sep(const char *s)
{
- int i, err;
+ /* check X___Y name pattern, where X and Y are not underscores */
+ return s[0] != '_' && /* X */
+ s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */
+ s[4] != '_'; /* Y */
+}
- if (!prog || !prog->reloc_desc)
+/* Given 'some_struct_name___with_flavor' return the length of a name prefix
+ * before last triple underscore. Struct name part after last triple
+ * underscore is ignored by BPF CO-RE relocation during relocation matching.
+ */
+static size_t bpf_core_essential_name_len(const char *name)
+{
+ size_t n = strlen(name);
+ int i;
+
+ for (i = n - 5; i >= 0; i--) {
+ if (bpf_core_is_flavor_sep(name + i))
+ return i + 1;
+ }
+ return n;
+}
+
+/* dynamically sized list of type IDs */
+struct ids_vec {
+ __u32 *data;
+ int len;
+};
+
+static void bpf_core_free_cands(struct ids_vec *cand_ids)
+{
+ free(cand_ids->data);
+ free(cand_ids);
+}
+
+static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
+ __u32 local_type_id,
+ const struct btf *targ_btf)
+{
+ size_t local_essent_len, targ_essent_len;
+ const char *local_name, *targ_name;
+ const struct btf_type *t, *local_t;
+ struct ids_vec *cand_ids;
+ __u32 *new_ids;
+ int i, err, n;
+
+ local_t = btf__type_by_id(local_btf, local_type_id);
+ if (!local_t)
+ return ERR_PTR(-EINVAL);
+
+ local_name = btf__name_by_offset(local_btf, local_t->name_off);
+ if (str_is_empty(local_name))
+ return ERR_PTR(-EINVAL);
+ local_essent_len = bpf_core_essential_name_len(local_name);
+
+ cand_ids = calloc(1, sizeof(*cand_ids));
+ if (!cand_ids)
+ return ERR_PTR(-ENOMEM);
+
+ n = btf__get_nr_types(targ_btf);
+ for (i = 1; i <= n; i++) {
+ t = btf__type_by_id(targ_btf, i);
+ if (btf_kind(t) != btf_kind(local_t))
+ continue;
+
+ targ_name = btf__name_by_offset(targ_btf, t->name_off);
+ if (str_is_empty(targ_name))
+ continue;
+
+ targ_essent_len = bpf_core_essential_name_len(targ_name);
+ if (targ_essent_len != local_essent_len)
+ continue;
+
+ if (strncmp(local_name, targ_name, local_essent_len) == 0) {
+ pr_debug("CO-RE relocating [%d] %s %s: found target candidate [%d] %s %s\n",
+ local_type_id, btf_kind_str(local_t),
+ local_name, i, btf_kind_str(t), targ_name);
+ new_ids = libbpf_reallocarray(cand_ids->data,
+ cand_ids->len + 1,
+ sizeof(*cand_ids->data));
+ if (!new_ids) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ cand_ids->data = new_ids;
+ cand_ids->data[cand_ids->len++] = i;
+ }
+ }
+ return cand_ids;
+err_out:
+ bpf_core_free_cands(cand_ids);
+ return ERR_PTR(err);
+}
+
+/* Check two types for compatibility for the purpose of field access
+ * relocation. const/volatile/restrict and typedefs are skipped to ensure we
+ * are relocating semantically compatible entities:
+ * - any two STRUCTs/UNIONs are compatible and can be mixed;
+ * - any two FWDs are compatible, if their names match (modulo flavor suffix);
+ * - any two PTRs are always compatible;
+ * - for ENUMs, names should be the same (ignoring flavor suffix) or at
+ * least one of enums should be anonymous;
+ * - for ENUMs, check sizes, names are ignored;
+ * - for INT, size and signedness are ignored;
+ * - for ARRAY, dimensionality is ignored, element types are checked for
+ * compatibility recursively;
+ * - everything else shouldn't be ever a target of relocation.
+ * These rules are not set in stone and probably will be adjusted as we get
+ * more experience with using BPF CO-RE relocations.
+ */
+static int bpf_core_fields_are_compat(const struct btf *local_btf,
+ __u32 local_id,
+ const struct btf *targ_btf,
+ __u32 targ_id)
+{
+ const struct btf_type *local_type, *targ_type;
+
+recur:
+ local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id);
+ targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
+ if (!local_type || !targ_type)
+ return -EINVAL;
+
+ if (btf_is_composite(local_type) && btf_is_composite(targ_type))
+ return 1;
+ if (btf_kind(local_type) != btf_kind(targ_type))
return 0;
- for (i = 0; i < prog->nr_reloc; i++) {
- if (prog->reloc_desc[i].type == RELO_LD64) {
- struct bpf_insn *insns = prog->insns;
- int insn_idx, map_idx;
+ switch (btf_kind(local_type)) {
+ case BTF_KIND_PTR:
+ return 1;
+ case BTF_KIND_FWD:
+ case BTF_KIND_ENUM: {
+ const char *local_name, *targ_name;
+ size_t local_len, targ_len;
- insn_idx = prog->reloc_desc[i].insn_idx;
- map_idx = prog->reloc_desc[i].map_idx;
+ local_name = btf__name_by_offset(local_btf,
+ local_type->name_off);
+ targ_name = btf__name_by_offset(targ_btf, targ_type->name_off);
+ local_len = bpf_core_essential_name_len(local_name);
+ targ_len = bpf_core_essential_name_len(targ_name);
+ /* one of them is anonymous or both w/ same flavor-less names */
+ return local_len == 0 || targ_len == 0 ||
+ (local_len == targ_len &&
+ strncmp(local_name, targ_name, local_len) == 0);
+ }
+ case BTF_KIND_INT:
+ /* just reject deprecated bitfield-like integers; all other
+ * integers are by default compatible between each other
+ */
+ return btf_int_offset(local_type) == 0 &&
+ btf_int_offset(targ_type) == 0;
+ case BTF_KIND_ARRAY:
+ local_id = btf_array(local_type)->type;
+ targ_id = btf_array(targ_type)->type;
+ goto recur;
+ default:
+ pr_warn("unexpected kind %d relocated, local [%d], target [%d]\n",
+ btf_kind(local_type), local_id, targ_id);
+ return 0;
+ }
+}
- if (insn_idx >= (int)prog->insns_cnt) {
- pr_warning("relocation out of range: '%s'\n",
- prog->section_name);
- return -LIBBPF_ERRNO__RELOC;
+/*
+ * Given single high-level named field accessor in local type, find
+ * corresponding high-level accessor for a target type. Along the way,
+ * maintain low-level spec for target as well. Also keep updating target
+ * bit offset.
+ *
+ * Searching is performed through recursive exhaustive enumeration of all
+ * fields of a struct/union. If there are any anonymous (embedded)
+ * structs/unions, they are recursively searched as well. If field with
+ * desired name is found, check compatibility between local and target types,
+ * before returning result.
+ *
+ * 1 is returned, if field is found.
+ * 0 is returned if no compatible field is found.
+ * <0 is returned on error.
+ */
+static int bpf_core_match_member(const struct btf *local_btf,
+ const struct bpf_core_accessor *local_acc,
+ const struct btf *targ_btf,
+ __u32 targ_id,
+ struct bpf_core_spec *spec,
+ __u32 *next_targ_id)
+{
+ const struct btf_type *local_type, *targ_type;
+ const struct btf_member *local_member, *m;
+ const char *local_name, *targ_name;
+ __u32 local_id;
+ int i, n, found;
+
+ targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
+ if (!targ_type)
+ return -EINVAL;
+ if (!btf_is_composite(targ_type))
+ return 0;
+
+ local_id = local_acc->type_id;
+ local_type = btf__type_by_id(local_btf, local_id);
+ local_member = btf_members(local_type) + local_acc->idx;
+ local_name = btf__name_by_offset(local_btf, local_member->name_off);
+
+ n = btf_vlen(targ_type);
+ m = btf_members(targ_type);
+ for (i = 0; i < n; i++, m++) {
+ __u32 bit_offset;
+
+ bit_offset = btf_member_bit_offset(targ_type, i);
+
+ /* too deep struct/union/array nesting */
+ if (spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
+ return -E2BIG;
+
+ /* speculate this member will be the good one */
+ spec->bit_offset += bit_offset;
+ spec->raw_spec[spec->raw_len++] = i;
+
+ targ_name = btf__name_by_offset(targ_btf, m->name_off);
+ if (str_is_empty(targ_name)) {
+ /* embedded struct/union, we need to go deeper */
+ found = bpf_core_match_member(local_btf, local_acc,
+ targ_btf, m->type,
+ spec, next_targ_id);
+ if (found) /* either found or error */
+ return found;
+ } else if (strcmp(local_name, targ_name) == 0) {
+ /* matching named field */
+ struct bpf_core_accessor *targ_acc;
+
+ targ_acc = &spec->spec[spec->len++];
+ targ_acc->type_id = targ_id;
+ targ_acc->idx = i;
+ targ_acc->name = targ_name;
+
+ *next_targ_id = m->type;
+ found = bpf_core_fields_are_compat(local_btf,
+ local_member->type,
+ targ_btf, m->type);
+ if (!found)
+ spec->len--; /* pop accessor */
+ return found;
+ }
+ /* member turned out not to be what we looked for */
+ spec->bit_offset -= bit_offset;
+ spec->raw_len--;
+ }
+
+ return 0;
+}
+
+/* Check local and target types for compatibility. This check is used for
+ * type-based CO-RE relocations and follow slightly different rules than
+ * field-based relocations. This function assumes that root types were already
+ * checked for name match. Beyond that initial root-level name check, names
+ * are completely ignored. Compatibility rules are as follows:
+ * - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs are considered compatible, but
+ * kind should match for local and target types (i.e., STRUCT is not
+ * compatible with UNION);
+ * - for ENUMs, the size is ignored;
+ * - for INT, size and signedness are ignored;
+ * - for ARRAY, dimensionality is ignored, element types are checked for
+ * compatibility recursively;
+ * - CONST/VOLATILE/RESTRICT modifiers are ignored;
+ * - TYPEDEFs/PTRs are compatible if types they pointing to are compatible;
+ * - FUNC_PROTOs are compatible if they have compatible signature: same
+ * number of input args and compatible return and argument types.
+ * These rules are not set in stone and probably will be adjusted as we get
+ * more experience with using BPF CO-RE relocations.
+ */
+static int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
+ const struct btf *targ_btf, __u32 targ_id)
+{
+ const struct btf_type *local_type, *targ_type;
+ int depth = 32; /* max recursion depth */
+
+ /* caller made sure that names match (ignoring flavor suffix) */
+ local_type = btf__type_by_id(local_btf, local_id);
+ targ_type = btf__type_by_id(targ_btf, targ_id);
+ if (btf_kind(local_type) != btf_kind(targ_type))
+ return 0;
+
+recur:
+ depth--;
+ if (depth < 0)
+ return -EINVAL;
+
+ local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id);
+ targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
+ if (!local_type || !targ_type)
+ return -EINVAL;
+
+ if (btf_kind(local_type) != btf_kind(targ_type))
+ return 0;
+
+ switch (btf_kind(local_type)) {
+ case BTF_KIND_UNKN:
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION:
+ case BTF_KIND_ENUM:
+ case BTF_KIND_FWD:
+ return 1;
+ case BTF_KIND_INT:
+ /* just reject deprecated bitfield-like integers; all other
+ * integers are by default compatible between each other
+ */
+ return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0;
+ case BTF_KIND_PTR:
+ local_id = local_type->type;
+ targ_id = targ_type->type;
+ goto recur;
+ case BTF_KIND_ARRAY:
+ local_id = btf_array(local_type)->type;
+ targ_id = btf_array(targ_type)->type;
+ goto recur;
+ case BTF_KIND_FUNC_PROTO: {
+ struct btf_param *local_p = btf_params(local_type);
+ struct btf_param *targ_p = btf_params(targ_type);
+ __u16 local_vlen = btf_vlen(local_type);
+ __u16 targ_vlen = btf_vlen(targ_type);
+ int i, err;
+
+ if (local_vlen != targ_vlen)
+ return 0;
+
+ for (i = 0; i < local_vlen; i++, local_p++, targ_p++) {
+ skip_mods_and_typedefs(local_btf, local_p->type, &local_id);
+ skip_mods_and_typedefs(targ_btf, targ_p->type, &targ_id);
+ err = bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id);
+ if (err <= 0)
+ return err;
+ }
+
+ /* tail recurse for return type check */
+ skip_mods_and_typedefs(local_btf, local_type->type, &local_id);
+ skip_mods_and_typedefs(targ_btf, targ_type->type, &targ_id);
+ goto recur;
+ }
+ default:
+ pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n",
+ btf_kind_str(local_type), local_id, targ_id);
+ return 0;
+ }
+}
+
+/*
+ * Try to match local spec to a target type and, if successful, produce full
+ * target spec (high-level, low-level + bit offset).
+ */
+static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
+ const struct btf *targ_btf, __u32 targ_id,
+ struct bpf_core_spec *targ_spec)
+{
+ const struct btf_type *targ_type;
+ const struct bpf_core_accessor *local_acc;
+ struct bpf_core_accessor *targ_acc;
+ int i, sz, matched;
+
+ memset(targ_spec, 0, sizeof(*targ_spec));
+ targ_spec->btf = targ_btf;
+ targ_spec->root_type_id = targ_id;
+ targ_spec->relo_kind = local_spec->relo_kind;
+
+ if (core_relo_is_type_based(local_spec->relo_kind)) {
+ return bpf_core_types_are_compat(local_spec->btf,
+ local_spec->root_type_id,
+ targ_btf, targ_id);
+ }
+
+ local_acc = &local_spec->spec[0];
+ targ_acc = &targ_spec->spec[0];
+
+ if (core_relo_is_enumval_based(local_spec->relo_kind)) {
+ size_t local_essent_len, targ_essent_len;
+ const struct btf_enum *e;
+ const char *targ_name;
+
+ /* has to resolve to an enum */
+ targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id, &targ_id);
+ if (!btf_is_enum(targ_type))
+ return 0;
+
+ local_essent_len = bpf_core_essential_name_len(local_acc->name);
+
+ for (i = 0, e = btf_enum(targ_type); i < btf_vlen(targ_type); i++, e++) {
+ targ_name = btf__name_by_offset(targ_spec->btf, e->name_off);
+ targ_essent_len = bpf_core_essential_name_len(targ_name);
+ if (targ_essent_len != local_essent_len)
+ continue;
+ if (strncmp(local_acc->name, targ_name, local_essent_len) == 0) {
+ targ_acc->type_id = targ_id;
+ targ_acc->idx = i;
+ targ_acc->name = targ_name;
+ targ_spec->len++;
+ targ_spec->raw_spec[targ_spec->raw_len] = targ_acc->idx;
+ targ_spec->raw_len++;
+ return 1;
}
- insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
- insns[insn_idx].imm = obj->maps[map_idx].fd;
+ }
+ return 0;
+ }
+
+ if (!core_relo_is_field_based(local_spec->relo_kind))
+ return -EINVAL;
+
+ for (i = 0; i < local_spec->len; i++, local_acc++, targ_acc++) {
+ targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id,
+ &targ_id);
+ if (!targ_type)
+ return -EINVAL;
+
+ if (local_acc->name) {
+ matched = bpf_core_match_member(local_spec->btf,
+ local_acc,
+ targ_btf, targ_id,
+ targ_spec, &targ_id);
+ if (matched <= 0)
+ return matched;
} else {
- err = bpf_program__reloc_text(prog, obj,
- &prog->reloc_desc[i]);
+ /* for i=0, targ_id is already treated as array element
+ * type (because it's the original struct), for others
+ * we should find array element type first
+ */
+ if (i > 0) {
+ const struct btf_array *a;
+ bool flex;
+
+ if (!btf_is_array(targ_type))
+ return 0;
+
+ a = btf_array(targ_type);
+ flex = is_flex_arr(targ_btf, targ_acc - 1, a);
+ if (!flex && local_acc->idx >= a->nelems)
+ return 0;
+ if (!skip_mods_and_typedefs(targ_btf, a->type,
+ &targ_id))
+ return -EINVAL;
+ }
+
+ /* too deep struct/union/array nesting */
+ if (targ_spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
+ return -E2BIG;
+
+ targ_acc->type_id = targ_id;
+ targ_acc->idx = local_acc->idx;
+ targ_acc->name = NULL;
+ targ_spec->len++;
+ targ_spec->raw_spec[targ_spec->raw_len] = targ_acc->idx;
+ targ_spec->raw_len++;
+
+ sz = btf__resolve_size(targ_btf, targ_id);
+ if (sz < 0)
+ return sz;
+ targ_spec->bit_offset += local_acc->idx * sz * 8;
+ }
+ }
+
+ return 1;
+}
+
+static int bpf_core_calc_field_relo(const struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ const struct bpf_core_spec *spec,
+ __u32 *val, __u32 *field_sz, __u32 *type_id,
+ bool *validate)
+{
+ const struct bpf_core_accessor *acc;
+ const struct btf_type *t;
+ __u32 byte_off, byte_sz, bit_off, bit_sz, field_type_id;
+ const struct btf_member *m;
+ const struct btf_type *mt;
+ bool bitfield;
+ __s64 sz;
+
+ *field_sz = 0;
+
+ if (relo->kind == BPF_FIELD_EXISTS) {
+ *val = spec ? 1 : 0;
+ return 0;
+ }
+
+ if (!spec)
+ return -EUCLEAN; /* request instruction poisoning */
+
+ acc = &spec->spec[spec->len - 1];
+ t = btf__type_by_id(spec->btf, acc->type_id);
+
+ /* a[n] accessor needs special handling */
+ if (!acc->name) {
+ if (relo->kind == BPF_FIELD_BYTE_OFFSET) {
+ *val = spec->bit_offset / 8;
+ /* remember field size for load/store mem size */
+ sz = btf__resolve_size(spec->btf, acc->type_id);
+ if (sz < 0)
+ return -EINVAL;
+ *field_sz = sz;
+ *type_id = acc->type_id;
+ } else if (relo->kind == BPF_FIELD_BYTE_SIZE) {
+ sz = btf__resolve_size(spec->btf, acc->type_id);
+ if (sz < 0)
+ return -EINVAL;
+ *val = sz;
+ } else {
+ pr_warn("prog '%s': relo %d at insn #%d can't be applied to array access\n",
+ prog->name, relo->kind, relo->insn_off / 8);
+ return -EINVAL;
+ }
+ if (validate)
+ *validate = true;
+ return 0;
+ }
+
+ m = btf_members(t) + acc->idx;
+ mt = skip_mods_and_typedefs(spec->btf, m->type, &field_type_id);
+ bit_off = spec->bit_offset;
+ bit_sz = btf_member_bitfield_size(t, acc->idx);
+
+ bitfield = bit_sz > 0;
+ if (bitfield) {
+ byte_sz = mt->size;
+ byte_off = bit_off / 8 / byte_sz * byte_sz;
+ /* figure out smallest int size necessary for bitfield load */
+ while (bit_off + bit_sz - byte_off * 8 > byte_sz * 8) {
+ if (byte_sz >= 8) {
+ /* bitfield can't be read with 64-bit read */
+ pr_warn("prog '%s': relo %d at insn #%d can't be satisfied for bitfield\n",
+ prog->name, relo->kind, relo->insn_off / 8);
+ return -E2BIG;
+ }
+ byte_sz *= 2;
+ byte_off = bit_off / 8 / byte_sz * byte_sz;
+ }
+ } else {
+ sz = btf__resolve_size(spec->btf, field_type_id);
+ if (sz < 0)
+ return -EINVAL;
+ byte_sz = sz;
+ byte_off = spec->bit_offset / 8;
+ bit_sz = byte_sz * 8;
+ }
+
+ /* for bitfields, all the relocatable aspects are ambiguous and we
+ * might disagree with compiler, so turn off validation of expected
+ * value, except for signedness
+ */
+ if (validate)
+ *validate = !bitfield;
+
+ switch (relo->kind) {
+ case BPF_FIELD_BYTE_OFFSET:
+ *val = byte_off;
+ if (!bitfield) {
+ *field_sz = byte_sz;
+ *type_id = field_type_id;
+ }
+ break;
+ case BPF_FIELD_BYTE_SIZE:
+ *val = byte_sz;
+ break;
+ case BPF_FIELD_SIGNED:
+ /* enums will be assumed unsigned */
+ *val = btf_is_enum(mt) ||
+ (btf_int_encoding(mt) & BTF_INT_SIGNED);
+ if (validate)
+ *validate = true; /* signedness is never ambiguous */
+ break;
+ case BPF_FIELD_LSHIFT_U64:
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ *val = 64 - (bit_off + bit_sz - byte_off * 8);
+#else
+ *val = (8 - byte_sz) * 8 + (bit_off - byte_off * 8);
+#endif
+ break;
+ case BPF_FIELD_RSHIFT_U64:
+ *val = 64 - bit_sz;
+ if (validate)
+ *validate = true; /* right shift is never ambiguous */
+ break;
+ case BPF_FIELD_EXISTS:
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int bpf_core_calc_type_relo(const struct bpf_core_relo *relo,
+ const struct bpf_core_spec *spec,
+ __u32 *val)
+{
+ __s64 sz;
+
+ /* type-based relos return zero when target type is not found */
+ if (!spec) {
+ *val = 0;
+ return 0;
+ }
+
+ switch (relo->kind) {
+ case BPF_TYPE_ID_TARGET:
+ *val = spec->root_type_id;
+ break;
+ case BPF_TYPE_EXISTS:
+ *val = 1;
+ break;
+ case BPF_TYPE_SIZE:
+ sz = btf__resolve_size(spec->btf, spec->root_type_id);
+ if (sz < 0)
+ return -EINVAL;
+ *val = sz;
+ break;
+ case BPF_TYPE_ID_LOCAL:
+ /* BPF_TYPE_ID_LOCAL is handled specially and shouldn't get here */
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int bpf_core_calc_enumval_relo(const struct bpf_core_relo *relo,
+ const struct bpf_core_spec *spec,
+ __u32 *val)
+{
+ const struct btf_type *t;
+ const struct btf_enum *e;
+
+ switch (relo->kind) {
+ case BPF_ENUMVAL_EXISTS:
+ *val = spec ? 1 : 0;
+ break;
+ case BPF_ENUMVAL_VALUE:
+ if (!spec)
+ return -EUCLEAN; /* request instruction poisoning */
+ t = btf__type_by_id(spec->btf, spec->spec[0].type_id);
+ e = btf_enum(t) + spec->spec[0].idx;
+ *val = e->val;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+struct bpf_core_relo_res
+{
+ /* expected value in the instruction, unless validate == false */
+ __u32 orig_val;
+ /* new value that needs to be patched up to */
+ __u32 new_val;
+ /* relocation unsuccessful, poison instruction, but don't fail load */
+ bool poison;
+ /* some relocations can't be validated against orig_val */
+ bool validate;
+ /* for field byte offset relocations or the forms:
+ * *(T *)(rX + <off>) = rY
+ * rX = *(T *)(rY + <off>),
+ * we remember original and resolved field size to adjust direct
+ * memory loads of pointers and integers; this is necessary for 32-bit
+ * host kernel architectures, but also allows to automatically
+ * relocate fields that were resized from, e.g., u32 to u64, etc.
+ */
+ bool fail_memsz_adjust;
+ __u32 orig_sz;
+ __u32 orig_type_id;
+ __u32 new_sz;
+ __u32 new_type_id;
+};
+
+/* Calculate original and target relocation values, given local and target
+ * specs and relocation kind. These values are calculated for each candidate.
+ * If there are multiple candidates, resulting values should all be consistent
+ * with each other. Otherwise, libbpf will refuse to proceed due to ambiguity.
+ * If instruction has to be poisoned, *poison will be set to true.
+ */
+static int bpf_core_calc_relo(const struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct bpf_core_spec *local_spec,
+ const struct bpf_core_spec *targ_spec,
+ struct bpf_core_relo_res *res)
+{
+ int err = -EOPNOTSUPP;
+
+ res->orig_val = 0;
+ res->new_val = 0;
+ res->poison = false;
+ res->validate = true;
+ res->fail_memsz_adjust = false;
+ res->orig_sz = res->new_sz = 0;
+ res->orig_type_id = res->new_type_id = 0;
+
+ if (core_relo_is_field_based(relo->kind)) {
+ err = bpf_core_calc_field_relo(prog, relo, local_spec,
+ &res->orig_val, &res->orig_sz,
+ &res->orig_type_id, &res->validate);
+ err = err ?: bpf_core_calc_field_relo(prog, relo, targ_spec,
+ &res->new_val, &res->new_sz,
+ &res->new_type_id, NULL);
+ if (err)
+ goto done;
+ /* Validate if it's safe to adjust load/store memory size.
+ * Adjustments are performed only if original and new memory
+ * sizes differ.
+ */
+ res->fail_memsz_adjust = false;
+ if (res->orig_sz != res->new_sz) {
+ const struct btf_type *orig_t, *new_t;
+
+ orig_t = btf__type_by_id(local_spec->btf, res->orig_type_id);
+ new_t = btf__type_by_id(targ_spec->btf, res->new_type_id);
+
+ /* There are two use cases in which it's safe to
+ * adjust load/store's mem size:
+ * - reading a 32-bit kernel pointer, while on BPF
+ * size pointers are always 64-bit; in this case
+ * it's safe to "downsize" instruction size due to
+ * pointer being treated as unsigned integer with
+ * zero-extended upper 32-bits;
+ * - reading unsigned integers, again due to
+ * zero-extension is preserving the value correctly.
+ *
+ * In all other cases it's incorrect to attempt to
+ * load/store field because read value will be
+ * incorrect, so we poison relocated instruction.
+ */
+ if (btf_is_ptr(orig_t) && btf_is_ptr(new_t))
+ goto done;
+ if (btf_is_int(orig_t) && btf_is_int(new_t) &&
+ btf_int_encoding(orig_t) != BTF_INT_SIGNED &&
+ btf_int_encoding(new_t) != BTF_INT_SIGNED)
+ goto done;
+
+ /* mark as invalid mem size adjustment, but this will
+ * only be checked for LDX/STX/ST insns
+ */
+ res->fail_memsz_adjust = true;
+ }
+ } else if (core_relo_is_type_based(relo->kind)) {
+ err = bpf_core_calc_type_relo(relo, local_spec, &res->orig_val);
+ err = err ?: bpf_core_calc_type_relo(relo, targ_spec, &res->new_val);
+ } else if (core_relo_is_enumval_based(relo->kind)) {
+ err = bpf_core_calc_enumval_relo(relo, local_spec, &res->orig_val);
+ err = err ?: bpf_core_calc_enumval_relo(relo, targ_spec, &res->new_val);
+ }
+
+done:
+ if (err == -EUCLEAN) {
+ /* EUCLEAN is used to signal instruction poisoning request */
+ res->poison = true;
+ err = 0;
+ } else if (err == -EOPNOTSUPP) {
+ /* EOPNOTSUPP means unknown/unsupported relocation */
+ pr_warn("prog '%s': relo #%d: unrecognized CO-RE relocation %s (%d) at insn #%d\n",
+ prog->name, relo_idx, core_relo_kind_str(relo->kind),
+ relo->kind, relo->insn_off / 8);
+ }
+
+ return err;
+}
+
+/*
+ * Turn instruction for which CO_RE relocation failed into invalid one with
+ * distinct signature.
+ */
+static void bpf_core_poison_insn(struct bpf_program *prog, int relo_idx,
+ int insn_idx, struct bpf_insn *insn)
+{
+ pr_debug("prog '%s': relo #%d: substituting insn #%d w/ invalid insn\n",
+ prog->name, relo_idx, insn_idx);
+ insn->code = BPF_JMP | BPF_CALL;
+ insn->dst_reg = 0;
+ insn->src_reg = 0;
+ insn->off = 0;
+ /* if this instruction is reachable (not a dead code),
+ * verifier will complain with the following message:
+ * invalid func unknown#195896080
+ */
+ insn->imm = 195896080; /* => 0xbad2310 => "bad relo" */
+}
+
+static bool is_ldimm64(struct bpf_insn *insn)
+{
+ return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
+}
+
+static int insn_bpf_size_to_bytes(struct bpf_insn *insn)
+{
+ switch (BPF_SIZE(insn->code)) {
+ case BPF_DW: return 8;
+ case BPF_W: return 4;
+ case BPF_H: return 2;
+ case BPF_B: return 1;
+ default: return -1;
+ }
+}
+
+static int insn_bytes_to_bpf_size(__u32 sz)
+{
+ switch (sz) {
+ case 8: return BPF_DW;
+ case 4: return BPF_W;
+ case 2: return BPF_H;
+ case 1: return BPF_B;
+ default: return -1;
+ }
+}
+
+/*
+ * Patch relocatable BPF instruction.
+ *
+ * Patched value is determined by relocation kind and target specification.
+ * For existence relocations target spec will be NULL if field/type is not found.
+ * Expected insn->imm value is determined using relocation kind and local
+ * spec, and is checked before patching instruction. If actual insn->imm value
+ * is wrong, bail out with error.
+ *
+ * Currently supported classes of BPF instruction are:
+ * 1. rX = <imm> (assignment with immediate operand);
+ * 2. rX += <imm> (arithmetic operations with immediate operand);
+ * 3. rX = <imm64> (load with 64-bit immediate value);
+ * 4. rX = *(T *)(rY + <off>), where T is one of {u8, u16, u32, u64};
+ * 5. *(T *)(rX + <off>) = rY, where T is one of {u8, u16, u32, u64};
+ * 6. *(T *)(rX + <off>) = <imm>, where T is one of {u8, u16, u32, u64}.
+ */
+static int bpf_core_patch_insn(struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct bpf_core_relo_res *res)
+{
+ __u32 orig_val, new_val;
+ struct bpf_insn *insn;
+ int insn_idx;
+ __u8 class;
+
+ if (relo->insn_off % BPF_INSN_SZ)
+ return -EINVAL;
+ insn_idx = relo->insn_off / BPF_INSN_SZ;
+ /* adjust insn_idx from section frame of reference to the local
+ * program's frame of reference; (sub-)program code is not yet
+ * relocated, so it's enough to just subtract in-section offset
+ */
+ insn_idx = insn_idx - prog->sec_insn_off;
+ insn = &prog->insns[insn_idx];
+ class = BPF_CLASS(insn->code);
+
+ if (res->poison) {
+poison:
+ /* poison second part of ldimm64 to avoid confusing error from
+ * verifier about "unknown opcode 00"
+ */
+ if (is_ldimm64(insn))
+ bpf_core_poison_insn(prog, relo_idx, insn_idx + 1, insn + 1);
+ bpf_core_poison_insn(prog, relo_idx, insn_idx, insn);
+ return 0;
+ }
+
+ orig_val = res->orig_val;
+ new_val = res->new_val;
+
+ switch (class) {
+ case BPF_ALU:
+ case BPF_ALU64:
+ if (BPF_SRC(insn->code) != BPF_K)
+ return -EINVAL;
+ if (res->validate && insn->imm != orig_val) {
+ pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %u -> %u\n",
+ prog->name, relo_idx,
+ insn_idx, insn->imm, orig_val, new_val);
+ return -EINVAL;
+ }
+ orig_val = insn->imm;
+ insn->imm = new_val;
+ pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %u -> %u\n",
+ prog->name, relo_idx, insn_idx,
+ orig_val, new_val);
+ break;
+ case BPF_LDX:
+ case BPF_ST:
+ case BPF_STX:
+ if (res->validate && insn->off != orig_val) {
+ pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDX/ST/STX) value: got %u, exp %u -> %u\n",
+ prog->name, relo_idx, insn_idx, insn->off, orig_val, new_val);
+ return -EINVAL;
+ }
+ if (new_val > SHRT_MAX) {
+ pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %u\n",
+ prog->name, relo_idx, insn_idx, new_val);
+ return -ERANGE;
+ }
+ if (res->fail_memsz_adjust) {
+ pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) accesses field incorrectly. "
+ "Make sure you are accessing pointers, unsigned integers, or fields of matching type and size.\n",
+ prog->name, relo_idx, insn_idx);
+ goto poison;
+ }
+
+ orig_val = insn->off;
+ insn->off = new_val;
+ pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %u -> %u\n",
+ prog->name, relo_idx, insn_idx, orig_val, new_val);
+
+ if (res->new_sz != res->orig_sz) {
+ int insn_bytes_sz, insn_bpf_sz;
+
+ insn_bytes_sz = insn_bpf_size_to_bytes(insn);
+ if (insn_bytes_sz != res->orig_sz) {
+ pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) unexpected mem size: got %d, exp %u\n",
+ prog->name, relo_idx, insn_idx, insn_bytes_sz, res->orig_sz);
+ return -EINVAL;
+ }
+
+ insn_bpf_sz = insn_bytes_to_bpf_size(res->new_sz);
+ if (insn_bpf_sz < 0) {
+ pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) invalid new mem size: %u\n",
+ prog->name, relo_idx, insn_idx, res->new_sz);
+ return -EINVAL;
+ }
+
+ insn->code = BPF_MODE(insn->code) | insn_bpf_sz | BPF_CLASS(insn->code);
+ pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) mem_sz %u -> %u\n",
+ prog->name, relo_idx, insn_idx, res->orig_sz, res->new_sz);
+ }
+ break;
+ case BPF_LD: {
+ __u64 imm;
+
+ if (!is_ldimm64(insn) ||
+ insn[0].src_reg != 0 || insn[0].off != 0 ||
+ insn_idx + 1 >= prog->insns_cnt ||
+ insn[1].code != 0 || insn[1].dst_reg != 0 ||
+ insn[1].src_reg != 0 || insn[1].off != 0) {
+ pr_warn("prog '%s': relo #%d: insn #%d (LDIMM64) has unexpected form\n",
+ prog->name, relo_idx, insn_idx);
+ return -EINVAL;
+ }
+
+ imm = insn[0].imm + ((__u64)insn[1].imm << 32);
+ if (res->validate && imm != orig_val) {
+ pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %u -> %u\n",
+ prog->name, relo_idx,
+ insn_idx, (unsigned long long)imm,
+ orig_val, new_val);
+ return -EINVAL;
+ }
+
+ insn[0].imm = new_val;
+ insn[1].imm = 0; /* currently only 32-bit values are supported */
+ pr_debug("prog '%s': relo #%d: patched insn #%d (LDIMM64) imm64 %llu -> %u\n",
+ prog->name, relo_idx, insn_idx,
+ (unsigned long long)imm, new_val);
+ break;
+ }
+ default:
+ pr_warn("prog '%s': relo #%d: trying to relocate unrecognized insn #%d, code:0x%x, src:0x%x, dst:0x%x, off:0x%x, imm:0x%x\n",
+ prog->name, relo_idx, insn_idx, insn->code,
+ insn->src_reg, insn->dst_reg, insn->off, insn->imm);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/* Output spec definition in the format:
+ * [<type-id>] (<type-name>) + <raw-spec> => <offset>@<spec>,
+ * where <spec> is a C-syntax view of recorded field access, e.g.: x.a[3].b
+ */
+static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
+{
+ const struct btf_type *t;
+ const struct btf_enum *e;
+ const char *s;
+ __u32 type_id;
+ int i;
+
+ type_id = spec->root_type_id;
+ t = btf__type_by_id(spec->btf, type_id);
+ s = btf__name_by_offset(spec->btf, t->name_off);
+
+ libbpf_print(level, "[%u] %s %s", type_id, btf_kind_str(t), str_is_empty(s) ? "<anon>" : s);
+
+ if (core_relo_is_type_based(spec->relo_kind))
+ return;
+
+ if (core_relo_is_enumval_based(spec->relo_kind)) {
+ t = skip_mods_and_typedefs(spec->btf, type_id, NULL);
+ e = btf_enum(t) + spec->raw_spec[0];
+ s = btf__name_by_offset(spec->btf, e->name_off);
+
+ libbpf_print(level, "::%s = %u", s, e->val);
+ return;
+ }
+
+ if (core_relo_is_field_based(spec->relo_kind)) {
+ for (i = 0; i < spec->len; i++) {
+ if (spec->spec[i].name)
+ libbpf_print(level, ".%s", spec->spec[i].name);
+ else if (i > 0 || spec->spec[i].idx > 0)
+ libbpf_print(level, "[%u]", spec->spec[i].idx);
+ }
+
+ libbpf_print(level, " (");
+ for (i = 0; i < spec->raw_len; i++)
+ libbpf_print(level, "%s%d", i == 0 ? "" : ":", spec->raw_spec[i]);
+
+ if (spec->bit_offset % 8)
+ libbpf_print(level, " @ offset %u.%u)",
+ spec->bit_offset / 8, spec->bit_offset % 8);
+ else
+ libbpf_print(level, " @ offset %u)", spec->bit_offset / 8);
+ return;
+ }
+}
+
+static size_t bpf_core_hash_fn(const void *key, void *ctx)
+{
+ return (size_t)key;
+}
+
+static bool bpf_core_equal_fn(const void *k1, const void *k2, void *ctx)
+{
+ return k1 == k2;
+}
+
+static void *u32_as_hash_key(__u32 x)
+{
+ return (void *)(uintptr_t)x;
+}
+
+/*
+ * CO-RE relocate single instruction.
+ *
+ * The outline and important points of the algorithm:
+ * 1. For given local type, find corresponding candidate target types.
+ * Candidate type is a type with the same "essential" name, ignoring
+ * everything after last triple underscore (___). E.g., `sample`,
+ * `sample___flavor_one`, `sample___flavor_another_one`, are all candidates
+ * for each other. Names with triple underscore are referred to as
+ * "flavors" and are useful, among other things, to allow to
+ * specify/support incompatible variations of the same kernel struct, which
+ * might differ between different kernel versions and/or build
+ * configurations.
+ *
+ * N.B. Struct "flavors" could be generated by bpftool's BTF-to-C
+ * converter, when deduplicated BTF of a kernel still contains more than
+ * one different types with the same name. In that case, ___2, ___3, etc
+ * are appended starting from second name conflict. But start flavors are
+ * also useful to be defined "locally", in BPF program, to extract same
+ * data from incompatible changes between different kernel
+ * versions/configurations. For instance, to handle field renames between
+ * kernel versions, one can use two flavors of the struct name with the
+ * same common name and use conditional relocations to extract that field,
+ * depending on target kernel version.
+ * 2. For each candidate type, try to match local specification to this
+ * candidate target type. Matching involves finding corresponding
+ * high-level spec accessors, meaning that all named fields should match,
+ * as well as all array accesses should be within the actual bounds. Also,
+ * types should be compatible (see bpf_core_fields_are_compat for details).
+ * 3. It is supported and expected that there might be multiple flavors
+ * matching the spec. As long as all the specs resolve to the same set of
+ * offsets across all candidates, there is no error. If there is any
+ * ambiguity, CO-RE relocation will fail. This is necessary to accomodate
+ * imprefection of BTF deduplication, which can cause slight duplication of
+ * the same BTF type, if some directly or indirectly referenced (by
+ * pointer) type gets resolved to different actual types in different
+ * object files. If such situation occurs, deduplicated BTF will end up
+ * with two (or more) structurally identical types, which differ only in
+ * types they refer to through pointer. This should be OK in most cases and
+ * is not an error.
+ * 4. Candidate types search is performed by linearly scanning through all
+ * types in target BTF. It is anticipated that this is overall more
+ * efficient memory-wise and not significantly worse (if not better)
+ * CPU-wise compared to prebuilding a map from all local type names to
+ * a list of candidate type names. It's also sped up by caching resolved
+ * list of matching candidates per each local "root" type ID, that has at
+ * least one bpf_core_relo associated with it. This list is shared
+ * between multiple relocations for the same type ID and is updated as some
+ * of the candidates are pruned due to structural incompatibility.
+ */
+static int bpf_core_apply_relo(struct bpf_program *prog,
+ const struct bpf_core_relo *relo,
+ int relo_idx,
+ const struct btf *local_btf,
+ const struct btf *targ_btf,
+ struct hashmap *cand_cache)
+{
+ struct bpf_core_spec local_spec, cand_spec, targ_spec = {};
+ const void *type_key = u32_as_hash_key(relo->type_id);
+ struct bpf_core_relo_res cand_res, targ_res;
+ const struct btf_type *local_type;
+ const char *local_name;
+ struct ids_vec *cand_ids;
+ __u32 local_id, cand_id;
+ const char *spec_str;
+ int i, j, err;
+
+ local_id = relo->type_id;
+ local_type = btf__type_by_id(local_btf, local_id);
+ if (!local_type)
+ return -EINVAL;
+
+ local_name = btf__name_by_offset(local_btf, local_type->name_off);
+ if (!local_name)
+ return -EINVAL;
+
+ spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
+ if (str_is_empty(spec_str))
+ return -EINVAL;
+
+ err = bpf_core_parse_spec(local_btf, local_id, spec_str, relo->kind, &local_spec);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: parsing [%d] %s %s + %s failed: %d\n",
+ prog->name, relo_idx, local_id, btf_kind_str(local_type),
+ str_is_empty(local_name) ? "<anon>" : local_name,
+ spec_str, err);
+ return -EINVAL;
+ }
+
+ pr_debug("prog '%s': relo #%d: kind <%s> (%d), spec is ", prog->name,
+ relo_idx, core_relo_kind_str(relo->kind), relo->kind);
+ bpf_core_dump_spec(LIBBPF_DEBUG, &local_spec);
+ libbpf_print(LIBBPF_DEBUG, "\n");
+
+ /* TYPE_ID_LOCAL relo is special and doesn't need candidate search */
+ if (relo->kind == BPF_TYPE_ID_LOCAL) {
+ targ_res.validate = true;
+ targ_res.poison = false;
+ targ_res.orig_val = local_spec.root_type_id;
+ targ_res.new_val = local_spec.root_type_id;
+ goto patch_insn;
+ }
+
+ /* libbpf doesn't support candidate search for anonymous types */
+ if (str_is_empty(spec_str)) {
+ pr_warn("prog '%s': relo #%d: <%s> (%d) relocation doesn't support anonymous types\n",
+ prog->name, relo_idx, core_relo_kind_str(relo->kind), relo->kind);
+ return -EOPNOTSUPP;
+ }
+
+ if (!hashmap__find(cand_cache, type_key, (void **)&cand_ids)) {
+ cand_ids = bpf_core_find_cands(local_btf, local_id, targ_btf);
+ if (IS_ERR(cand_ids)) {
+ pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s %s: %ld",
+ prog->name, relo_idx, local_id, btf_kind_str(local_type),
+ local_name, PTR_ERR(cand_ids));
+ return PTR_ERR(cand_ids);
+ }
+ err = hashmap__set(cand_cache, type_key, cand_ids, NULL, NULL);
+ if (err) {
+ bpf_core_free_cands(cand_ids);
+ return err;
+ }
+ }
+
+ for (i = 0, j = 0; i < cand_ids->len; i++) {
+ cand_id = cand_ids->data[i];
+ err = bpf_core_spec_match(&local_spec, targ_btf, cand_id, &cand_spec);
+ if (err < 0) {
+ pr_warn("prog '%s': relo #%d: error matching candidate #%d ",
+ prog->name, relo_idx, i);
+ bpf_core_dump_spec(LIBBPF_WARN, &cand_spec);
+ libbpf_print(LIBBPF_WARN, ": %d\n", err);
+ return err;
+ }
+
+ pr_debug("prog '%s': relo #%d: %s candidate #%d ", prog->name,
+ relo_idx, err == 0 ? "non-matching" : "matching", i);
+ bpf_core_dump_spec(LIBBPF_DEBUG, &cand_spec);
+ libbpf_print(LIBBPF_DEBUG, "\n");
+
+ if (err == 0)
+ continue;
+
+ err = bpf_core_calc_relo(prog, relo, relo_idx, &local_spec, &cand_spec, &cand_res);
+ if (err)
+ return err;
+
+ if (j == 0) {
+ targ_res = cand_res;
+ targ_spec = cand_spec;
+ } else if (cand_spec.bit_offset != targ_spec.bit_offset) {
+ /* if there are many field relo candidates, they
+ * should all resolve to the same bit offset
+ */
+ pr_warn("prog '%s': relo #%d: field offset ambiguity: %u != %u\n",
+ prog->name, relo_idx, cand_spec.bit_offset,
+ targ_spec.bit_offset);
+ return -EINVAL;
+ } else if (cand_res.poison != targ_res.poison || cand_res.new_val != targ_res.new_val) {
+ /* all candidates should result in the same relocation
+ * decision and value, otherwise it's dangerous to
+ * proceed due to ambiguity
+ */
+ pr_warn("prog '%s': relo #%d: relocation decision ambiguity: %s %u != %s %u\n",
+ prog->name, relo_idx,
+ cand_res.poison ? "failure" : "success", cand_res.new_val,
+ targ_res.poison ? "failure" : "success", targ_res.new_val);
+ return -EINVAL;
+ }
+
+ cand_ids->data[j++] = cand_spec.root_type_id;
+ }
+
+ /*
+ * For BPF_FIELD_EXISTS relo or when used BPF program has field
+ * existence checks or kernel version/config checks, it's expected
+ * that we might not find any candidates. In this case, if field
+ * wasn't found in any candidate, the list of candidates shouldn't
+ * change at all, we'll just handle relocating appropriately,
+ * depending on relo's kind.
+ */
+ if (j > 0)
+ cand_ids->len = j;
+
+ /*
+ * If no candidates were found, it might be both a programmer error,
+ * as well as expected case, depending whether instruction w/
+ * relocation is guarded in some way that makes it unreachable (dead
+ * code) if relocation can't be resolved. This is handled in
+ * bpf_core_patch_insn() uniformly by replacing that instruction with
+ * BPF helper call insn (using invalid helper ID). If that instruction
+ * is indeed unreachable, then it will be ignored and eliminated by
+ * verifier. If it was an error, then verifier will complain and point
+ * to a specific instruction number in its log.
+ */
+ if (j == 0) {
+ pr_debug("prog '%s': relo #%d: no matching targets found\n",
+ prog->name, relo_idx);
+
+ /* calculate single target relo result explicitly */
+ err = bpf_core_calc_relo(prog, relo, relo_idx, &local_spec, NULL, &targ_res);
+ if (err)
+ return err;
+ }
+
+patch_insn:
+ /* bpf_core_patch_insn() should know how to handle missing targ_spec */
+ err = bpf_core_patch_insn(prog, relo, relo_idx, &targ_res);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: failed to patch insn at offset %d: %d\n",
+ prog->name, relo_idx, relo->insn_off, err);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
+{
+ const struct btf_ext_info_sec *sec;
+ const struct bpf_core_relo *rec;
+ const struct btf_ext_info *seg;
+ struct hashmap_entry *entry;
+ struct hashmap *cand_cache = NULL;
+ struct bpf_program *prog;
+ struct btf *targ_btf;
+ const char *sec_name;
+ int i, err = 0, insn_idx, sec_idx;
+
+ if (obj->btf_ext->core_relo_info.len == 0)
+ return 0;
+
+ if (targ_btf_path)
+ targ_btf = btf__parse(targ_btf_path, NULL);
+ else
+ targ_btf = obj->btf_vmlinux;
+ if (IS_ERR_OR_NULL(targ_btf)) {
+ pr_warn("failed to get target BTF: %ld\n", PTR_ERR(targ_btf));
+ return PTR_ERR(targ_btf);
+ }
+
+ cand_cache = hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn, NULL);
+ if (IS_ERR(cand_cache)) {
+ err = PTR_ERR(cand_cache);
+ goto out;
+ }
+
+ seg = &obj->btf_ext->core_relo_info;
+ for_each_btf_ext_sec(seg, sec) {
+ sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
+ if (str_is_empty(sec_name)) {
+ err = -EINVAL;
+ goto out;
+ }
+ /* bpf_object's ELF is gone by now so it's not easy to find
+ * section index by section name, but we can find *any*
+ * bpf_program within desired section name and use it's
+ * prog->sec_idx to do a proper search by section index and
+ * instruction offset
+ */
+ prog = NULL;
+ for (i = 0; i < obj->nr_programs; i++) {
+ if (strcmp(obj->programs[i].sec_name, sec_name) == 0) {
+ prog = &obj->programs[i];
+ break;
+ }
+ }
+ if (!prog) {
+ pr_warn("sec '%s': failed to find a BPF program\n", sec_name);
+ return -ENOENT;
+ }
+ sec_idx = prog->sec_idx;
+
+ pr_debug("sec '%s': found %d CO-RE relocations\n",
+ sec_name, sec->num_info);
+
+ for_each_btf_ext_rec(seg, sec, i, rec) {
+ insn_idx = rec->insn_off / BPF_INSN_SZ;
+ prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx);
+ if (!prog) {
+ /* When __weak subprog is "overridden" by another instance
+ * of the subprog from a different object file, linker still
+ * appends all the .BTF.ext info that used to belong to that
+ * eliminated subprogram.
+ * This is similar to what x86-64 linker does for relocations.
+ * So just ignore such relocations just like we ignore
+ * subprog instructions when discovering subprograms.
+ */
+ pr_debug("sec '%s': skipping CO-RE relocation #%d for insn #%d belonging to eliminated weak subprogram\n",
+ sec_name, i, insn_idx);
+ continue;
+ }
+ /* no need to apply CO-RE relocation if the program is
+ * not going to be loaded
+ */
+ if (!prog->load)
+ continue;
+
+ err = bpf_core_apply_relo(prog, rec, i, obj->btf,
+ targ_btf, cand_cache);
+ if (err) {
+ pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
+ prog->name, i, err);
+ goto out;
+ }
+ }
+ }
+
+out:
+ /* obj->btf_vmlinux is freed at the end of object load phase */
+ if (targ_btf != obj->btf_vmlinux)
+ btf__free(targ_btf);
+ if (!IS_ERR_OR_NULL(cand_cache)) {
+ hashmap__for_each_entry(cand_cache, entry, i) {
+ bpf_core_free_cands(entry->value);
+ }
+ hashmap__free(cand_cache);
+ }
+ return err;
+}
+
+/* Relocate data references within program code:
+ * - map references;
+ * - global variable references;
+ * - extern references.
+ */
+static int
+bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
+{
+ int i;
+
+ for (i = 0; i < prog->nr_reloc; i++) {
+ struct reloc_desc *relo = &prog->reloc_desc[i];
+ struct bpf_insn *insn = &prog->insns[relo->insn_idx];
+ struct extern_desc *ext;
+
+ switch (relo->type) {
+ case RELO_LD64:
+ insn[0].src_reg = BPF_PSEUDO_MAP_FD;
+ insn[0].imm = obj->maps[relo->map_idx].fd;
+ relo->processed = true;
+ break;
+ case RELO_DATA:
+ insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
+ insn[1].imm = insn[0].imm + relo->sym_off;
+ insn[0].imm = obj->maps[relo->map_idx].fd;
+ relo->processed = true;
+ break;
+ case RELO_EXTERN:
+ ext = &obj->externs[relo->sym_off];
+ if (ext->type == EXT_KCFG) {
+ insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
+ insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;
+ insn[1].imm = ext->kcfg.data_off;
+ } else /* EXT_KSYM */ {
+ if (ext->ksym.type_id) { /* typed ksyms */
+ insn[0].src_reg = BPF_PSEUDO_BTF_ID;
+ insn[0].imm = ext->ksym.vmlinux_btf_id;
+ } else { /* typeless ksyms */
+ insn[0].imm = (__u32)ext->ksym.addr;
+ insn[1].imm = ext->ksym.addr >> 32;
+ }
+ }
+ relo->processed = true;
+ break;
+ case RELO_CALL:
+ /* will be handled as a follow up pass */
+ break;
+ default:
+ pr_warn("prog '%s': relo #%d: bad relo type %d\n",
+ prog->name, i, relo->type);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int adjust_prog_btf_ext_info(const struct bpf_object *obj,
+ const struct bpf_program *prog,
+ const struct btf_ext_info *ext_info,
+ void **prog_info, __u32 *prog_rec_cnt,
+ __u32 *prog_rec_sz)
+{
+ void *copy_start = NULL, *copy_end = NULL;
+ void *rec, *rec_end, *new_prog_info;
+ const struct btf_ext_info_sec *sec;
+ size_t old_sz, new_sz;
+ const char *sec_name;
+ int i, off_adj;
+
+ for_each_btf_ext_sec(ext_info, sec) {
+ sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
+ if (!sec_name)
+ return -EINVAL;
+ if (strcmp(sec_name, prog->sec_name) != 0)
+ continue;
+
+ for_each_btf_ext_rec(ext_info, sec, i, rec) {
+ __u32 insn_off = *(__u32 *)rec / BPF_INSN_SZ;
+
+ if (insn_off < prog->sec_insn_off)
+ continue;
+ if (insn_off >= prog->sec_insn_off + prog->sec_insn_cnt)
+ break;
+
+ if (!copy_start)
+ copy_start = rec;
+ copy_end = rec + ext_info->rec_size;
+ }
+
+ if (!copy_start)
+ return -ENOENT;
+
+ /* append func/line info of a given (sub-)program to the main
+ * program func/line info
+ */
+ old_sz = (size_t)(*prog_rec_cnt) * ext_info->rec_size;
+ new_sz = old_sz + (copy_end - copy_start);
+ new_prog_info = realloc(*prog_info, new_sz);
+ if (!new_prog_info)
+ return -ENOMEM;
+ *prog_info = new_prog_info;
+ *prog_rec_cnt = new_sz / ext_info->rec_size;
+ memcpy(new_prog_info + old_sz, copy_start, copy_end - copy_start);
+
+ /* Kernel instruction offsets are in units of 8-byte
+ * instructions, while .BTF.ext instruction offsets generated
+ * by Clang are in units of bytes. So convert Clang offsets
+ * into kernel offsets and adjust offset according to program
+ * relocated position.
+ */
+ off_adj = prog->sub_insn_off - prog->sec_insn_off;
+ rec = new_prog_info + old_sz;
+ rec_end = new_prog_info + new_sz;
+ for (; rec < rec_end; rec += ext_info->rec_size) {
+ __u32 *insn_off = rec;
+
+ *insn_off = *insn_off / BPF_INSN_SZ + off_adj;
+ }
+ *prog_rec_sz = ext_info->rec_size;
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+static int
+reloc_prog_func_and_line_info(const struct bpf_object *obj,
+ struct bpf_program *main_prog,
+ const struct bpf_program *prog)
+{
+ int err;
+
+ /* no .BTF.ext relocation if .BTF.ext is missing or kernel doesn't
+ * supprot func/line info
+ */
+ if (!obj->btf_ext || !kernel_supports(FEAT_BTF_FUNC))
+ return 0;
+
+ /* only attempt func info relocation if main program's func_info
+ * relocation was successful
+ */
+ if (main_prog != prog && !main_prog->func_info)
+ goto line_info;
+
+ err = adjust_prog_btf_ext_info(obj, prog, &obj->btf_ext->func_info,
+ &main_prog->func_info,
+ &main_prog->func_info_cnt,
+ &main_prog->func_info_rec_size);
+ if (err) {
+ if (err != -ENOENT) {
+ pr_warn("prog '%s': error relocating .BTF.ext function info: %d\n",
+ prog->name, err);
+ return err;
+ }
+ if (main_prog->func_info) {
+ /*
+ * Some info has already been found but has problem
+ * in the last btf_ext reloc. Must have to error out.
+ */
+ pr_warn("prog '%s': missing .BTF.ext function info.\n", prog->name);
+ return err;
+ }
+ /* Have problem loading the very first info. Ignore the rest. */
+ pr_warn("prog '%s': missing .BTF.ext function info for the main program, skipping all of .BTF.ext func info.\n",
+ prog->name);
+ }
+
+line_info:
+ /* don't relocate line info if main program's relocation failed */
+ if (main_prog != prog && !main_prog->line_info)
+ return 0;
+
+ err = adjust_prog_btf_ext_info(obj, prog, &obj->btf_ext->line_info,
+ &main_prog->line_info,
+ &main_prog->line_info_cnt,
+ &main_prog->line_info_rec_size);
+ if (err) {
+ if (err != -ENOENT) {
+ pr_warn("prog '%s': error relocating .BTF.ext line info: %d\n",
+ prog->name, err);
+ return err;
+ }
+ if (main_prog->line_info) {
+ /*
+ * Some info has already been found but has problem
+ * in the last btf_ext reloc. Must have to error out.
+ */
+ pr_warn("prog '%s': missing .BTF.ext line info.\n", prog->name);
+ return err;
+ }
+ /* Have problem loading the very first info. Ignore the rest. */
+ pr_warn("prog '%s': missing .BTF.ext line info for the main program, skipping all of .BTF.ext line info.\n",
+ prog->name);
+ }
+ return 0;
+}
+
+static int cmp_relo_by_insn_idx(const void *key, const void *elem)
+{
+ size_t insn_idx = *(const size_t *)key;
+ const struct reloc_desc *relo = elem;
+
+ if (insn_idx == relo->insn_idx)
+ return 0;
+ return insn_idx < relo->insn_idx ? -1 : 1;
+}
+
+static struct reloc_desc *find_prog_insn_relo(const struct bpf_program *prog, size_t insn_idx)
+{
+ return bsearch(&insn_idx, prog->reloc_desc, prog->nr_reloc,
+ sizeof(*prog->reloc_desc), cmp_relo_by_insn_idx);
+}
+
+static int
+bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog,
+ struct bpf_program *prog)
+{
+ size_t sub_insn_idx, insn_idx, new_cnt;
+ struct bpf_program *subprog;
+ struct bpf_insn *insns, *insn;
+ struct reloc_desc *relo;
+ int err;
+
+ err = reloc_prog_func_and_line_info(obj, main_prog, prog);
+ if (err)
+ return err;
+
+ for (insn_idx = 0; insn_idx < prog->sec_insn_cnt; insn_idx++) {
+ insn = &main_prog->insns[prog->sub_insn_off + insn_idx];
+ if (!insn_is_subprog_call(insn))
+ continue;
+
+ relo = find_prog_insn_relo(prog, insn_idx);
+ if (relo && relo->type != RELO_CALL) {
+ pr_warn("prog '%s': unexpected relo for insn #%zu, type %d\n",
+ prog->name, insn_idx, relo->type);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ if (relo) {
+ /* sub-program instruction index is a combination of
+ * an offset of a symbol pointed to by relocation and
+ * call instruction's imm field; for global functions,
+ * call always has imm = -1, but for static functions
+ * relocation is against STT_SECTION and insn->imm
+ * points to a start of a static function
+ */
+ sub_insn_idx = relo->sym_off / BPF_INSN_SZ + insn->imm + 1;
+ } else {
+ /* if subprogram call is to a static function within
+ * the same ELF section, there won't be any relocation
+ * emitted, but it also means there is no additional
+ * offset necessary, insns->imm is relative to
+ * instruction's original position within the section
+ */
+ sub_insn_idx = prog->sec_insn_off + insn_idx + insn->imm + 1;
+ }
+
+ /* we enforce that sub-programs should be in .text section */
+ subprog = find_prog_by_sec_insn(obj, obj->efile.text_shndx, sub_insn_idx);
+ if (!subprog) {
+ pr_warn("prog '%s': no .text section found yet sub-program call exists\n",
+ prog->name);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+
+ /* if it's the first call instruction calling into this
+ * subprogram (meaning this subprog hasn't been processed
+ * yet) within the context of current main program:
+ * - append it at the end of main program's instructions blog;
+ * - process is recursively, while current program is put on hold;
+ * - if that subprogram calls some other not yet processes
+ * subprogram, same thing will happen recursively until
+ * there are no more unprocesses subprograms left to append
+ * and relocate.
+ */
+ if (subprog->sub_insn_off == 0) {
+ subprog->sub_insn_off = main_prog->insns_cnt;
+
+ new_cnt = main_prog->insns_cnt + subprog->insns_cnt;
+ insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns));
+ if (!insns) {
+ pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name);
+ return -ENOMEM;
+ }
+ main_prog->insns = insns;
+ main_prog->insns_cnt = new_cnt;
+
+ memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns,
+ subprog->insns_cnt * sizeof(*insns));
+
+ pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n",
+ main_prog->name, subprog->insns_cnt, subprog->name);
+
+ err = bpf_object__reloc_code(obj, main_prog, subprog);
if (err)
return err;
}
+
+ /* main_prog->insns memory could have been re-allocated, so
+ * calculate pointer again
+ */
+ insn = &main_prog->insns[prog->sub_insn_off + insn_idx];
+ /* calculate correct instruction position within current main
+ * prog; each main prog can have a different set of
+ * subprograms appended (potentially in different order as
+ * well), so position of any subprog can be different for
+ * different main programs */
+ insn->imm = subprog->sub_insn_off - (prog->sub_insn_off + insn_idx) - 1;
+
+ if (relo)
+ relo->processed = true;
+
+ pr_debug("prog '%s': insn #%zu relocated, imm %d points to subprog '%s' (now at %zu offset)\n",
+ prog->name, insn_idx, insn->imm, subprog->name, subprog->sub_insn_off);
}
- zfree(&prog->reloc_desc);
- prog->nr_reloc = 0;
return 0;
}
+/*
+ * Relocate sub-program calls.
+ *
+ * Algorithm operates as follows. Each entry-point BPF program (referred to as
+ * main prog) is processed separately. For each subprog (non-entry functions,
+ * that can be called from either entry progs or other subprogs) gets their
+ * sub_insn_off reset to zero. This serves as indicator that this subprogram
+ * hasn't been yet appended and relocated within current main prog. Once its
+ * relocated, sub_insn_off will point at the position within current main prog
+ * where given subprog was appended. This will further be used to relocate all
+ * the call instructions jumping into this subprog.
+ *
+ * We start with main program and process all call instructions. If the call
+ * is into a subprog that hasn't been processed (i.e., subprog->sub_insn_off
+ * is zero), subprog instructions are appended at the end of main program's
+ * instruction array. Then main program is "put on hold" while we recursively
+ * process newly appended subprogram. If that subprogram calls into another
+ * subprogram that hasn't been appended, new subprogram is appended again to
+ * the *main* prog's instructions (subprog's instructions are always left
+ * untouched, as they need to be in unmodified state for subsequent main progs
+ * and subprog instructions are always sent only as part of a main prog) and
+ * the process continues recursively. Once all the subprogs called from a main
+ * prog or any of its subprogs are appended (and relocated), all their
+ * positions within finalized instructions array are known, so it's easy to
+ * rewrite call instructions with correct relative offsets, corresponding to
+ * desired target subprog.
+ *
+ * Its important to realize that some subprogs might not be called from some
+ * main prog and any of its called/used subprogs. Those will keep their
+ * subprog->sub_insn_off as zero at all times and won't be appended to current
+ * main prog and won't be relocated within the context of current main prog.
+ * They might still be used from other main progs later.
+ *
+ * Visually this process can be shown as below. Suppose we have two main
+ * programs mainA and mainB and BPF object contains three subprogs: subA,
+ * subB, and subC. mainA calls only subA, mainB calls only subC, but subA and
+ * subC both call subB:
+ *
+ * +--------+ +-------+
+ * | v v |
+ * +--+---+ +--+-+-+ +---+--+
+ * | subA | | subB | | subC |
+ * +--+---+ +------+ +---+--+
+ * ^ ^
+ * | |
+ * +---+-------+ +------+----+
+ * | mainA | | mainB |
+ * +-----------+ +-----------+
+ *
+ * We'll start relocating mainA, will find subA, append it and start
+ * processing sub A recursively:
+ *
+ * +-----------+------+
+ * | mainA | subA |
+ * +-----------+------+
+ *
+ * At this point we notice that subB is used from subA, so we append it and
+ * relocate (there are no further subcalls from subB):
+ *
+ * +-----------+------+------+
+ * | mainA | subA | subB |
+ * +-----------+------+------+
+ *
+ * At this point, we relocate subA calls, then go one level up and finish with
+ * relocatin mainA calls. mainA is done.
+ *
+ * For mainB process is similar but results in different order. We start with
+ * mainB and skip subA and subB, as mainB never calls them (at least
+ * directly), but we see subC is needed, so we append and start processing it:
+ *
+ * +-----------+------+
+ * | mainB | subC |
+ * +-----------+------+
+ * Now we see subC needs subB, so we go back to it, append and relocate it:
+ *
+ * +-----------+------+------+
+ * | mainB | subC | subB |
+ * +-----------+------+------+
+ *
+ * At this point we unwind recursion, relocate calls in subC, then in mainB.
+ */
+static int
+bpf_object__relocate_calls(struct bpf_object *obj, struct bpf_program *prog)
+{
+ struct bpf_program *subprog;
+ int i, j, err;
+
+ /* mark all subprogs as not relocated (yet) within the context of
+ * current main program
+ */
+ for (i = 0; i < obj->nr_programs; i++) {
+ subprog = &obj->programs[i];
+ if (!prog_is_subprog(obj, subprog))
+ continue;
+
+ subprog->sub_insn_off = 0;
+ for (j = 0; j < subprog->nr_reloc; j++)
+ if (subprog->reloc_desc[j].type == RELO_CALL)
+ subprog->reloc_desc[j].processed = false;
+ }
+
+ err = bpf_object__reloc_code(obj, prog, prog);
+ if (err)
+ return err;
+
+
+ return 0;
+}
static int
-bpf_object__relocate(struct bpf_object *obj)
+bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
{
struct bpf_program *prog;
size_t i;
int err;
- for (i = 0; i < obj->nr_programs; i++) {
- prog = &obj->programs[i];
-
- err = bpf_program__relocate(prog, obj);
+ if (obj->btf_ext) {
+ err = bpf_object__relocate_core(obj, targ_btf_path);
if (err) {
- pr_warning("failed to relocate '%s'\n",
- prog->section_name);
+ pr_warn("failed to perform CO-RE relocations: %d\n",
+ err);
return err;
}
+ }
+ /* relocate data references first for all programs and sub-programs,
+ * as they don't change relative to code locations, so subsequent
+ * subprogram processing won't need to re-calculate any of them
+ */
+ for (i = 0; i < obj->nr_programs; i++) {
+ prog = &obj->programs[i];
+ err = bpf_object__relocate_data(obj, prog);
+ if (err) {
+ pr_warn("prog '%s': failed to relocate data references: %d\n",
+ prog->name, err);
+ return err;
+ }
+ }
+ /* now relocate subprogram calls and append used subprograms to main
+ * programs; each copy of subprogram code needs to be relocated
+ * differently for each main program, because its code location might
+ * have changed
+ */
+ for (i = 0; i < obj->nr_programs; i++) {
+ prog = &obj->programs[i];
+ /* sub-program's sub-calls are relocated within the context of
+ * its main program only
+ */
+ if (prog_is_subprog(obj, prog))
+ continue;
+
+ err = bpf_object__relocate_calls(obj, prog);
+ if (err) {
+ pr_warn("prog '%s': failed to relocate calls: %d\n",
+ prog->name, err);
+ return err;
+ }
+ }
+ /* free up relocation descriptors */
+ for (i = 0; i < obj->nr_programs; i++) {
+ prog = &obj->programs[i];
+ zfree(&prog->reloc_desc);
+ prog->nr_reloc = 0;
}
return 0;
}
-static int bpf_object__collect_reloc(struct bpf_object *obj)
+static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
+ GElf_Shdr *shdr, Elf_Data *data);
+
+static int bpf_object__collect_map_relos(struct bpf_object *obj,
+ GElf_Shdr *shdr, Elf_Data *data)
{
- int i, err;
+ const int bpf_ptr_sz = 8, host_ptr_sz = sizeof(void *);
+ int i, j, nrels, new_sz;
+ const struct btf_var_secinfo *vi = NULL;
+ const struct btf_type *sec, *var, *def;
+ struct bpf_map *map = NULL, *targ_map;
+ const struct btf_member *member;
+ const char *name, *mname;
+ Elf_Data *symbols;
+ unsigned int moff;
+ GElf_Sym sym;
+ GElf_Rel rel;
+ void *tmp;
- if (!obj_elf_valid(obj)) {
- pr_warning("Internal error: elf object is closed\n");
- return -LIBBPF_ERRNO__INTERNAL;
- }
+ if (!obj->efile.btf_maps_sec_btf_id || !obj->btf)
+ return -EINVAL;
+ sec = btf__type_by_id(obj->btf, obj->efile.btf_maps_sec_btf_id);
+ if (!sec)
+ return -EINVAL;
- for (i = 0; i < obj->efile.nr_reloc; i++) {
- GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
- Elf_Data *data = obj->efile.reloc[i].data;
- int idx = shdr->sh_info;
- struct bpf_program *prog;
-
- if (shdr->sh_type != SHT_REL) {
- pr_warning("internal error at %d\n", __LINE__);
- return -LIBBPF_ERRNO__INTERNAL;
+ symbols = obj->efile.symbols;
+ nrels = shdr->sh_size / shdr->sh_entsize;
+ for (i = 0; i < nrels; i++) {
+ if (!gelf_getrel(data, i, &rel)) {
+ pr_warn(".maps relo #%d: failed to get ELF relo\n", i);
+ return -LIBBPF_ERRNO__FORMAT;
}
-
- prog = bpf_object__find_prog_by_idx(obj, idx);
- if (!prog) {
- pr_warning("relocation failed: no section(%d)\n", idx);
+ if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+ pr_warn(".maps relo #%d: symbol %zx not found\n",
+ i, (size_t)GELF_R_SYM(rel.r_info));
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ name = elf_sym_str(obj, sym.st_name) ?: "<?>";
+ if (sym.st_shndx != obj->efile.btf_maps_shndx) {
+ pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n",
+ i, name);
return -LIBBPF_ERRNO__RELOC;
}
- err = bpf_program__collect_reloc(prog,
- shdr, data,
- obj);
+ pr_debug(".maps relo #%d: for %zd value %zd rel.r_offset %zu name %d ('%s')\n",
+ i, (ssize_t)(rel.r_info >> 32), (size_t)sym.st_value,
+ (size_t)rel.r_offset, sym.st_name, name);
+
+ for (j = 0; j < obj->nr_maps; j++) {
+ map = &obj->maps[j];
+ if (map->sec_idx != obj->efile.btf_maps_shndx)
+ continue;
+
+ vi = btf_var_secinfos(sec) + map->btf_var_idx;
+ if (vi->offset <= rel.r_offset &&
+ rel.r_offset + bpf_ptr_sz <= vi->offset + vi->size)
+ break;
+ }
+ if (j == obj->nr_maps) {
+ pr_warn(".maps relo #%d: cannot find map '%s' at rel.r_offset %zu\n",
+ i, name, (size_t)rel.r_offset);
+ return -EINVAL;
+ }
+
+ if (!bpf_map_type__is_map_in_map(map->def.type))
+ return -EINVAL;
+ if (map->def.type == BPF_MAP_TYPE_HASH_OF_MAPS &&
+ map->def.key_size != sizeof(int)) {
+ pr_warn(".maps relo #%d: hash-of-maps '%s' should have key size %zu.\n",
+ i, map->name, sizeof(int));
+ return -EINVAL;
+ }
+
+ targ_map = bpf_object__find_map_by_name(obj, name);
+ if (!targ_map)
+ return -ESRCH;
+
+ var = btf__type_by_id(obj->btf, vi->type);
+ def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
+ if (btf_vlen(def) == 0)
+ return -EINVAL;
+ member = btf_members(def) + btf_vlen(def) - 1;
+ mname = btf__name_by_offset(obj->btf, member->name_off);
+ if (strcmp(mname, "values"))
+ return -EINVAL;
+
+ moff = btf_member_bit_offset(def, btf_vlen(def) - 1) / 8;
+ if (rel.r_offset - vi->offset < moff)
+ return -EINVAL;
+
+ moff = rel.r_offset - vi->offset - moff;
+ /* here we use BPF pointer size, which is always 64 bit, as we
+ * are parsing ELF that was built for BPF target
+ */
+ if (moff % bpf_ptr_sz)
+ return -EINVAL;
+ moff /= bpf_ptr_sz;
+ if (moff >= map->init_slots_sz) {
+ new_sz = moff + 1;
+ tmp = libbpf_reallocarray(map->init_slots, new_sz, host_ptr_sz);
+ if (!tmp)
+ return -ENOMEM;
+ map->init_slots = tmp;
+ memset(map->init_slots + map->init_slots_sz, 0,
+ (new_sz - map->init_slots_sz) * host_ptr_sz);
+ map->init_slots_sz = new_sz;
+ }
+ map->init_slots[moff] = targ_map;
+
+ pr_debug(".maps relo #%d: map '%s' slot [%d] points to map '%s'\n",
+ i, map->name, moff, name);
+ }
+
+ return 0;
+}
+
+static int cmp_relocs(const void *_a, const void *_b)
+{
+ const struct reloc_desc *a = _a;
+ const struct reloc_desc *b = _b;
+
+ if (a->insn_idx != b->insn_idx)
+ return a->insn_idx < b->insn_idx ? -1 : 1;
+
+ /* no two relocations should have the same insn_idx, but ... */
+ if (a->type != b->type)
+ return a->type < b->type ? -1 : 1;
+
+ return 0;
+}
+
+static int bpf_object__collect_relos(struct bpf_object *obj)
+{
+ int i, err;
+
+ for (i = 0; i < obj->efile.nr_reloc_sects; i++) {
+ GElf_Shdr *shdr = &obj->efile.reloc_sects[i].shdr;
+ Elf_Data *data = obj->efile.reloc_sects[i].data;
+ int idx = shdr->sh_info;
+
+ if (shdr->sh_type != SHT_REL) {
+ pr_warn("internal error at %d\n", __LINE__);
+ return -LIBBPF_ERRNO__INTERNAL;
+ }
+
+ if (idx == obj->efile.st_ops_shndx)
+ err = bpf_object__collect_st_ops_relos(obj, shdr, data);
+ else if (idx == obj->efile.btf_maps_shndx)
+ err = bpf_object__collect_map_relos(obj, shdr, data);
+ else
+ err = bpf_object__collect_prog_relos(obj, shdr, data);
if (err)
return err;
+ }
+
+ for (i = 0; i < obj->nr_programs; i++) {
+ struct bpf_program *p = &obj->programs[i];
+
+ if (!p->nr_reloc)
+ continue;
+
+ qsort(p->reloc_desc, p->nr_reloc, sizeof(*p->reloc_desc), cmp_relocs);
+ }
+ return 0;
+}
+
+static bool insn_is_helper_call(struct bpf_insn *insn, enum bpf_func_id *func_id)
+{
+ if (BPF_CLASS(insn->code) == BPF_JMP &&
+ BPF_OP(insn->code) == BPF_CALL &&
+ BPF_SRC(insn->code) == BPF_K &&
+ insn->src_reg == 0 &&
+ insn->dst_reg == 0) {
+ *func_id = insn->imm;
+ return true;
+ }
+ return false;
+}
+
+static int bpf_object__sanitize_prog(struct bpf_object* obj, struct bpf_program *prog)
+{
+ struct bpf_insn *insn = prog->insns;
+ enum bpf_func_id func_id;
+ int i;
+
+ for (i = 0; i < prog->insns_cnt; i++, insn++) {
+ if (!insn_is_helper_call(insn, &func_id))
+ continue;
+
+ /* on kernels that don't yet support
+ * bpf_probe_read_{kernel,user}[_str] helpers, fall back
+ * to bpf_probe_read() which works well for old kernels
+ */
+ switch (func_id) {
+ case BPF_FUNC_probe_read_kernel:
+ case BPF_FUNC_probe_read_user:
+ if (!kernel_supports(FEAT_PROBE_READ_KERN))
+ insn->imm = BPF_FUNC_probe_read;
+ break;
+ case BPF_FUNC_probe_read_kernel_str:
+ case BPF_FUNC_probe_read_user_str:
+ if (!kernel_supports(FEAT_PROBE_READ_KERN))
+ insn->imm = BPF_FUNC_probe_read_str;
+ break;
+ default:
+ break;
+ }
}
return 0;
}
static int
-load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type,
- const char *name, struct bpf_insn *insns, int insns_cnt,
- char *license, u32 kern_version, int *pfd, int prog_ifindex)
+load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
+ char *license, __u32 kern_version, int *pfd)
{
struct bpf_load_program_attr load_attr;
char *cp, errmsg[STRERR_BUFSIZE];
- char *log_buf;
- int ret;
+ size_t log_buf_size = 0;
+ char *log_buf = NULL;
+ int btf_fd, ret;
+
+ if (!insns || !insns_cnt)
+ return -EINVAL;
memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
- load_attr.prog_type = type;
- load_attr.expected_attach_type = expected_attach_type;
- load_attr.name = name;
+ load_attr.prog_type = prog->type;
+ /* old kernels might not support specifying expected_attach_type */
+ if (!kernel_supports(FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
+ prog->sec_def->is_exp_attach_type_optional)
+ load_attr.expected_attach_type = 0;
+ else
+ load_attr.expected_attach_type = prog->expected_attach_type;
+ if (kernel_supports(FEAT_PROG_NAME))
+ load_attr.name = prog->name;
load_attr.insns = insns;
load_attr.insns_cnt = insns_cnt;
load_attr.license = license;
- load_attr.kern_version = kern_version;
- load_attr.prog_ifindex = prog_ifindex;
+ if (prog->type == BPF_PROG_TYPE_STRUCT_OPS ||
+ prog->type == BPF_PROG_TYPE_LSM) {
+ load_attr.attach_btf_id = prog->attach_btf_id;
+ } else if (prog->type == BPF_PROG_TYPE_TRACING ||
+ prog->type == BPF_PROG_TYPE_EXT) {
+ load_attr.attach_prog_fd = prog->attach_prog_fd;
+ load_attr.attach_btf_id = prog->attach_btf_id;
+ } else {
+ load_attr.kern_version = kern_version;
+ load_attr.prog_ifindex = prog->prog_ifindex;
+ }
+ /* specify func_info/line_info only if kernel supports them */
+ btf_fd = bpf_object__btf_fd(prog->obj);
+ if (btf_fd >= 0 && kernel_supports(FEAT_BTF_FUNC)) {
+ load_attr.prog_btf_fd = btf_fd;
+ load_attr.func_info = prog->func_info;
+ load_attr.func_info_rec_size = prog->func_info_rec_size;
+ load_attr.func_info_cnt = prog->func_info_cnt;
+ load_attr.line_info = prog->line_info;
+ load_attr.line_info_rec_size = prog->line_info_rec_size;
+ load_attr.line_info_cnt = prog->line_info_cnt;
+ }
+ load_attr.log_level = prog->log_level;
+ load_attr.prog_flags = prog->prog_flags;
- if (!load_attr.insns || !load_attr.insns_cnt)
- return -EINVAL;
+retry_load:
+ if (log_buf_size) {
+ log_buf = malloc(log_buf_size);
+ if (!log_buf)
+ return -ENOMEM;
- log_buf = malloc(BPF_LOG_BUF_SIZE);
- if (!log_buf)
- pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
+ *log_buf = 0;
+ }
- ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE);
+ ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
if (ret >= 0) {
+ if (log_buf && load_attr.log_level)
+ pr_debug("verifier log:\n%s", log_buf);
+
+ if (prog->obj->rodata_map_idx >= 0 &&
+ kernel_supports(FEAT_PROG_BIND_MAP)) {
+ struct bpf_map *rodata_map =
+ &prog->obj->maps[prog->obj->rodata_map_idx];
+
+ if (bpf_prog_bind_map(ret, bpf_map__fd(rodata_map), NULL)) {
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warn("prog '%s': failed to bind .rodata map: %s\n",
+ prog->name, cp);
+ /* Don't fail hard if can't bind rodata. */
+ }
+ }
+
*pfd = ret;
ret = 0;
goto out;
}
- ret = -LIBBPF_ERRNO__LOAD;
- cp = str_error(errno, errmsg, sizeof(errmsg));
- pr_warning("load bpf program failed: %s\n", cp);
+ if (!log_buf || errno == ENOSPC) {
+ log_buf_size = max((size_t)BPF_LOG_BUF_SIZE,
+ log_buf_size << 1);
+
+ free(log_buf);
+ goto retry_load;
+ }
+ ret = errno ? -errno : -LIBBPF_ERRNO__LOAD;
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warn("load bpf program failed: %s\n", cp);
+ pr_perm_msg(ret);
if (log_buf && log_buf[0] != '\0') {
ret = -LIBBPF_ERRNO__VERIFY;
- pr_warning("-- BEGIN DUMP LOG ---\n");
- pr_warning("\n%s\n", log_buf);
- pr_warning("-- END LOG --\n");
+ pr_warn("-- BEGIN DUMP LOG ---\n");
+ pr_warn("\n%s\n", log_buf);
+ pr_warn("-- END LOG --\n");
} else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
- pr_warning("Program too large (%zu insns), at most %d insns\n",
- load_attr.insns_cnt, BPF_MAXINSNS);
+ pr_warn("Program too large (%zu insns), at most %d insns\n",
+ load_attr.insns_cnt, BPF_MAXINSNS);
ret = -LIBBPF_ERRNO__PROG2BIG;
- } else {
+ } else if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
/* Wrong program type? */
- if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
- int fd;
+ int fd;
- load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
- load_attr.expected_attach_type = 0;
- fd = bpf_load_program_xattr(&load_attr, NULL, 0);
- if (fd >= 0) {
- close(fd);
- ret = -LIBBPF_ERRNO__PROGTYPE;
- goto out;
- }
+ load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
+ load_attr.expected_attach_type = 0;
+ fd = bpf_load_program_xattr(&load_attr, NULL, 0);
+ if (fd >= 0) {
+ close(fd);
+ ret = -LIBBPF_ERRNO__PROGTYPE;
+ goto out;
}
-
- if (log_buf)
- ret = -LIBBPF_ERRNO__KVER;
}
out:
@@ -1383,22 +6816,36 @@
return ret;
}
-static int
-bpf_program__load(struct bpf_program *prog,
- char *license, u32 kern_version)
+static int libbpf_find_attach_btf_id(struct bpf_program *prog);
+
+int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
{
- int err = 0, fd, i;
+ int err = 0, fd, i, btf_id;
+
+ if (prog->obj->loaded) {
+ pr_warn("prog '%s': can't load after object was loaded\n", prog->name);
+ return -EINVAL;
+ }
+
+ if ((prog->type == BPF_PROG_TYPE_TRACING ||
+ prog->type == BPF_PROG_TYPE_LSM ||
+ prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
+ btf_id = libbpf_find_attach_btf_id(prog);
+ if (btf_id <= 0)
+ return btf_id;
+ prog->attach_btf_id = btf_id;
+ }
if (prog->instances.nr < 0 || !prog->instances.fds) {
if (prog->preprocessor) {
- pr_warning("Internal error: can't load program '%s'\n",
- prog->section_name);
+ pr_warn("Internal error: can't load program '%s'\n",
+ prog->name);
return -LIBBPF_ERRNO__INTERNAL;
}
prog->instances.fds = malloc(sizeof(int));
if (!prog->instances.fds) {
- pr_warning("Not enough memory for BPF fds\n");
+ pr_warn("Not enough memory for BPF fds\n");
return -ENOMEM;
}
prog->instances.nr = 1;
@@ -1407,13 +6854,11 @@
if (!prog->preprocessor) {
if (prog->instances.nr != 1) {
- pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
- prog->section_name, prog->instances.nr);
+ pr_warn("prog '%s': inconsistent nr(%d) != 1\n",
+ prog->name, prog->instances.nr);
}
- err = load_program(prog->type, prog->expected_attach_type,
- prog->name, prog->insns, prog->insns_cnt,
- license, kern_version, &fd,
- prog->prog_ifindex);
+ err = load_program(prog, prog->insns, prog->insns_cnt,
+ license, kern_ver, &fd);
if (!err)
prog->instances.fds[0] = fd;
goto out;
@@ -1423,33 +6868,29 @@
struct bpf_prog_prep_result result;
bpf_program_prep_t preprocessor = prog->preprocessor;
- bzero(&result, sizeof(result));
+ memset(&result, 0, sizeof(result));
err = preprocessor(prog, i, prog->insns,
prog->insns_cnt, &result);
if (err) {
- pr_warning("Preprocessing the %dth instance of program '%s' failed\n",
- i, prog->section_name);
+ pr_warn("Preprocessing the %dth instance of program '%s' failed\n",
+ i, prog->name);
goto out;
}
if (!result.new_insn_ptr || !result.new_insn_cnt) {
pr_debug("Skip loading the %dth instance of program '%s'\n",
- i, prog->section_name);
+ i, prog->name);
prog->instances.fds[i] = -1;
if (result.pfd)
*result.pfd = -1;
continue;
}
- err = load_program(prog->type, prog->expected_attach_type,
- prog->name, result.new_insn_ptr,
- result.new_insn_cnt,
- license, kern_version, &fd,
- prog->prog_ifindex);
-
+ err = load_program(prog, result.new_insn_ptr,
+ result.new_insn_cnt, license, kern_ver, &fd);
if (err) {
- pr_warning("Loading the %dth instance of program '%s' failed\n",
- i, prog->section_name);
+ pr_warn("Loading the %dth instance of program '%s' failed\n",
+ i, prog->name);
goto out;
}
@@ -1459,117 +6900,140 @@
}
out:
if (err)
- pr_warning("failed to load program '%s'\n",
- prog->section_name);
+ pr_warn("failed to load program '%s'\n", prog->name);
zfree(&prog->insns);
prog->insns_cnt = 0;
return err;
}
-static bool bpf_program__is_function_storage(struct bpf_program *prog,
- struct bpf_object *obj)
-{
- return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls;
-}
-
static int
-bpf_object__load_progs(struct bpf_object *obj)
+bpf_object__load_progs(struct bpf_object *obj, int log_level)
{
+ struct bpf_program *prog;
size_t i;
int err;
for (i = 0; i < obj->nr_programs; i++) {
- if (bpf_program__is_function_storage(&obj->programs[i], obj))
+ prog = &obj->programs[i];
+ err = bpf_object__sanitize_prog(obj, prog);
+ if (err)
+ return err;
+ }
+
+ for (i = 0; i < obj->nr_programs; i++) {
+ prog = &obj->programs[i];
+ if (prog_is_subprog(obj, prog))
continue;
- err = bpf_program__load(&obj->programs[i],
- obj->license,
- obj->kern_version);
+ if (!prog->load) {
+ pr_debug("prog '%s': skipped loading\n", prog->name);
+ continue;
+ }
+ prog->log_level |= log_level;
+ err = bpf_program__load(prog, obj->license, obj->kern_version);
if (err)
return err;
}
return 0;
}
-static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
-{
- switch (type) {
- case BPF_PROG_TYPE_SOCKET_FILTER:
- case BPF_PROG_TYPE_SCHED_CLS:
- case BPF_PROG_TYPE_SCHED_ACT:
- case BPF_PROG_TYPE_XDP:
- case BPF_PROG_TYPE_CGROUP_SKB:
- case BPF_PROG_TYPE_CGROUP_SOCK:
- case BPF_PROG_TYPE_LWT_IN:
- case BPF_PROG_TYPE_LWT_OUT:
- case BPF_PROG_TYPE_LWT_XMIT:
- case BPF_PROG_TYPE_LWT_SEG6LOCAL:
- case BPF_PROG_TYPE_SOCK_OPS:
- case BPF_PROG_TYPE_SK_SKB:
- case BPF_PROG_TYPE_CGROUP_DEVICE:
- case BPF_PROG_TYPE_SK_MSG:
- case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
- case BPF_PROG_TYPE_LIRC_MODE2:
- case BPF_PROG_TYPE_SK_REUSEPORT:
- return false;
- case BPF_PROG_TYPE_UNSPEC:
- case BPF_PROG_TYPE_KPROBE:
- case BPF_PROG_TYPE_TRACEPOINT:
- case BPF_PROG_TYPE_PERF_EVENT:
- case BPF_PROG_TYPE_RAW_TRACEPOINT:
- default:
- return true;
- }
-}
-
-static int bpf_object__validate(struct bpf_object *obj, bool needs_kver)
-{
- if (needs_kver && obj->kern_version == 0) {
- pr_warning("%s doesn't provide kernel version\n",
- obj->path);
- return -LIBBPF_ERRNO__KVERSION;
- }
- return 0;
-}
+static const struct bpf_sec_def *find_sec_def(const char *sec_name);
static struct bpf_object *
-__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
- bool needs_kver)
+__bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
+ const struct bpf_object_open_opts *opts)
{
+ const char *obj_name, *kconfig;
+ struct bpf_program *prog;
struct bpf_object *obj;
+ char tmp_name[64];
int err;
if (elf_version(EV_CURRENT) == EV_NONE) {
- pr_warning("failed to init libelf for %s\n", path);
+ pr_warn("failed to init libelf for %s\n",
+ path ? : "(mem buf)");
return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
}
- obj = bpf_object__new(path, obj_buf, obj_buf_sz);
+ if (!OPTS_VALID(opts, bpf_object_open_opts))
+ return ERR_PTR(-EINVAL);
+
+ obj_name = OPTS_GET(opts, object_name, NULL);
+ if (obj_buf) {
+ if (!obj_name) {
+ snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
+ (unsigned long)obj_buf,
+ (unsigned long)obj_buf_sz);
+ obj_name = tmp_name;
+ }
+ path = obj_name;
+ pr_debug("loading object '%s' from buffer\n", obj_name);
+ }
+
+ obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
if (IS_ERR(obj))
return obj;
- CHECK_ERR(bpf_object__elf_init(obj), err, out);
- CHECK_ERR(bpf_object__check_endianness(obj), err, out);
- CHECK_ERR(bpf_object__elf_collect(obj), err, out);
- CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
- CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out);
+ kconfig = OPTS_GET(opts, kconfig, NULL);
+ if (kconfig) {
+ obj->kconfig = strdup(kconfig);
+ if (!obj->kconfig) {
+ err = -ENOMEM;
+ goto out;
+ }
+ }
+ err = bpf_object__elf_init(obj);
+ err = err ? : bpf_object__check_endianness(obj);
+ err = err ? : bpf_object__elf_collect(obj);
+ err = err ? : bpf_object__collect_externs(obj);
+ err = err ? : bpf_object__finalize_btf(obj);
+ err = err ? : bpf_object__init_maps(obj, opts);
+ err = err ? : bpf_object__collect_relos(obj);
+ if (err)
+ goto out;
bpf_object__elf_finish(obj);
+
+ bpf_object__for_each_program(prog, obj) {
+ prog->sec_def = find_sec_def(prog->sec_name);
+ if (!prog->sec_def)
+ /* couldn't guess, but user might manually specify */
+ continue;
+
+ if (prog->sec_def->is_sleepable)
+ prog->prog_flags |= BPF_F_SLEEPABLE;
+ bpf_program__set_type(prog, prog->sec_def->prog_type);
+ bpf_program__set_expected_attach_type(prog,
+ prog->sec_def->expected_attach_type);
+
+ if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING ||
+ prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
+ prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
+ }
+
return obj;
out:
bpf_object__close(obj);
return ERR_PTR(err);
}
-struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
+static struct bpf_object *
+__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
{
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .relaxed_maps = flags & MAPS_RELAX_COMPAT,
+ );
+
/* param validation */
if (!attr->file)
return NULL;
pr_debug("loading %s\n", attr->file);
+ return __bpf_object__open(attr->file, NULL, 0, &opts);
+}
- return __bpf_object__open(attr->file, NULL, 0,
- bpf_prog_type__needs_kver(attr->prog_type));
+struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
+{
+ return __bpf_object__open_xattr(attr, 0);
}
struct bpf_object *bpf_object__open(const char *path)
@@ -1582,27 +7046,42 @@
return bpf_object__open_xattr(&attr);
}
-struct bpf_object *bpf_object__open_buffer(void *obj_buf,
- size_t obj_buf_sz,
- const char *name)
+struct bpf_object *
+bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts)
{
- char tmp_name[64];
+ if (!path)
+ return ERR_PTR(-EINVAL);
- /* param validation */
- if (!obj_buf || obj_buf_sz <= 0)
+ pr_debug("loading %s\n", path);
+
+ return __bpf_object__open(path, NULL, 0, opts);
+}
+
+struct bpf_object *
+bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
+ const struct bpf_object_open_opts *opts)
+{
+ if (!obj_buf || obj_buf_sz == 0)
+ return ERR_PTR(-EINVAL);
+
+ return __bpf_object__open(NULL, obj_buf, obj_buf_sz, opts);
+}
+
+struct bpf_object *
+bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
+ const char *name)
+{
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
+ .object_name = name,
+ /* wrong default, but backwards-compatible */
+ .relaxed_maps = true,
+ );
+
+ /* returning NULL is wrong, but backwards-compatible */
+ if (!obj_buf || obj_buf_sz == 0)
return NULL;
- if (!name) {
- snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
- (unsigned long)obj_buf,
- (unsigned long)obj_buf_sz);
- tmp_name[sizeof(tmp_name) - 1] = '\0';
- name = tmp_name;
- }
- pr_debug("loading object '%s' from buffer\n",
- name);
-
- return __bpf_object__open(name, obj_buf, obj_buf_sz, true);
+ return bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
}
int bpf_object__unload(struct bpf_object *obj)
@@ -1612,8 +7091,11 @@
if (!obj)
return -EINVAL;
- for (i = 0; i < obj->nr_maps; i++)
+ for (i = 0; i < obj->nr_maps; i++) {
zclose(obj->maps[i].fd);
+ if (obj->maps[i].st_ops)
+ zfree(&obj->maps[i].st_ops->kern_vdata);
+ }
for (i = 0; i < obj->nr_programs; i++)
bpf_program__unload(&obj->programs[i]);
@@ -1621,28 +7103,294 @@
return 0;
}
-int bpf_object__load(struct bpf_object *obj)
+static int bpf_object__sanitize_maps(struct bpf_object *obj)
{
- int err;
+ struct bpf_map *m;
+ bpf_object__for_each_map(m, obj) {
+ if (!bpf_map__is_internal(m))
+ continue;
+ if (!kernel_supports(FEAT_GLOBAL_DATA)) {
+ pr_warn("kernel doesn't support global data\n");
+ return -ENOTSUP;
+ }
+ if (!kernel_supports(FEAT_ARRAY_MMAP))
+ m->def.map_flags ^= BPF_F_MMAPABLE;
+ }
+
+ return 0;
+}
+
+static int bpf_object__read_kallsyms_file(struct bpf_object *obj)
+{
+ char sym_type, sym_name[500];
+ unsigned long long sym_addr;
+ struct extern_desc *ext;
+ int ret, err = 0;
+ FILE *f;
+
+ f = fopen("/proc/kallsyms", "r");
+ if (!f) {
+ err = -errno;
+ pr_warn("failed to open /proc/kallsyms: %d\n", err);
+ return err;
+ }
+
+ while (true) {
+ ret = fscanf(f, "%llx %c %499s%*[^\n]\n",
+ &sym_addr, &sym_type, sym_name);
+ if (ret == EOF && feof(f))
+ break;
+ if (ret != 3) {
+ pr_warn("failed to read kallsyms entry: %d\n", ret);
+ err = -EINVAL;
+ goto out;
+ }
+
+ ext = find_extern_by_name(obj, sym_name);
+ if (!ext || ext->type != EXT_KSYM)
+ continue;
+
+ if (ext->is_set && ext->ksym.addr != sym_addr) {
+ pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n",
+ sym_name, ext->ksym.addr, sym_addr);
+ err = -EINVAL;
+ goto out;
+ }
+ if (!ext->is_set) {
+ ext->is_set = true;
+ ext->ksym.addr = sym_addr;
+ pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr);
+ }
+ }
+
+out:
+ fclose(f);
+ return err;
+}
+
+static int bpf_object__resolve_ksyms_btf_id(struct bpf_object *obj)
+{
+ struct extern_desc *ext;
+ int i, id;
+
+ for (i = 0; i < obj->nr_extern; i++) {
+ const struct btf_type *targ_var, *targ_type;
+ __u32 targ_type_id, local_type_id;
+ const char *targ_var_name;
+ int ret;
+
+ ext = &obj->externs[i];
+ if (ext->type != EXT_KSYM || !ext->ksym.type_id)
+ continue;
+
+ id = btf__find_by_name_kind(obj->btf_vmlinux, ext->name,
+ BTF_KIND_VAR);
+ if (id <= 0) {
+ pr_warn("extern (ksym) '%s': failed to find BTF ID in vmlinux BTF.\n",
+ ext->name);
+ return -ESRCH;
+ }
+
+ /* find local type_id */
+ local_type_id = ext->ksym.type_id;
+
+ /* find target type_id */
+ targ_var = btf__type_by_id(obj->btf_vmlinux, id);
+ targ_var_name = btf__name_by_offset(obj->btf_vmlinux,
+ targ_var->name_off);
+ targ_type = skip_mods_and_typedefs(obj->btf_vmlinux,
+ targ_var->type,
+ &targ_type_id);
+
+ ret = bpf_core_types_are_compat(obj->btf, local_type_id,
+ obj->btf_vmlinux, targ_type_id);
+ if (ret <= 0) {
+ const struct btf_type *local_type;
+ const char *targ_name, *local_name;
+
+ local_type = btf__type_by_id(obj->btf, local_type_id);
+ local_name = btf__name_by_offset(obj->btf,
+ local_type->name_off);
+ targ_name = btf__name_by_offset(obj->btf_vmlinux,
+ targ_type->name_off);
+
+ pr_warn("extern (ksym) '%s': incompatible types, expected [%d] %s %s, but kernel has [%d] %s %s\n",
+ ext->name, local_type_id,
+ btf_kind_str(local_type), local_name, targ_type_id,
+ btf_kind_str(targ_type), targ_name);
+ return -EINVAL;
+ }
+
+ ext->is_set = true;
+ ext->ksym.vmlinux_btf_id = id;
+ pr_debug("extern (ksym) '%s': resolved to [%d] %s %s\n",
+ ext->name, id, btf_kind_str(targ_var), targ_var_name);
+ }
+ return 0;
+}
+
+static int bpf_object__resolve_externs(struct bpf_object *obj,
+ const char *extra_kconfig)
+{
+ bool need_config = false, need_kallsyms = false;
+ bool need_vmlinux_btf = false;
+ struct extern_desc *ext;
+ void *kcfg_data = NULL;
+ int err, i;
+
+ if (obj->nr_extern == 0)
+ return 0;
+
+ if (obj->kconfig_map_idx >= 0)
+ kcfg_data = obj->maps[obj->kconfig_map_idx].mmaped;
+
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+
+ if (ext->type == EXT_KCFG &&
+ strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) {
+ void *ext_val = kcfg_data + ext->kcfg.data_off;
+ __u32 kver = get_kernel_version();
+
+ if (!kver) {
+ pr_warn("failed to get kernel version\n");
+ return -EINVAL;
+ }
+ err = set_kcfg_value_num(ext, ext_val, kver);
+ if (err)
+ return err;
+ pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver);
+ } else if (ext->type == EXT_KCFG &&
+ strncmp(ext->name, "CONFIG_", 7) == 0) {
+ need_config = true;
+ } else if (ext->type == EXT_KSYM) {
+ if (ext->ksym.type_id)
+ need_vmlinux_btf = true;
+ else
+ need_kallsyms = true;
+ } else {
+ pr_warn("unrecognized extern '%s'\n", ext->name);
+ return -EINVAL;
+ }
+ }
+ if (need_config && extra_kconfig) {
+ err = bpf_object__read_kconfig_mem(obj, extra_kconfig, kcfg_data);
+ if (err)
+ return -EINVAL;
+ need_config = false;
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+ if (ext->type == EXT_KCFG && !ext->is_set) {
+ need_config = true;
+ break;
+ }
+ }
+ }
+ if (need_config) {
+ err = bpf_object__read_kconfig_file(obj, kcfg_data);
+ if (err)
+ return -EINVAL;
+ }
+ if (need_kallsyms) {
+ err = bpf_object__read_kallsyms_file(obj);
+ if (err)
+ return -EINVAL;
+ }
+ if (need_vmlinux_btf) {
+ err = bpf_object__resolve_ksyms_btf_id(obj);
+ if (err)
+ return -EINVAL;
+ }
+ for (i = 0; i < obj->nr_extern; i++) {
+ ext = &obj->externs[i];
+
+ if (!ext->is_set && !ext->is_weak) {
+ pr_warn("extern %s (strong) not resolved\n", ext->name);
+ return -ESRCH;
+ } else if (!ext->is_set) {
+ pr_debug("extern %s (weak) not resolved, defaulting to zero\n",
+ ext->name);
+ }
+ }
+
+ return 0;
+}
+
+int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
+{
+ struct bpf_object *obj;
+ int err, i;
+
+ if (!attr)
+ return -EINVAL;
+ obj = attr->obj;
if (!obj)
return -EINVAL;
if (obj->loaded) {
- pr_warning("object should not be loaded twice\n");
+ pr_warn("object '%s': load can't be attempted twice\n", obj->name);
return -EINVAL;
}
- obj->loaded = true;
+ err = bpf_object__probe_loading(obj);
+ err = err ? : bpf_object__load_vmlinux_btf(obj);
+ err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
+ err = err ? : bpf_object__sanitize_and_load_btf(obj);
+ err = err ? : bpf_object__sanitize_maps(obj);
+ err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
+ err = err ? : bpf_object__create_maps(obj);
+ err = err ? : bpf_object__relocate(obj, attr->target_btf_path);
+ err = err ? : bpf_object__load_progs(obj, attr->log_level);
- CHECK_ERR(bpf_object__create_maps(obj), err, out);
- CHECK_ERR(bpf_object__relocate(obj), err, out);
- CHECK_ERR(bpf_object__load_progs(obj), err, out);
+ btf__free(obj->btf_vmlinux);
+ obj->btf_vmlinux = NULL;
+
+ obj->loaded = true; /* doesn't matter if successfully or not */
+
+ if (err)
+ goto out;
return 0;
out:
+ /* unpin any maps that were auto-pinned during load */
+ for (i = 0; i < obj->nr_maps; i++)
+ if (obj->maps[i].pinned && !obj->maps[i].reused)
+ bpf_map__unpin(&obj->maps[i], NULL);
+
bpf_object__unload(obj);
- pr_warning("failed to load object '%s'\n", obj->path);
+ pr_warn("failed to load object '%s'\n", obj->path);
+ return err;
+}
+
+int bpf_object__load(struct bpf_object *obj)
+{
+ struct bpf_object_load_attr attr = {
+ .obj = obj,
+ };
+
+ return bpf_object__load_xattr(&attr);
+}
+
+static int make_parent_dir(const char *path)
+{
+ char *cp, errmsg[STRERR_BUFSIZE];
+ char *dname, *dir;
+ int err = 0;
+
+ dname = strdup(path);
+ if (dname == NULL)
+ return -ENOMEM;
+
+ dir = dirname(dname);
+ if (mkdir(dir, 0700) && errno != EEXIST)
+ err = -errno;
+
+ free(dname);
+ if (err) {
+ cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
+ pr_warn("failed to mkdir %s: %s\n", path, cp);
+ }
return err;
}
@@ -1662,14 +7410,14 @@
dir = dirname(dname);
if (statfs(dir, &st_fs)) {
- cp = str_error(errno, errmsg, sizeof(errmsg));
- pr_warning("failed to statfs %s: %s\n", dir, cp);
+ cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+ pr_warn("failed to statfs %s: %s\n", dir, cp);
err = -errno;
}
free(dname);
if (!err && st_fs.f_type != BPF_FS_MAGIC) {
- pr_warning("specified path %s is not on BPF FS\n", path);
+ pr_warn("specified path %s is not on BPF FS\n", path);
err = -EINVAL;
}
@@ -1682,47 +7430,131 @@
char *cp, errmsg[STRERR_BUFSIZE];
int err;
+ err = make_parent_dir(path);
+ if (err)
+ return err;
+
err = check_path(path);
if (err)
return err;
if (prog == NULL) {
- pr_warning("invalid program pointer\n");
+ pr_warn("invalid program pointer\n");
return -EINVAL;
}
if (instance < 0 || instance >= prog->instances.nr) {
- pr_warning("invalid prog instance %d of prog %s (max %d)\n",
- instance, prog->section_name, prog->instances.nr);
+ pr_warn("invalid prog instance %d of prog %s (max %d)\n",
+ instance, prog->name, prog->instances.nr);
return -EINVAL;
}
if (bpf_obj_pin(prog->instances.fds[instance], path)) {
- cp = str_error(errno, errmsg, sizeof(errmsg));
- pr_warning("failed to pin program: %s\n", cp);
- return -errno;
+ err = -errno;
+ cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+ pr_warn("failed to pin program: %s\n", cp);
+ return err;
}
pr_debug("pinned program '%s'\n", path);
return 0;
}
-static int make_dir(const char *path)
+int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
+ int instance)
{
- char *cp, errmsg[STRERR_BUFSIZE];
- int err = 0;
+ int err;
- if (mkdir(path, 0700) && errno != EEXIST)
- err = -errno;
+ err = check_path(path);
+ if (err)
+ return err;
- if (err) {
- cp = str_error(-err, errmsg, sizeof(errmsg));
- pr_warning("failed to mkdir %s: %s\n", path, cp);
+ if (prog == NULL) {
+ pr_warn("invalid program pointer\n");
+ return -EINVAL;
}
- return err;
+
+ if (instance < 0 || instance >= prog->instances.nr) {
+ pr_warn("invalid prog instance %d of prog %s (max %d)\n",
+ instance, prog->name, prog->instances.nr);
+ return -EINVAL;
+ }
+
+ err = unlink(path);
+ if (err != 0)
+ return -errno;
+ pr_debug("unpinned program '%s'\n", path);
+
+ return 0;
}
int bpf_program__pin(struct bpf_program *prog, const char *path)
+{
+ int i, err;
+
+ err = make_parent_dir(path);
+ if (err)
+ return err;
+
+ err = check_path(path);
+ if (err)
+ return err;
+
+ if (prog == NULL) {
+ pr_warn("invalid program pointer\n");
+ return -EINVAL;
+ }
+
+ if (prog->instances.nr <= 0) {
+ pr_warn("no instances of prog %s to pin\n", prog->name);
+ return -EINVAL;
+ }
+
+ if (prog->instances.nr == 1) {
+ /* don't create subdirs when pinning single instance */
+ return bpf_program__pin_instance(prog, path, 0);
+ }
+
+ for (i = 0; i < prog->instances.nr; i++) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin;
+ }
+
+ err = bpf_program__pin_instance(prog, buf, i);
+ if (err)
+ goto err_unpin;
+ }
+
+ return 0;
+
+err_unpin:
+ for (i = i - 1; i >= 0; i--) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_program__unpin_instance(prog, buf, i);
+ }
+
+ rmdir(path);
+
+ return err;
+}
+
+int bpf_program__unpin(struct bpf_program *prog, const char *path)
{
int i, err;
@@ -1731,19 +7563,19 @@
return err;
if (prog == NULL) {
- pr_warning("invalid program pointer\n");
+ pr_warn("invalid program pointer\n");
return -EINVAL;
}
if (prog->instances.nr <= 0) {
- pr_warning("no instances of prog %s to pin\n",
- prog->section_name);
+ pr_warn("no instances of prog %s to pin\n", prog->name);
return -EINVAL;
}
- err = make_dir(path);
- if (err)
- return err;
+ if (prog->instances.nr == 1) {
+ /* don't create subdirs when pinning single instance */
+ return bpf_program__unpin_instance(prog, path, 0);
+ }
for (i = 0; i < prog->instances.nr; i++) {
char buf[PATH_MAX];
@@ -1755,10 +7587,14 @@
else if (len >= PATH_MAX)
return -ENAMETOOLONG;
- err = bpf_program__pin_instance(prog, buf, i);
+ err = bpf_program__unpin_instance(prog, buf, i);
if (err)
return err;
}
+
+ err = rmdir(path);
+ if (err)
+ return -errno;
return 0;
}
@@ -1768,28 +7604,135 @@
char *cp, errmsg[STRERR_BUFSIZE];
int err;
+ if (map == NULL) {
+ pr_warn("invalid map pointer\n");
+ return -EINVAL;
+ }
+
+ if (map->pin_path) {
+ if (path && strcmp(path, map->pin_path)) {
+ pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
+ bpf_map__name(map), map->pin_path, path);
+ return -EINVAL;
+ } else if (map->pinned) {
+ pr_debug("map '%s' already pinned at '%s'; not re-pinning\n",
+ bpf_map__name(map), map->pin_path);
+ return 0;
+ }
+ } else {
+ if (!path) {
+ pr_warn("missing a path to pin map '%s' at\n",
+ bpf_map__name(map));
+ return -EINVAL;
+ } else if (map->pinned) {
+ pr_warn("map '%s' already pinned\n", bpf_map__name(map));
+ return -EEXIST;
+ }
+
+ map->pin_path = strdup(path);
+ if (!map->pin_path) {
+ err = -errno;
+ goto out_err;
+ }
+ }
+
+ err = make_parent_dir(map->pin_path);
+ if (err)
+ return err;
+
+ err = check_path(map->pin_path);
+ if (err)
+ return err;
+
+ if (bpf_obj_pin(map->fd, map->pin_path)) {
+ err = -errno;
+ goto out_err;
+ }
+
+ map->pinned = true;
+ pr_debug("pinned map '%s'\n", map->pin_path);
+
+ return 0;
+
+out_err:
+ cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
+ pr_warn("failed to pin map: %s\n", cp);
+ return err;
+}
+
+int bpf_map__unpin(struct bpf_map *map, const char *path)
+{
+ int err;
+
+ if (map == NULL) {
+ pr_warn("invalid map pointer\n");
+ return -EINVAL;
+ }
+
+ if (map->pin_path) {
+ if (path && strcmp(path, map->pin_path)) {
+ pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
+ bpf_map__name(map), map->pin_path, path);
+ return -EINVAL;
+ }
+ path = map->pin_path;
+ } else if (!path) {
+ pr_warn("no path to unpin map '%s' from\n",
+ bpf_map__name(map));
+ return -EINVAL;
+ }
+
err = check_path(path);
if (err)
return err;
- if (map == NULL) {
- pr_warning("invalid map pointer\n");
- return -EINVAL;
- }
-
- if (bpf_obj_pin(map->fd, path)) {
- cp = str_error(errno, errmsg, sizeof(errmsg));
- pr_warning("failed to pin map: %s\n", cp);
+ err = unlink(path);
+ if (err != 0)
return -errno;
- }
- pr_debug("pinned map '%s'\n", path);
+ map->pinned = false;
+ pr_debug("unpinned map '%s' from '%s'\n", bpf_map__name(map), path);
+
return 0;
}
-int bpf_object__pin(struct bpf_object *obj, const char *path)
+int bpf_map__set_pin_path(struct bpf_map *map, const char *path)
{
- struct bpf_program *prog;
+ char *new = NULL;
+
+ if (path) {
+ new = strdup(path);
+ if (!new)
+ return -errno;
+ }
+
+ free(map->pin_path);
+ map->pin_path = new;
+ return 0;
+}
+
+const char *bpf_map__get_pin_path(const struct bpf_map *map)
+{
+ return map->pin_path;
+}
+
+bool bpf_map__is_pinned(const struct bpf_map *map)
+{
+ return map->pinned;
+}
+
+static void sanitize_pin_path(char *s)
+{
+ /* bpffs disallows periods in path names */
+ while (*s) {
+ if (*s == '.')
+ *s = '_';
+ s++;
+ }
+}
+
+int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
+{
struct bpf_map *map;
int err;
@@ -1797,42 +7740,78 @@
return -ENOENT;
if (!obj->loaded) {
- pr_warning("object not yet loaded; load it first\n");
+ pr_warn("object not yet loaded; load it first\n");
return -ENOENT;
}
- err = make_dir(path);
- if (err)
- return err;
-
- bpf_map__for_each(map, obj) {
+ bpf_object__for_each_map(map, obj) {
+ char *pin_path = NULL;
char buf[PATH_MAX];
- int len;
- len = snprintf(buf, PATH_MAX, "%s/%s", path,
- bpf_map__name(map));
- if (len < 0)
- return -EINVAL;
- else if (len >= PATH_MAX)
- return -ENAMETOOLONG;
+ if (path) {
+ int len;
- err = bpf_map__pin(map, buf);
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_maps;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_maps;
+ }
+ sanitize_pin_path(buf);
+ pin_path = buf;
+ } else if (!map->pin_path) {
+ continue;
+ }
+
+ err = bpf_map__pin(map, pin_path);
if (err)
- return err;
+ goto err_unpin_maps;
}
- bpf_object__for_each_program(prog, obj) {
+ return 0;
+
+err_unpin_maps:
+ while ((map = bpf_map__prev(map, obj))) {
+ if (!map->pin_path)
+ continue;
+
+ bpf_map__unpin(map, NULL);
+ }
+
+ return err;
+}
+
+int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
+{
+ struct bpf_map *map;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ bpf_object__for_each_map(map, obj) {
+ char *pin_path = NULL;
char buf[PATH_MAX];
- int len;
- len = snprintf(buf, PATH_MAX, "%s/%s", path,
- prog->section_name);
- if (len < 0)
- return -EINVAL;
- else if (len >= PATH_MAX)
- return -ENAMETOOLONG;
+ if (path) {
+ int len;
- err = bpf_program__pin(prog, buf);
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ bpf_map__name(map));
+ if (len < 0)
+ return -EINVAL;
+ else if (len >= PATH_MAX)
+ return -ENAMETOOLONG;
+ sanitize_pin_path(buf);
+ pin_path = buf;
+ } else if (!map->pin_path) {
+ continue;
+ }
+
+ err = bpf_map__unpin(map, pin_path);
if (err)
return err;
}
@@ -1840,11 +7819,141 @@
return 0;
}
+int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
+{
+ struct bpf_program *prog;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ if (!obj->loaded) {
+ pr_warn("object not yet loaded; load it first\n");
+ return -ENOENT;
+ }
+
+ bpf_object__for_each_program(prog, obj) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ prog->pin_name);
+ if (len < 0) {
+ err = -EINVAL;
+ goto err_unpin_programs;
+ } else if (len >= PATH_MAX) {
+ err = -ENAMETOOLONG;
+ goto err_unpin_programs;
+ }
+
+ err = bpf_program__pin(prog, buf);
+ if (err)
+ goto err_unpin_programs;
+ }
+
+ return 0;
+
+err_unpin_programs:
+ while ((prog = bpf_program__prev(prog, obj))) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ prog->pin_name);
+ if (len < 0)
+ continue;
+ else if (len >= PATH_MAX)
+ continue;
+
+ bpf_program__unpin(prog, buf);
+ }
+
+ return err;
+}
+
+int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
+{
+ struct bpf_program *prog;
+ int err;
+
+ if (!obj)
+ return -ENOENT;
+
+ bpf_object__for_each_program(prog, obj) {
+ char buf[PATH_MAX];
+ int len;
+
+ len = snprintf(buf, PATH_MAX, "%s/%s", path,
+ prog->pin_name);
+ if (len < 0)
+ return -EINVAL;
+ else if (len >= PATH_MAX)
+ return -ENAMETOOLONG;
+
+ err = bpf_program__unpin(prog, buf);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+int bpf_object__pin(struct bpf_object *obj, const char *path)
+{
+ int err;
+
+ err = bpf_object__pin_maps(obj, path);
+ if (err)
+ return err;
+
+ err = bpf_object__pin_programs(obj, path);
+ if (err) {
+ bpf_object__unpin_maps(obj, path);
+ return err;
+ }
+
+ return 0;
+}
+
+static void bpf_map__destroy(struct bpf_map *map)
+{
+ if (map->clear_priv)
+ map->clear_priv(map, map->priv);
+ map->priv = NULL;
+ map->clear_priv = NULL;
+
+ if (map->inner_map) {
+ bpf_map__destroy(map->inner_map);
+ zfree(&map->inner_map);
+ }
+
+ zfree(&map->init_slots);
+ map->init_slots_sz = 0;
+
+ if (map->mmaped) {
+ munmap(map->mmaped, bpf_map_mmap_sz(map));
+ map->mmaped = NULL;
+ }
+
+ if (map->st_ops) {
+ zfree(&map->st_ops->data);
+ zfree(&map->st_ops->progs);
+ zfree(&map->st_ops->kern_func_off);
+ zfree(&map->st_ops);
+ }
+
+ zfree(&map->name);
+ zfree(&map->pin_path);
+
+ if (map->fd >= 0)
+ zclose(map->fd);
+}
+
void bpf_object__close(struct bpf_object *obj)
{
size_t i;
- if (!obj)
+ if (IS_ERR_OR_NULL(obj))
return;
if (obj->clear_priv)
@@ -1853,15 +7962,15 @@
bpf_object__elf_finish(obj);
bpf_object__unload(obj);
btf__free(obj->btf);
+ btf_ext__free(obj->btf_ext);
- for (i = 0; i < obj->nr_maps; i++) {
- zfree(&obj->maps[i].name);
- if (obj->maps[i].clear_priv)
- obj->maps[i].clear_priv(&obj->maps[i],
- obj->maps[i].priv);
- obj->maps[i].priv = NULL;
- obj->maps[i].clear_priv = NULL;
- }
+ for (i = 0; i < obj->nr_maps; i++)
+ bpf_map__destroy(&obj->maps[i]);
+
+ zfree(&obj->kconfig);
+ zfree(&obj->externs);
+ obj->nr_extern = 0;
+
zfree(&obj->maps);
obj->nr_maps = 0;
@@ -1894,14 +8003,19 @@
return next;
}
-const char *bpf_object__name(struct bpf_object *obj)
+const char *bpf_object__name(const struct bpf_object *obj)
{
- return obj ? obj->path : ERR_PTR(-EINVAL);
+ return obj ? obj->name : ERR_PTR(-EINVAL);
}
-unsigned int bpf_object__kversion(struct bpf_object *obj)
+unsigned int bpf_object__kversion(const struct bpf_object *obj)
{
return obj ? obj->kern_version : 0;
+}
+
+struct btf *bpf_object__btf(const struct bpf_object *obj)
+{
+ return obj ? obj->btf : NULL;
}
int bpf_object__btf_fd(const struct bpf_object *obj)
@@ -1920,41 +8034,57 @@
return 0;
}
-void *bpf_object__priv(struct bpf_object *obj)
+void *bpf_object__priv(const struct bpf_object *obj)
{
return obj ? obj->priv : ERR_PTR(-EINVAL);
}
static struct bpf_program *
-__bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
+__bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj,
+ bool forward)
{
- size_t idx;
+ size_t nr_programs = obj->nr_programs;
+ ssize_t idx;
- if (!obj->programs)
+ if (!nr_programs)
return NULL;
- /* First handler */
- if (prev == NULL)
- return &obj->programs[0];
- if (prev->obj != obj) {
- pr_warning("error: program handler doesn't match object\n");
+ if (!p)
+ /* Iter from the beginning */
+ return forward ? &obj->programs[0] :
+ &obj->programs[nr_programs - 1];
+
+ if (p->obj != obj) {
+ pr_warn("error: program handler doesn't match object\n");
return NULL;
}
- idx = (prev - obj->programs) + 1;
- if (idx >= obj->nr_programs)
+ idx = (p - obj->programs) + (forward ? 1 : -1);
+ if (idx >= obj->nr_programs || idx < 0)
return NULL;
return &obj->programs[idx];
}
struct bpf_program *
-bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
+bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj)
{
struct bpf_program *prog = prev;
do {
- prog = __bpf_program__next(prog, obj);
- } while (prog && bpf_program__is_function_storage(prog, obj));
+ prog = __bpf_program__iter(prog, obj, true);
+ } while (prog && prog_is_subprog(obj, prog));
+
+ return prog;
+}
+
+struct bpf_program *
+bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj)
+{
+ struct bpf_program *prog = next;
+
+ do {
+ prog = __bpf_program__iter(prog, obj, false);
+ } while (prog && prog_is_subprog(obj, prog));
return prog;
}
@@ -1970,7 +8100,7 @@
return 0;
}
-void *bpf_program__priv(struct bpf_program *prog)
+void *bpf_program__priv(const struct bpf_program *prog)
{
return prog ? prog->priv : ERR_PTR(-EINVAL);
}
@@ -1980,15 +8110,25 @@
prog->prog_ifindex = ifindex;
}
-const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
+const char *bpf_program__name(const struct bpf_program *prog)
+{
+ return prog->name;
+}
+
+const char *bpf_program__section_name(const struct bpf_program *prog)
+{
+ return prog->sec_name;
+}
+
+const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy)
{
const char *title;
- title = prog->section_name;
+ title = prog->sec_name;
if (needs_copy) {
title = strdup(title);
if (!title) {
- pr_warning("failed to strdup program title\n");
+ pr_warn("failed to strdup program title\n");
return ERR_PTR(-ENOMEM);
}
}
@@ -1996,9 +8136,28 @@
return title;
}
-int bpf_program__fd(struct bpf_program *prog)
+bool bpf_program__autoload(const struct bpf_program *prog)
+{
+ return prog->load;
+}
+
+int bpf_program__set_autoload(struct bpf_program *prog, bool autoload)
+{
+ if (prog->obj->loaded)
+ return -EINVAL;
+
+ prog->load = autoload;
+ return 0;
+}
+
+int bpf_program__fd(const struct bpf_program *prog)
{
return bpf_program__nth_fd(prog, 0);
+}
+
+size_t bpf_program__size(const struct bpf_program *prog)
+{
+ return prog->insns_cnt * BPF_INSN_SZ;
}
int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
@@ -2010,13 +8169,13 @@
return -EINVAL;
if (prog->instances.nr > 0 || prog->instances.fds) {
- pr_warning("Can't set pre-processor after loading\n");
+ pr_warn("Can't set pre-processor after loading\n");
return -EINVAL;
}
instances_fds = malloc(sizeof(int) * nr_instances);
if (!instances_fds) {
- pr_warning("alloc memory failed for fds\n");
+ pr_warn("alloc memory failed for fds\n");
return -ENOMEM;
}
@@ -2029,7 +8188,7 @@
return 0;
}
-int bpf_program__nth_fd(struct bpf_program *prog, int n)
+int bpf_program__nth_fd(const struct bpf_program *prog, int n)
{
int fd;
@@ -2037,19 +8196,24 @@
return -EINVAL;
if (n >= prog->instances.nr || n < 0) {
- pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
- n, prog->section_name, prog->instances.nr);
+ pr_warn("Can't get the %dth fd from program %s: only %d instances\n",
+ n, prog->name, prog->instances.nr);
return -EINVAL;
}
fd = prog->instances.fds[n];
if (fd < 0) {
- pr_warning("%dth instance of program '%s' is invalid\n",
- n, prog->section_name);
+ pr_warn("%dth instance of program '%s' is invalid\n",
+ n, prog->name);
return -ENOENT;
}
return fd;
+}
+
+enum bpf_prog_type bpf_program__get_type(struct bpf_program *prog)
+{
+ return prog->type;
}
void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
@@ -2057,27 +8221,28 @@
prog->type = type;
}
-static bool bpf_program__is_type(struct bpf_program *prog,
+static bool bpf_program__is_type(const struct bpf_program *prog,
enum bpf_prog_type type)
{
return prog ? (prog->type == type) : false;
}
-#define BPF_PROG_TYPE_FNS(NAME, TYPE) \
-int bpf_program__set_##NAME(struct bpf_program *prog) \
-{ \
- if (!prog) \
- return -EINVAL; \
- bpf_program__set_type(prog, TYPE); \
- return 0; \
-} \
- \
-bool bpf_program__is_##NAME(struct bpf_program *prog) \
-{ \
- return bpf_program__is_type(prog, TYPE); \
-} \
+#define BPF_PROG_TYPE_FNS(NAME, TYPE) \
+int bpf_program__set_##NAME(struct bpf_program *prog) \
+{ \
+ if (!prog) \
+ return -EINVAL; \
+ bpf_program__set_type(prog, TYPE); \
+ return 0; \
+} \
+ \
+bool bpf_program__is_##NAME(const struct bpf_program *prog) \
+{ \
+ return bpf_program__is_type(prog, TYPE); \
+} \
BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER);
+BPF_PROG_TYPE_FNS(lsm, BPF_PROG_TYPE_LSM);
BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE);
BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS);
BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT);
@@ -2085,6 +8250,16 @@
BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT);
BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
+BPF_PROG_TYPE_FNS(tracing, BPF_PROG_TYPE_TRACING);
+BPF_PROG_TYPE_FNS(struct_ops, BPF_PROG_TYPE_STRUCT_OPS);
+BPF_PROG_TYPE_FNS(extension, BPF_PROG_TYPE_EXT);
+BPF_PROG_TYPE_FNS(sk_lookup, BPF_PROG_TYPE_SK_LOOKUP);
+
+enum bpf_attach_type
+bpf_program__get_expected_attach_type(struct bpf_program *prog)
+{
+ return prog->expected_attach_type;
+}
void bpf_program__set_expected_attach_type(struct bpf_program *prog,
enum bpf_attach_type type)
@@ -2092,98 +8267,636 @@
prog->expected_attach_type = type;
}
-#define BPF_PROG_SEC_FULL(string, ptype, atype) \
- { string, sizeof(string) - 1, ptype, atype }
+#define BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype_optional, \
+ attachable, attach_btf) \
+ { \
+ .sec = string, \
+ .len = sizeof(string) - 1, \
+ .prog_type = ptype, \
+ .expected_attach_type = eatype, \
+ .is_exp_attach_type_optional = eatype_optional, \
+ .is_attachable = attachable, \
+ .is_attach_btf = attach_btf, \
+ }
-#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_FULL(string, ptype, 0)
+/* Programs that can NOT be attached. */
+#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0, 0)
-#define BPF_S_PROG_SEC(string, ptype) \
- BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK, ptype)
+/* Programs that can be attached. */
+#define BPF_APROG_SEC(string, ptype, atype) \
+ BPF_PROG_SEC_IMPL(string, ptype, atype, true, 1, 0)
-#define BPF_SA_PROG_SEC(string, ptype) \
- BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, ptype)
+/* Programs that must specify expected attach type at load time. */
+#define BPF_EAPROG_SEC(string, ptype, eatype) \
+ BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 1, 0)
-static const struct {
- const char *sec;
- size_t len;
- enum bpf_prog_type prog_type;
- enum bpf_attach_type expected_attach_type;
-} section_names[] = {
- BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
- BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE),
- BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE),
- BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS),
- BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT),
- BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT),
- BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT),
- BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
- BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
- BPF_PROG_SEC("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB),
- BPF_PROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK),
- BPF_PROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE),
- BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
- BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT),
- BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT),
- BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL),
- BPF_PROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS),
- BPF_PROG_SEC("sk_skb", BPF_PROG_TYPE_SK_SKB),
- BPF_PROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG),
- BPF_PROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2),
- BPF_SA_PROG_SEC("cgroup/bind4", BPF_CGROUP_INET4_BIND),
- BPF_SA_PROG_SEC("cgroup/bind6", BPF_CGROUP_INET6_BIND),
- BPF_SA_PROG_SEC("cgroup/connect4", BPF_CGROUP_INET4_CONNECT),
- BPF_SA_PROG_SEC("cgroup/connect6", BPF_CGROUP_INET6_CONNECT),
- BPF_SA_PROG_SEC("cgroup/sendmsg4", BPF_CGROUP_UDP4_SENDMSG),
- BPF_SA_PROG_SEC("cgroup/sendmsg6", BPF_CGROUP_UDP6_SENDMSG),
- BPF_S_PROG_SEC("cgroup/post_bind4", BPF_CGROUP_INET4_POST_BIND),
- BPF_S_PROG_SEC("cgroup/post_bind6", BPF_CGROUP_INET6_POST_BIND),
+/* Programs that use BTF to identify attach point */
+#define BPF_PROG_BTF(string, ptype, eatype) \
+ BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 0, 1)
+
+/* Programs that can be attached but attach type can't be identified by section
+ * name. Kept for backward compatibility.
+ */
+#define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
+
+#define SEC_DEF(sec_pfx, ptype, ...) { \
+ .sec = sec_pfx, \
+ .len = sizeof(sec_pfx) - 1, \
+ .prog_type = BPF_PROG_TYPE_##ptype, \
+ __VA_ARGS__ \
+}
+
+static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
+ struct bpf_program *prog);
+
+static const struct bpf_sec_def section_defs[] = {
+ BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
+ BPF_PROG_SEC("sk_reuseport", BPF_PROG_TYPE_SK_REUSEPORT),
+ SEC_DEF("kprobe/", KPROBE,
+ .attach_fn = attach_kprobe),
+ BPF_PROG_SEC("uprobe/", BPF_PROG_TYPE_KPROBE),
+ SEC_DEF("kretprobe/", KPROBE,
+ .attach_fn = attach_kprobe),
+ BPF_PROG_SEC("uretprobe/", BPF_PROG_TYPE_KPROBE),
+ BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS),
+ BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT),
+ SEC_DEF("tracepoint/", TRACEPOINT,
+ .attach_fn = attach_tp),
+ SEC_DEF("tp/", TRACEPOINT,
+ .attach_fn = attach_tp),
+ SEC_DEF("raw_tracepoint/", RAW_TRACEPOINT,
+ .attach_fn = attach_raw_tp),
+ SEC_DEF("raw_tp/", RAW_TRACEPOINT,
+ .attach_fn = attach_raw_tp),
+ SEC_DEF("tp_btf/", TRACING,
+ .expected_attach_type = BPF_TRACE_RAW_TP,
+ .is_attach_btf = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("fentry/", TRACING,
+ .expected_attach_type = BPF_TRACE_FENTRY,
+ .is_attach_btf = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("fmod_ret/", TRACING,
+ .expected_attach_type = BPF_MODIFY_RETURN,
+ .is_attach_btf = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("fexit/", TRACING,
+ .expected_attach_type = BPF_TRACE_FEXIT,
+ .is_attach_btf = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("fentry.s/", TRACING,
+ .expected_attach_type = BPF_TRACE_FENTRY,
+ .is_attach_btf = true,
+ .is_sleepable = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("fmod_ret.s/", TRACING,
+ .expected_attach_type = BPF_MODIFY_RETURN,
+ .is_attach_btf = true,
+ .is_sleepable = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("fexit.s/", TRACING,
+ .expected_attach_type = BPF_TRACE_FEXIT,
+ .is_attach_btf = true,
+ .is_sleepable = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("freplace/", EXT,
+ .is_attach_btf = true,
+ .attach_fn = attach_trace),
+ SEC_DEF("lsm/", LSM,
+ .is_attach_btf = true,
+ .expected_attach_type = BPF_LSM_MAC,
+ .attach_fn = attach_lsm),
+ SEC_DEF("lsm.s/", LSM,
+ .is_attach_btf = true,
+ .is_sleepable = true,
+ .expected_attach_type = BPF_LSM_MAC,
+ .attach_fn = attach_lsm),
+ SEC_DEF("iter/", TRACING,
+ .expected_attach_type = BPF_TRACE_ITER,
+ .is_attach_btf = true,
+ .attach_fn = attach_iter),
+ BPF_EAPROG_SEC("xdp_devmap/", BPF_PROG_TYPE_XDP,
+ BPF_XDP_DEVMAP),
+ BPF_EAPROG_SEC("xdp_cpumap/", BPF_PROG_TYPE_XDP,
+ BPF_XDP_CPUMAP),
+ BPF_APROG_SEC("xdp", BPF_PROG_TYPE_XDP,
+ BPF_XDP),
+ BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
+ BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
+ BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT),
+ BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT),
+ BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL),
+ BPF_APROG_SEC("cgroup_skb/ingress", BPF_PROG_TYPE_CGROUP_SKB,
+ BPF_CGROUP_INET_INGRESS),
+ BPF_APROG_SEC("cgroup_skb/egress", BPF_PROG_TYPE_CGROUP_SKB,
+ BPF_CGROUP_INET_EGRESS),
+ BPF_APROG_COMPAT("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB),
+ BPF_EAPROG_SEC("cgroup/sock_create", BPF_PROG_TYPE_CGROUP_SOCK,
+ BPF_CGROUP_INET_SOCK_CREATE),
+ BPF_EAPROG_SEC("cgroup/sock_release", BPF_PROG_TYPE_CGROUP_SOCK,
+ BPF_CGROUP_INET_SOCK_RELEASE),
+ BPF_APROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK,
+ BPF_CGROUP_INET_SOCK_CREATE),
+ BPF_EAPROG_SEC("cgroup/post_bind4", BPF_PROG_TYPE_CGROUP_SOCK,
+ BPF_CGROUP_INET4_POST_BIND),
+ BPF_EAPROG_SEC("cgroup/post_bind6", BPF_PROG_TYPE_CGROUP_SOCK,
+ BPF_CGROUP_INET6_POST_BIND),
+ BPF_APROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE,
+ BPF_CGROUP_DEVICE),
+ BPF_APROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS,
+ BPF_CGROUP_SOCK_OPS),
+ BPF_APROG_SEC("sk_skb/stream_parser", BPF_PROG_TYPE_SK_SKB,
+ BPF_SK_SKB_STREAM_PARSER),
+ BPF_APROG_SEC("sk_skb/stream_verdict", BPF_PROG_TYPE_SK_SKB,
+ BPF_SK_SKB_STREAM_VERDICT),
+ BPF_APROG_COMPAT("sk_skb", BPF_PROG_TYPE_SK_SKB),
+ BPF_APROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG,
+ BPF_SK_MSG_VERDICT),
+ BPF_APROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2,
+ BPF_LIRC_MODE2),
+ BPF_APROG_SEC("flow_dissector", BPF_PROG_TYPE_FLOW_DISSECTOR,
+ BPF_FLOW_DISSECTOR),
+ BPF_EAPROG_SEC("cgroup/bind4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET4_BIND),
+ BPF_EAPROG_SEC("cgroup/bind6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET6_BIND),
+ BPF_EAPROG_SEC("cgroup/connect4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET4_CONNECT),
+ BPF_EAPROG_SEC("cgroup/connect6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET6_CONNECT),
+ BPF_EAPROG_SEC("cgroup/sendmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_UDP4_SENDMSG),
+ BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_UDP6_SENDMSG),
+ BPF_EAPROG_SEC("cgroup/recvmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_UDP4_RECVMSG),
+ BPF_EAPROG_SEC("cgroup/recvmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_UDP6_RECVMSG),
+ BPF_EAPROG_SEC("cgroup/getpeername4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET4_GETPEERNAME),
+ BPF_EAPROG_SEC("cgroup/getpeername6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET6_GETPEERNAME),
+ BPF_EAPROG_SEC("cgroup/getsockname4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET4_GETSOCKNAME),
+ BPF_EAPROG_SEC("cgroup/getsockname6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+ BPF_CGROUP_INET6_GETSOCKNAME),
+ BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL,
+ BPF_CGROUP_SYSCTL),
+ BPF_EAPROG_SEC("cgroup/getsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
+ BPF_CGROUP_GETSOCKOPT),
+ BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
+ BPF_CGROUP_SETSOCKOPT),
+ BPF_PROG_SEC("struct_ops", BPF_PROG_TYPE_STRUCT_OPS),
+ BPF_EAPROG_SEC("sk_lookup/", BPF_PROG_TYPE_SK_LOOKUP,
+ BPF_SK_LOOKUP),
};
+#undef BPF_PROG_SEC_IMPL
#undef BPF_PROG_SEC
-#undef BPF_PROG_SEC_FULL
-#undef BPF_S_PROG_SEC
-#undef BPF_SA_PROG_SEC
+#undef BPF_APROG_SEC
+#undef BPF_EAPROG_SEC
+#undef BPF_APROG_COMPAT
+#undef SEC_DEF
+
+#define MAX_TYPE_NAME_SIZE 32
+
+static const struct bpf_sec_def *find_sec_def(const char *sec_name)
+{
+ int i, n = ARRAY_SIZE(section_defs);
+
+ for (i = 0; i < n; i++) {
+ if (strncmp(sec_name,
+ section_defs[i].sec, section_defs[i].len))
+ continue;
+ return §ion_defs[i];
+ }
+ return NULL;
+}
+
+static char *libbpf_get_type_names(bool attach_type)
+{
+ int i, len = ARRAY_SIZE(section_defs) * MAX_TYPE_NAME_SIZE;
+ char *buf;
+
+ buf = malloc(len);
+ if (!buf)
+ return NULL;
+
+ buf[0] = '\0';
+ /* Forge string buf with all available names */
+ for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
+ if (attach_type && !section_defs[i].is_attachable)
+ continue;
+
+ if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) {
+ free(buf);
+ return NULL;
+ }
+ strcat(buf, " ");
+ strcat(buf, section_defs[i].sec);
+ }
+
+ return buf;
+}
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
enum bpf_attach_type *expected_attach_type)
{
+ const struct bpf_sec_def *sec_def;
+ char *type_names;
+
+ if (!name)
+ return -EINVAL;
+
+ sec_def = find_sec_def(name);
+ if (sec_def) {
+ *prog_type = sec_def->prog_type;
+ *expected_attach_type = sec_def->expected_attach_type;
+ return 0;
+ }
+
+ pr_debug("failed to guess program type from ELF section '%s'\n", name);
+ type_names = libbpf_get_type_names(false);
+ if (type_names != NULL) {
+ pr_debug("supported section(type) names are:%s\n", type_names);
+ free(type_names);
+ }
+
+ return -ESRCH;
+}
+
+static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
+ size_t offset)
+{
+ struct bpf_map *map;
+ size_t i;
+
+ for (i = 0; i < obj->nr_maps; i++) {
+ map = &obj->maps[i];
+ if (!bpf_map__is_struct_ops(map))
+ continue;
+ if (map->sec_offset <= offset &&
+ offset - map->sec_offset < map->def.value_size)
+ return map;
+ }
+
+ return NULL;
+}
+
+/* Collect the reloc from ELF and populate the st_ops->progs[] */
+static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
+ GElf_Shdr *shdr, Elf_Data *data)
+{
+ const struct btf_member *member;
+ struct bpf_struct_ops *st_ops;
+ struct bpf_program *prog;
+ unsigned int shdr_idx;
+ const struct btf *btf;
+ struct bpf_map *map;
+ Elf_Data *symbols;
+ unsigned int moff, insn_idx;
+ const char *name;
+ __u32 member_idx;
+ GElf_Sym sym;
+ GElf_Rel rel;
+ int i, nrels;
+
+ symbols = obj->efile.symbols;
+ btf = obj->btf;
+ nrels = shdr->sh_size / shdr->sh_entsize;
+ for (i = 0; i < nrels; i++) {
+ if (!gelf_getrel(data, i, &rel)) {
+ pr_warn("struct_ops reloc: failed to get %d reloc\n", i);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+ pr_warn("struct_ops reloc: symbol %zx not found\n",
+ (size_t)GELF_R_SYM(rel.r_info));
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ name = elf_sym_str(obj, sym.st_name) ?: "<?>";
+ map = find_struct_ops_map_by_offset(obj, rel.r_offset);
+ if (!map) {
+ pr_warn("struct_ops reloc: cannot find map at rel.r_offset %zu\n",
+ (size_t)rel.r_offset);
+ return -EINVAL;
+ }
+
+ moff = rel.r_offset - map->sec_offset;
+ shdr_idx = sym.st_shndx;
+ st_ops = map->st_ops;
+ pr_debug("struct_ops reloc %s: for %lld value %lld shdr_idx %u rel.r_offset %zu map->sec_offset %zu name %d (\'%s\')\n",
+ map->name,
+ (long long)(rel.r_info >> 32),
+ (long long)sym.st_value,
+ shdr_idx, (size_t)rel.r_offset,
+ map->sec_offset, sym.st_name, name);
+
+ if (shdr_idx >= SHN_LORESERVE) {
+ pr_warn("struct_ops reloc %s: rel.r_offset %zu shdr_idx %u unsupported non-static function\n",
+ map->name, (size_t)rel.r_offset, shdr_idx);
+ return -LIBBPF_ERRNO__RELOC;
+ }
+ if (sym.st_value % BPF_INSN_SZ) {
+ pr_warn("struct_ops reloc %s: invalid target program offset %llu\n",
+ map->name, (unsigned long long)sym.st_value);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+ insn_idx = sym.st_value / BPF_INSN_SZ;
+
+ member = find_member_by_offset(st_ops->type, moff * 8);
+ if (!member) {
+ pr_warn("struct_ops reloc %s: cannot find member at moff %u\n",
+ map->name, moff);
+ return -EINVAL;
+ }
+ member_idx = member - btf_members(st_ops->type);
+ name = btf__name_by_offset(btf, member->name_off);
+
+ if (!resolve_func_ptr(btf, member->type, NULL)) {
+ pr_warn("struct_ops reloc %s: cannot relocate non func ptr %s\n",
+ map->name, name);
+ return -EINVAL;
+ }
+
+ prog = find_prog_by_sec_insn(obj, shdr_idx, insn_idx);
+ if (!prog) {
+ pr_warn("struct_ops reloc %s: cannot find prog at shdr_idx %u to relocate func ptr %s\n",
+ map->name, shdr_idx, name);
+ return -EINVAL;
+ }
+
+ if (prog->type == BPF_PROG_TYPE_UNSPEC) {
+ const struct bpf_sec_def *sec_def;
+
+ sec_def = find_sec_def(prog->sec_name);
+ if (sec_def &&
+ sec_def->prog_type != BPF_PROG_TYPE_STRUCT_OPS) {
+ /* for pr_warn */
+ prog->type = sec_def->prog_type;
+ goto invalid_prog;
+ }
+
+ prog->type = BPF_PROG_TYPE_STRUCT_OPS;
+ prog->attach_btf_id = st_ops->type_id;
+ prog->expected_attach_type = member_idx;
+ } else if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
+ prog->attach_btf_id != st_ops->type_id ||
+ prog->expected_attach_type != member_idx) {
+ goto invalid_prog;
+ }
+ st_ops->progs[member_idx] = prog;
+ }
+
+ return 0;
+
+invalid_prog:
+ pr_warn("struct_ops reloc %s: cannot use prog %s in sec %s with type %u attach_btf_id %u expected_attach_type %u for func ptr %s\n",
+ map->name, prog->name, prog->sec_name, prog->type,
+ prog->attach_btf_id, prog->expected_attach_type, name);
+ return -EINVAL;
+}
+
+#define BTF_TRACE_PREFIX "btf_trace_"
+#define BTF_LSM_PREFIX "bpf_lsm_"
+#define BTF_ITER_PREFIX "bpf_iter_"
+#define BTF_MAX_NAME_SIZE 128
+
+static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
+ const char *name, __u32 kind)
+{
+ char btf_type_name[BTF_MAX_NAME_SIZE];
+ int ret;
+
+ ret = snprintf(btf_type_name, sizeof(btf_type_name),
+ "%s%s", prefix, name);
+ /* snprintf returns the number of characters written excluding the
+ * the terminating null. So, if >= BTF_MAX_NAME_SIZE are written, it
+ * indicates truncation.
+ */
+ if (ret < 0 || ret >= sizeof(btf_type_name))
+ return -ENAMETOOLONG;
+ return btf__find_by_name_kind(btf, btf_type_name, kind);
+}
+
+static inline int __find_vmlinux_btf_id(struct btf *btf, const char *name,
+ enum bpf_attach_type attach_type)
+{
+ int err;
+
+ if (attach_type == BPF_TRACE_RAW_TP)
+ err = find_btf_by_prefix_kind(btf, BTF_TRACE_PREFIX, name,
+ BTF_KIND_TYPEDEF);
+ else if (attach_type == BPF_LSM_MAC)
+ err = find_btf_by_prefix_kind(btf, BTF_LSM_PREFIX, name,
+ BTF_KIND_FUNC);
+ else if (attach_type == BPF_TRACE_ITER)
+ err = find_btf_by_prefix_kind(btf, BTF_ITER_PREFIX, name,
+ BTF_KIND_FUNC);
+ else
+ err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
+
+ if (err <= 0)
+ pr_warn("%s is not found in vmlinux BTF\n", name);
+
+ return err;
+}
+
+int libbpf_find_vmlinux_btf_id(const char *name,
+ enum bpf_attach_type attach_type)
+{
+ struct btf *btf;
+ int err;
+
+ btf = libbpf_find_kernel_btf();
+ if (IS_ERR(btf)) {
+ pr_warn("vmlinux BTF is not found\n");
+ return -EINVAL;
+ }
+
+ err = __find_vmlinux_btf_id(btf, name, attach_type);
+ btf__free(btf);
+ return err;
+}
+
+static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
+{
+ struct bpf_prog_info_linear *info_linear;
+ struct bpf_prog_info *info;
+ struct btf *btf = NULL;
+ int err = -EINVAL;
+
+ info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
+ if (IS_ERR_OR_NULL(info_linear)) {
+ pr_warn("failed get_prog_info_linear for FD %d\n",
+ attach_prog_fd);
+ return -EINVAL;
+ }
+ info = &info_linear->info;
+ if (!info->btf_id) {
+ pr_warn("The target program doesn't have BTF\n");
+ goto out;
+ }
+ if (btf__get_from_id(info->btf_id, &btf)) {
+ pr_warn("Failed to get BTF of the program\n");
+ goto out;
+ }
+ err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
+ btf__free(btf);
+ if (err <= 0) {
+ pr_warn("%s is not found in prog's BTF\n", name);
+ goto out;
+ }
+out:
+ free(info_linear);
+ return err;
+}
+
+static int libbpf_find_attach_btf_id(struct bpf_program *prog)
+{
+ enum bpf_attach_type attach_type = prog->expected_attach_type;
+ __u32 attach_prog_fd = prog->attach_prog_fd;
+ const char *name = prog->sec_name;
+ int i, err;
+
+ if (!name)
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
+ if (!section_defs[i].is_attach_btf)
+ continue;
+ if (strncmp(name, section_defs[i].sec, section_defs[i].len))
+ continue;
+ if (attach_prog_fd)
+ err = libbpf_find_prog_btf_id(name + section_defs[i].len,
+ attach_prog_fd);
+ else
+ err = __find_vmlinux_btf_id(prog->obj->btf_vmlinux,
+ name + section_defs[i].len,
+ attach_type);
+ return err;
+ }
+ pr_warn("failed to identify btf_id based on ELF section name '%s'\n", name);
+ return -ESRCH;
+}
+
+int libbpf_attach_type_by_name(const char *name,
+ enum bpf_attach_type *attach_type)
+{
+ char *type_names;
int i;
if (!name)
return -EINVAL;
- for (i = 0; i < ARRAY_SIZE(section_names); i++) {
- if (strncmp(name, section_names[i].sec, section_names[i].len))
+ for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
+ if (strncmp(name, section_defs[i].sec, section_defs[i].len))
continue;
- *prog_type = section_names[i].prog_type;
- *expected_attach_type = section_names[i].expected_attach_type;
+ if (!section_defs[i].is_attachable)
+ return -EINVAL;
+ *attach_type = section_defs[i].expected_attach_type;
return 0;
}
+ pr_debug("failed to guess attach type based on ELF section name '%s'\n", name);
+ type_names = libbpf_get_type_names(true);
+ if (type_names != NULL) {
+ pr_debug("attachable section(type) names are:%s\n", type_names);
+ free(type_names);
+ }
+
return -EINVAL;
}
-static int
-bpf_program__identify_section(struct bpf_program *prog,
- enum bpf_prog_type *prog_type,
- enum bpf_attach_type *expected_attach_type)
-{
- return libbpf_prog_type_by_name(prog->section_name, prog_type,
- expected_attach_type);
-}
-
-int bpf_map__fd(struct bpf_map *map)
+int bpf_map__fd(const struct bpf_map *map)
{
return map ? map->fd : -EINVAL;
}
-const struct bpf_map_def *bpf_map__def(struct bpf_map *map)
+const struct bpf_map_def *bpf_map__def(const struct bpf_map *map)
{
return map ? &map->def : ERR_PTR(-EINVAL);
}
-const char *bpf_map__name(struct bpf_map *map)
+const char *bpf_map__name(const struct bpf_map *map)
{
return map ? map->name : NULL;
+}
+
+enum bpf_map_type bpf_map__type(const struct bpf_map *map)
+{
+ return map->def.type;
+}
+
+int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->def.type = type;
+ return 0;
+}
+
+__u32 bpf_map__map_flags(const struct bpf_map *map)
+{
+ return map->def.map_flags;
+}
+
+int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->def.map_flags = flags;
+ return 0;
+}
+
+__u32 bpf_map__numa_node(const struct bpf_map *map)
+{
+ return map->numa_node;
+}
+
+int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->numa_node = numa_node;
+ return 0;
+}
+
+__u32 bpf_map__key_size(const struct bpf_map *map)
+{
+ return map->def.key_size;
+}
+
+int bpf_map__set_key_size(struct bpf_map *map, __u32 size)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->def.key_size = size;
+ return 0;
+}
+
+__u32 bpf_map__value_size(const struct bpf_map *map)
+{
+ return map->def.value_size;
+}
+
+int bpf_map__set_value_size(struct bpf_map *map, __u32 size)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->def.value_size = size;
+ return 0;
}
__u32 bpf_map__btf_key_type_id(const struct bpf_map *map)
@@ -2212,25 +8925,63 @@
return 0;
}
-void *bpf_map__priv(struct bpf_map *map)
+void *bpf_map__priv(const struct bpf_map *map)
{
return map ? map->priv : ERR_PTR(-EINVAL);
}
-bool bpf_map__is_offload_neutral(struct bpf_map *map)
+int bpf_map__set_initial_value(struct bpf_map *map,
+ const void *data, size_t size)
+{
+ if (!map->mmaped || map->libbpf_type == LIBBPF_MAP_KCONFIG ||
+ size != map->def.value_size || map->fd >= 0)
+ return -EINVAL;
+
+ memcpy(map->mmaped, data, size);
+ return 0;
+}
+
+bool bpf_map__is_offload_neutral(const struct bpf_map *map)
{
return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
}
-void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
+bool bpf_map__is_internal(const struct bpf_map *map)
{
- map->map_ifindex = ifindex;
+ return map->libbpf_type != LIBBPF_MAP_UNSPEC;
}
-struct bpf_map *
-bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
+__u32 bpf_map__ifindex(const struct bpf_map *map)
{
- size_t idx;
+ return map->map_ifindex;
+}
+
+int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
+{
+ if (map->fd >= 0)
+ return -EBUSY;
+ map->map_ifindex = ifindex;
+ return 0;
+}
+
+int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
+{
+ if (!bpf_map_type__is_map_in_map(map->def.type)) {
+ pr_warn("error: unsupported map type\n");
+ return -EINVAL;
+ }
+ if (map->inner_map_fd != -1) {
+ pr_warn("error: inner_map_fd already specified\n");
+ return -EINVAL;
+ }
+ map->inner_map_fd = fd;
+ return 0;
+}
+
+static struct bpf_map *
+__bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
+{
+ ssize_t idx;
struct bpf_map *s, *e;
if (!obj || !obj->maps)
@@ -2239,50 +8990,66 @@
s = obj->maps;
e = obj->maps + obj->nr_maps;
- if (prev == NULL)
- return s;
-
- if ((prev < s) || (prev >= e)) {
- pr_warning("error in %s: map handler doesn't belong to object\n",
- __func__);
+ if ((m < s) || (m >= e)) {
+ pr_warn("error in %s: map handler doesn't belong to object\n",
+ __func__);
return NULL;
}
- idx = (prev - obj->maps) + 1;
- if (idx >= obj->nr_maps)
+ idx = (m - obj->maps) + i;
+ if (idx >= obj->nr_maps || idx < 0)
return NULL;
return &obj->maps[idx];
}
struct bpf_map *
-bpf_object__find_map_by_name(struct bpf_object *obj, const char *name)
+bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj)
+{
+ if (prev == NULL)
+ return obj->maps;
+
+ return __bpf_map__iter(prev, obj, 1);
+}
+
+struct bpf_map *
+bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj)
+{
+ if (next == NULL) {
+ if (!obj->nr_maps)
+ return NULL;
+ return obj->maps + obj->nr_maps - 1;
+ }
+
+ return __bpf_map__iter(next, obj, -1);
+}
+
+struct bpf_map *
+bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name)
{
struct bpf_map *pos;
- bpf_map__for_each(pos, obj) {
+ bpf_object__for_each_map(pos, obj) {
if (pos->name && !strcmp(pos->name, name))
return pos;
}
return NULL;
}
+int
+bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name)
+{
+ return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
+}
+
struct bpf_map *
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
{
- int i;
-
- for (i = 0; i < obj->nr_maps; i++) {
- if (obj->maps[i].offset == offset)
- return &obj->maps[i];
- }
- return ERR_PTR(-ENOENT);
+ return ERR_PTR(-ENOTSUP);
}
long libbpf_get_error(const void *ptr)
{
- if (IS_ERR(ptr))
- return PTR_ERR(ptr);
- return 0;
+ return PTR_ERR_OR_ZERO(ptr);
}
int bpf_prog_load(const char *file, enum bpf_prog_type type,
@@ -2303,8 +9070,6 @@
{
struct bpf_object_open_attr open_attr = {};
struct bpf_program *prog, *first_prog = NULL;
- enum bpf_attach_type expected_attach_type;
- enum bpf_prog_type prog_type;
struct bpf_object *obj;
struct bpf_map *map;
int err;
@@ -2322,39 +9087,40 @@
return -ENOENT;
bpf_object__for_each_program(prog, obj) {
+ enum bpf_attach_type attach_type = attr->expected_attach_type;
/*
- * If type is not specified, try to guess it based on
- * section name.
+ * to preserve backwards compatibility, bpf_prog_load treats
+ * attr->prog_type, if specified, as an override to whatever
+ * bpf_object__open guessed
*/
- prog_type = attr->prog_type;
- prog->prog_ifindex = attr->ifindex;
- expected_attach_type = attr->expected_attach_type;
- if (prog_type == BPF_PROG_TYPE_UNSPEC) {
- err = bpf_program__identify_section(prog, &prog_type,
- &expected_attach_type);
- if (err < 0) {
- pr_warning("failed to guess program type based on section name %s\n",
- prog->section_name);
- bpf_object__close(obj);
- return -EINVAL;
- }
+ if (attr->prog_type != BPF_PROG_TYPE_UNSPEC) {
+ bpf_program__set_type(prog, attr->prog_type);
+ bpf_program__set_expected_attach_type(prog,
+ attach_type);
+ }
+ if (bpf_program__get_type(prog) == BPF_PROG_TYPE_UNSPEC) {
+ /*
+ * we haven't guessed from section name and user
+ * didn't provide a fallback type, too bad...
+ */
+ bpf_object__close(obj);
+ return -EINVAL;
}
- bpf_program__set_type(prog, prog_type);
- bpf_program__set_expected_attach_type(prog,
- expected_attach_type);
-
- if (!bpf_program__is_function_storage(prog, obj) && !first_prog)
+ prog->prog_ifindex = attr->ifindex;
+ prog->log_level = attr->log_level;
+ prog->prog_flags |= attr->prog_flags;
+ if (!first_prog)
first_prog = prog;
}
- bpf_map__for_each(map, obj) {
+ bpf_object__for_each_map(map, obj) {
if (!bpf_map__is_offload_neutral(map))
map->map_ifindex = attr->ifindex;
}
if (!first_prog) {
- pr_warning("object file doesn't contain bpf program\n");
+ pr_warn("object file doesn't contain bpf program\n");
bpf_object__close(obj);
return -ENOENT;
}
@@ -2362,7 +9128,7 @@
err = bpf_object__load(obj);
if (err) {
bpf_object__close(obj);
- return -EINVAL;
+ return err;
}
*pobj = obj;
@@ -2370,62 +9136,1817 @@
return 0;
}
-enum bpf_perf_event_ret
-bpf_perf_event_read_simple(void *mem, unsigned long size,
- unsigned long page_size, void **buf, size_t *buf_len,
- bpf_perf_event_print_t fn, void *priv)
+struct bpf_link {
+ int (*detach)(struct bpf_link *link);
+ int (*destroy)(struct bpf_link *link);
+ char *pin_path; /* NULL, if not pinned */
+ int fd; /* hook FD, -1 if not applicable */
+ bool disconnected;
+};
+
+/* Replace link's underlying BPF program with the new one */
+int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog)
{
- volatile struct perf_event_mmap_page *header = mem;
+ return bpf_link_update(bpf_link__fd(link), bpf_program__fd(prog), NULL);
+}
+
+/* Release "ownership" of underlying BPF resource (typically, BPF program
+ * attached to some BPF hook, e.g., tracepoint, kprobe, etc). Disconnected
+ * link, when destructed through bpf_link__destroy() call won't attempt to
+ * detach/unregisted that BPF resource. This is useful in situations where,
+ * say, attached BPF program has to outlive userspace program that attached it
+ * in the system. Depending on type of BPF program, though, there might be
+ * additional steps (like pinning BPF program in BPF FS) necessary to ensure
+ * exit of userspace program doesn't trigger automatic detachment and clean up
+ * inside the kernel.
+ */
+void bpf_link__disconnect(struct bpf_link *link)
+{
+ link->disconnected = true;
+}
+
+int bpf_link__destroy(struct bpf_link *link)
+{
+ int err = 0;
+
+ if (IS_ERR_OR_NULL(link))
+ return 0;
+
+ if (!link->disconnected && link->detach)
+ err = link->detach(link);
+ if (link->destroy)
+ link->destroy(link);
+ if (link->pin_path)
+ free(link->pin_path);
+ free(link);
+
+ return err;
+}
+
+int bpf_link__fd(const struct bpf_link *link)
+{
+ return link->fd;
+}
+
+const char *bpf_link__pin_path(const struct bpf_link *link)
+{
+ return link->pin_path;
+}
+
+static int bpf_link__detach_fd(struct bpf_link *link)
+{
+ return close(link->fd);
+}
+
+struct bpf_link *bpf_link__open(const char *path)
+{
+ struct bpf_link *link;
+ int fd;
+
+ fd = bpf_obj_get(path);
+ if (fd < 0) {
+ fd = -errno;
+ pr_warn("failed to open link at %s: %d\n", path, fd);
+ return ERR_PTR(fd);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link) {
+ close(fd);
+ return ERR_PTR(-ENOMEM);
+ }
+ link->detach = &bpf_link__detach_fd;
+ link->fd = fd;
+
+ link->pin_path = strdup(path);
+ if (!link->pin_path) {
+ bpf_link__destroy(link);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return link;
+}
+
+int bpf_link__detach(struct bpf_link *link)
+{
+ return bpf_link_detach(link->fd) ? -errno : 0;
+}
+
+int bpf_link__pin(struct bpf_link *link, const char *path)
+{
+ int err;
+
+ if (link->pin_path)
+ return -EBUSY;
+ err = make_parent_dir(path);
+ if (err)
+ return err;
+ err = check_path(path);
+ if (err)
+ return err;
+
+ link->pin_path = strdup(path);
+ if (!link->pin_path)
+ return -ENOMEM;
+
+ if (bpf_obj_pin(link->fd, link->pin_path)) {
+ err = -errno;
+ zfree(&link->pin_path);
+ return err;
+ }
+
+ pr_debug("link fd=%d: pinned at %s\n", link->fd, link->pin_path);
+ return 0;
+}
+
+int bpf_link__unpin(struct bpf_link *link)
+{
+ int err;
+
+ if (!link->pin_path)
+ return -EINVAL;
+
+ err = unlink(link->pin_path);
+ if (err != 0)
+ return -errno;
+
+ pr_debug("link fd=%d: unpinned from %s\n", link->fd, link->pin_path);
+ zfree(&link->pin_path);
+ return 0;
+}
+
+static int bpf_link__detach_perf_event(struct bpf_link *link)
+{
+ int err;
+
+ err = ioctl(link->fd, PERF_EVENT_IOC_DISABLE, 0);
+ if (err)
+ err = -errno;
+
+ close(link->fd);
+ return err;
+}
+
+struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog,
+ int pfd)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int prog_fd, err;
+
+ if (pfd < 0) {
+ pr_warn("prog '%s': invalid perf event FD %d\n",
+ prog->name, pfd);
+ return ERR_PTR(-EINVAL);
+ }
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach BPF program w/o FD (did you load it?)\n",
+ prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ link->detach = &bpf_link__detach_perf_event;
+ link->fd = pfd;
+
+ if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) {
+ err = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to attach to pfd %d: %s\n",
+ prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ if (err == -EPROTO)
+ pr_warn("prog '%s': try add PERF_SAMPLE_CALLCHAIN to or remove exclude_callchain_[kernel|user] from pfd %d\n",
+ prog->name, pfd);
+ return ERR_PTR(err);
+ }
+ if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
+ err = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to enable pfd %d: %s\n",
+ prog->name, pfd, libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ return ERR_PTR(err);
+ }
+ return link;
+}
+
+/*
+ * this function is expected to parse integer in the range of [0, 2^31-1] from
+ * given file using scanf format string fmt. If actual parsed value is
+ * negative, the result might be indistinguishable from error
+ */
+static int parse_uint_from_file(const char *file, const char *fmt)
+{
+ char buf[STRERR_BUFSIZE];
+ int err, ret;
+ FILE *f;
+
+ f = fopen(file, "r");
+ if (!f) {
+ err = -errno;
+ pr_debug("failed to open '%s': %s\n", file,
+ libbpf_strerror_r(err, buf, sizeof(buf)));
+ return err;
+ }
+ err = fscanf(f, fmt, &ret);
+ if (err != 1) {
+ err = err == EOF ? -EIO : -errno;
+ pr_debug("failed to parse '%s': %s\n", file,
+ libbpf_strerror_r(err, buf, sizeof(buf)));
+ fclose(f);
+ return err;
+ }
+ fclose(f);
+ return ret;
+}
+
+static int determine_kprobe_perf_type(void)
+{
+ const char *file = "/sys/bus/event_source/devices/kprobe/type";
+
+ return parse_uint_from_file(file, "%d\n");
+}
+
+static int determine_uprobe_perf_type(void)
+{
+ const char *file = "/sys/bus/event_source/devices/uprobe/type";
+
+ return parse_uint_from_file(file, "%d\n");
+}
+
+static int determine_kprobe_retprobe_bit(void)
+{
+ const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe";
+
+ return parse_uint_from_file(file, "config:%d\n");
+}
+
+static int determine_uprobe_retprobe_bit(void)
+{
+ const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe";
+
+ return parse_uint_from_file(file, "config:%d\n");
+}
+
+static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
+ uint64_t offset, int pid)
+{
+ struct perf_event_attr attr = {};
+ char errmsg[STRERR_BUFSIZE];
+ int type, pfd, err;
+
+ type = uprobe ? determine_uprobe_perf_type()
+ : determine_kprobe_perf_type();
+ if (type < 0) {
+ pr_warn("failed to determine %s perf type: %s\n",
+ uprobe ? "uprobe" : "kprobe",
+ libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
+ return type;
+ }
+ if (retprobe) {
+ int bit = uprobe ? determine_uprobe_retprobe_bit()
+ : determine_kprobe_retprobe_bit();
+
+ if (bit < 0) {
+ pr_warn("failed to determine %s retprobe bit: %s\n",
+ uprobe ? "uprobe" : "kprobe",
+ libbpf_strerror_r(bit, errmsg, sizeof(errmsg)));
+ return bit;
+ }
+ attr.config |= 1 << bit;
+ }
+ attr.size = sizeof(attr);
+ attr.type = type;
+ attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */
+ attr.config2 = offset; /* kprobe_addr or probe_offset */
+
+ /* pid filter is meaningful only for uprobes */
+ pfd = syscall(__NR_perf_event_open, &attr,
+ pid < 0 ? -1 : pid /* pid */,
+ pid == -1 ? 0 : -1 /* cpu */,
+ -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
+ if (pfd < 0) {
+ err = -errno;
+ pr_warn("%s perf_event_open() failed: %s\n",
+ uprobe ? "uprobe" : "kprobe",
+ libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ return err;
+ }
+ return pfd;
+}
+
+struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
+ bool retprobe,
+ const char *func_name)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int pfd, err;
+
+ pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
+ 0 /* offset */, -1 /* pid */);
+ if (pfd < 0) {
+ pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
+ prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+ libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(pfd);
+ }
+ link = bpf_program__attach_perf_event(prog, pfd);
+ if (IS_ERR(link)) {
+ close(pfd);
+ err = PTR_ERR(link);
+ pr_warn("prog '%s': failed to attach to %s '%s': %s\n",
+ prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+ libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ return link;
+ }
+ return link;
+}
+
+static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
+ struct bpf_program *prog)
+{
+ const char *func_name;
+ bool retprobe;
+
+ func_name = prog->sec_name + sec->len;
+ retprobe = strcmp(sec->sec, "kretprobe/") == 0;
+
+ return bpf_program__attach_kprobe(prog, retprobe, func_name);
+}
+
+struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
+ bool retprobe, pid_t pid,
+ const char *binary_path,
+ size_t func_offset)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int pfd, err;
+
+ pfd = perf_event_open_probe(true /* uprobe */, retprobe,
+ binary_path, func_offset, pid);
+ if (pfd < 0) {
+ pr_warn("prog '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
+ prog->name, retprobe ? "uretprobe" : "uprobe",
+ binary_path, func_offset,
+ libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(pfd);
+ }
+ link = bpf_program__attach_perf_event(prog, pfd);
+ if (IS_ERR(link)) {
+ close(pfd);
+ err = PTR_ERR(link);
+ pr_warn("prog '%s': failed to attach to %s '%s:0x%zx': %s\n",
+ prog->name, retprobe ? "uretprobe" : "uprobe",
+ binary_path, func_offset,
+ libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ return link;
+ }
+ return link;
+}
+
+static int determine_tracepoint_id(const char *tp_category,
+ const char *tp_name)
+{
+ char file[PATH_MAX];
+ int ret;
+
+ ret = snprintf(file, sizeof(file),
+ "/sys/kernel/debug/tracing/events/%s/%s/id",
+ tp_category, tp_name);
+ if (ret < 0)
+ return -errno;
+ if (ret >= sizeof(file)) {
+ pr_debug("tracepoint %s/%s path is too long\n",
+ tp_category, tp_name);
+ return -E2BIG;
+ }
+ return parse_uint_from_file(file, "%d\n");
+}
+
+static int perf_event_open_tracepoint(const char *tp_category,
+ const char *tp_name)
+{
+ struct perf_event_attr attr = {};
+ char errmsg[STRERR_BUFSIZE];
+ int tp_id, pfd, err;
+
+ tp_id = determine_tracepoint_id(tp_category, tp_name);
+ if (tp_id < 0) {
+ pr_warn("failed to determine tracepoint '%s/%s' perf event ID: %s\n",
+ tp_category, tp_name,
+ libbpf_strerror_r(tp_id, errmsg, sizeof(errmsg)));
+ return tp_id;
+ }
+
+ attr.type = PERF_TYPE_TRACEPOINT;
+ attr.size = sizeof(attr);
+ attr.config = tp_id;
+
+ pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */,
+ -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
+ if (pfd < 0) {
+ err = -errno;
+ pr_warn("tracepoint '%s/%s' perf_event_open() failed: %s\n",
+ tp_category, tp_name,
+ libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ return err;
+ }
+ return pfd;
+}
+
+struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
+ const char *tp_category,
+ const char *tp_name)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int pfd, err;
+
+ pfd = perf_event_open_tracepoint(tp_category, tp_name);
+ if (pfd < 0) {
+ pr_warn("prog '%s': failed to create tracepoint '%s/%s' perf event: %s\n",
+ prog->name, tp_category, tp_name,
+ libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(pfd);
+ }
+ link = bpf_program__attach_perf_event(prog, pfd);
+ if (IS_ERR(link)) {
+ close(pfd);
+ err = PTR_ERR(link);
+ pr_warn("prog '%s': failed to attach to tracepoint '%s/%s': %s\n",
+ prog->name, tp_category, tp_name,
+ libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+ return link;
+ }
+ return link;
+}
+
+static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
+ struct bpf_program *prog)
+{
+ char *sec_name, *tp_cat, *tp_name;
+ struct bpf_link *link;
+
+ sec_name = strdup(prog->sec_name);
+ if (!sec_name)
+ return ERR_PTR(-ENOMEM);
+
+ /* extract "tp/<category>/<name>" */
+ tp_cat = sec_name + sec->len;
+ tp_name = strchr(tp_cat, '/');
+ if (!tp_name) {
+ link = ERR_PTR(-EINVAL);
+ goto out;
+ }
+ *tp_name = '\0';
+ tp_name++;
+
+ link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name);
+out:
+ free(sec_name);
+ return link;
+}
+
+struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
+ const char *tp_name)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int prog_fd, pfd;
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach before loaded\n", prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ link->detach = &bpf_link__detach_fd;
+
+ pfd = bpf_raw_tracepoint_open(tp_name, prog_fd);
+ if (pfd < 0) {
+ pfd = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to attach to raw tracepoint '%s': %s\n",
+ prog->name, tp_name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(pfd);
+ }
+ link->fd = pfd;
+ return link;
+}
+
+static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
+ struct bpf_program *prog)
+{
+ const char *tp_name = prog->sec_name + sec->len;
+
+ return bpf_program__attach_raw_tracepoint(prog, tp_name);
+}
+
+/* Common logic for all BPF program types that attach to a btf_id */
+static struct bpf_link *bpf_program__attach_btf_id(struct bpf_program *prog)
+{
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int prog_fd, pfd;
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach before loaded\n", prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ link->detach = &bpf_link__detach_fd;
+
+ pfd = bpf_raw_tracepoint_open(NULL, prog_fd);
+ if (pfd < 0) {
+ pfd = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to attach: %s\n",
+ prog->name, libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(pfd);
+ }
+ link->fd = pfd;
+ return (struct bpf_link *)link;
+}
+
+struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
+{
+ return bpf_program__attach_btf_id(prog);
+}
+
+struct bpf_link *bpf_program__attach_lsm(struct bpf_program *prog)
+{
+ return bpf_program__attach_btf_id(prog);
+}
+
+static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
+ struct bpf_program *prog)
+{
+ return bpf_program__attach_trace(prog);
+}
+
+static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec,
+ struct bpf_program *prog)
+{
+ return bpf_program__attach_lsm(prog);
+}
+
+static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
+ struct bpf_program *prog)
+{
+ return bpf_program__attach_iter(prog, NULL);
+}
+
+static struct bpf_link *
+bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
+ const char *target_name)
+{
+ DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts,
+ .target_btf_id = btf_id);
+ enum bpf_attach_type attach_type;
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int prog_fd, link_fd;
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach before loaded\n", prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ link->detach = &bpf_link__detach_fd;
+
+ attach_type = bpf_program__get_expected_attach_type(prog);
+ link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts);
+ if (link_fd < 0) {
+ link_fd = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to attach to %s: %s\n",
+ prog->name, target_name,
+ libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(link_fd);
+ }
+ link->fd = link_fd;
+ return link;
+}
+
+struct bpf_link *
+bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd)
+{
+ return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup");
+}
+
+struct bpf_link *
+bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
+{
+ return bpf_program__attach_fd(prog, netns_fd, 0, "netns");
+}
+
+struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex)
+{
+ /* target_fd/target_ifindex use the same field in LINK_CREATE */
+ return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
+}
+
+struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
+ int target_fd,
+ const char *attach_func_name)
+{
+ int btf_id;
+
+ if (!!target_fd != !!attach_func_name) {
+ pr_warn("prog '%s': supply none or both of target_fd and attach_func_name\n",
+ prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (prog->type != BPF_PROG_TYPE_EXT) {
+ pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace",
+ prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (target_fd) {
+ btf_id = libbpf_find_prog_btf_id(attach_func_name, target_fd);
+ if (btf_id < 0)
+ return ERR_PTR(btf_id);
+
+ return bpf_program__attach_fd(prog, target_fd, btf_id, "freplace");
+ } else {
+ /* no target, so use raw_tracepoint_open for compatibility
+ * with old kernels
+ */
+ return bpf_program__attach_trace(prog);
+ }
+}
+
+struct bpf_link *
+bpf_program__attach_iter(struct bpf_program *prog,
+ const struct bpf_iter_attach_opts *opts)
+{
+ DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
+ char errmsg[STRERR_BUFSIZE];
+ struct bpf_link *link;
+ int prog_fd, link_fd;
+ __u32 target_fd = 0;
+
+ if (!OPTS_VALID(opts, bpf_iter_attach_opts))
+ return ERR_PTR(-EINVAL);
+
+ link_create_opts.iter_info = OPTS_GET(opts, link_info, (void *)0);
+ link_create_opts.iter_info_len = OPTS_GET(opts, link_info_len, 0);
+
+ prog_fd = bpf_program__fd(prog);
+ if (prog_fd < 0) {
+ pr_warn("prog '%s': can't attach before loaded\n", prog->name);
+ return ERR_PTR(-EINVAL);
+ }
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ link->detach = &bpf_link__detach_fd;
+
+ link_fd = bpf_link_create(prog_fd, target_fd, BPF_TRACE_ITER,
+ &link_create_opts);
+ if (link_fd < 0) {
+ link_fd = -errno;
+ free(link);
+ pr_warn("prog '%s': failed to attach to iterator: %s\n",
+ prog->name, libbpf_strerror_r(link_fd, errmsg, sizeof(errmsg)));
+ return ERR_PTR(link_fd);
+ }
+ link->fd = link_fd;
+ return link;
+}
+
+struct bpf_link *bpf_program__attach(struct bpf_program *prog)
+{
+ const struct bpf_sec_def *sec_def;
+
+ sec_def = find_sec_def(prog->sec_name);
+ if (!sec_def || !sec_def->attach_fn)
+ return ERR_PTR(-ESRCH);
+
+ return sec_def->attach_fn(sec_def, prog);
+}
+
+static int bpf_link__detach_struct_ops(struct bpf_link *link)
+{
+ __u32 zero = 0;
+
+ if (bpf_map_delete_elem(link->fd, &zero))
+ return -errno;
+
+ return 0;
+}
+
+struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map)
+{
+ struct bpf_struct_ops *st_ops;
+ struct bpf_link *link;
+ __u32 i, zero = 0;
+ int err;
+
+ if (!bpf_map__is_struct_ops(map) || map->fd == -1)
+ return ERR_PTR(-EINVAL);
+
+ link = calloc(1, sizeof(*link));
+ if (!link)
+ return ERR_PTR(-EINVAL);
+
+ st_ops = map->st_ops;
+ for (i = 0; i < btf_vlen(st_ops->type); i++) {
+ struct bpf_program *prog = st_ops->progs[i];
+ void *kern_data;
+ int prog_fd;
+
+ if (!prog)
+ continue;
+
+ prog_fd = bpf_program__fd(prog);
+ kern_data = st_ops->kern_vdata + st_ops->kern_func_off[i];
+ *(unsigned long *)kern_data = prog_fd;
+ }
+
+ err = bpf_map_update_elem(map->fd, &zero, st_ops->kern_vdata, 0);
+ if (err) {
+ err = -errno;
+ free(link);
+ return ERR_PTR(err);
+ }
+
+ link->detach = bpf_link__detach_struct_ops;
+ link->fd = map->fd;
+
+ return link;
+}
+
+enum bpf_perf_event_ret
+bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
+ void **copy_mem, size_t *copy_size,
+ bpf_perf_event_print_t fn, void *private_data)
+{
+ struct perf_event_mmap_page *header = mmap_mem;
+ __u64 data_head = ring_buffer_read_head(header);
__u64 data_tail = header->data_tail;
- __u64 data_head = header->data_head;
- int ret = LIBBPF_PERF_EVENT_ERROR;
- void *base, *begin, *end;
+ void *base = ((__u8 *)header) + page_size;
+ int ret = LIBBPF_PERF_EVENT_CONT;
+ struct perf_event_header *ehdr;
+ size_t ehdr_size;
- asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
- if (data_head == data_tail)
- return LIBBPF_PERF_EVENT_CONT;
+ while (data_head != data_tail) {
+ ehdr = base + (data_tail & (mmap_size - 1));
+ ehdr_size = ehdr->size;
- base = ((char *)header) + page_size;
+ if (((void *)ehdr) + ehdr_size > base + mmap_size) {
+ void *copy_start = ehdr;
+ size_t len_first = base + mmap_size - copy_start;
+ size_t len_secnd = ehdr_size - len_first;
- begin = base + data_tail % size;
- end = base + data_head % size;
-
- while (begin != end) {
- struct perf_event_header *ehdr;
-
- ehdr = begin;
- if (begin + ehdr->size > base + size) {
- long len = base + size - begin;
-
- if (*buf_len < ehdr->size) {
- free(*buf);
- *buf = malloc(ehdr->size);
- if (!*buf) {
+ if (*copy_size < ehdr_size) {
+ free(*copy_mem);
+ *copy_mem = malloc(ehdr_size);
+ if (!*copy_mem) {
+ *copy_size = 0;
ret = LIBBPF_PERF_EVENT_ERROR;
break;
}
- *buf_len = ehdr->size;
+ *copy_size = ehdr_size;
}
- memcpy(*buf, begin, len);
- memcpy(*buf + len, base, ehdr->size - len);
- ehdr = (void *)*buf;
- begin = base + ehdr->size - len;
- } else if (begin + ehdr->size == base + size) {
- begin = base;
- } else {
- begin += ehdr->size;
+ memcpy(*copy_mem, copy_start, len_first);
+ memcpy(*copy_mem + len_first, base, len_secnd);
+ ehdr = *copy_mem;
}
- ret = fn(ehdr, priv);
+ ret = fn(ehdr, private_data);
+ data_tail += ehdr_size;
if (ret != LIBBPF_PERF_EVENT_CONT)
break;
-
- data_tail += ehdr->size;
}
- __sync_synchronize(); /* smp_mb() */
- header->data_tail = data_tail;
-
+ ring_buffer_write_tail(header, data_tail);
return ret;
}
+
+struct perf_buffer;
+
+struct perf_buffer_params {
+ struct perf_event_attr *attr;
+ /* if event_cb is specified, it takes precendence */
+ perf_buffer_event_fn event_cb;
+ /* sample_cb and lost_cb are higher-level common-case callbacks */
+ perf_buffer_sample_fn sample_cb;
+ perf_buffer_lost_fn lost_cb;
+ void *ctx;
+ int cpu_cnt;
+ int *cpus;
+ int *map_keys;
+};
+
+struct perf_cpu_buf {
+ struct perf_buffer *pb;
+ void *base; /* mmap()'ed memory */
+ void *buf; /* for reconstructing segmented data */
+ size_t buf_size;
+ int fd;
+ int cpu;
+ int map_key;
+};
+
+struct perf_buffer {
+ perf_buffer_event_fn event_cb;
+ perf_buffer_sample_fn sample_cb;
+ perf_buffer_lost_fn lost_cb;
+ void *ctx; /* passed into callbacks */
+
+ size_t page_size;
+ size_t mmap_size;
+ struct perf_cpu_buf **cpu_bufs;
+ struct epoll_event *events;
+ int cpu_cnt; /* number of allocated CPU buffers */
+ int epoll_fd; /* perf event FD */
+ int map_fd; /* BPF_MAP_TYPE_PERF_EVENT_ARRAY BPF map FD */
+};
+
+static void perf_buffer__free_cpu_buf(struct perf_buffer *pb,
+ struct perf_cpu_buf *cpu_buf)
+{
+ if (!cpu_buf)
+ return;
+ if (cpu_buf->base &&
+ munmap(cpu_buf->base, pb->mmap_size + pb->page_size))
+ pr_warn("failed to munmap cpu_buf #%d\n", cpu_buf->cpu);
+ if (cpu_buf->fd >= 0) {
+ ioctl(cpu_buf->fd, PERF_EVENT_IOC_DISABLE, 0);
+ close(cpu_buf->fd);
+ }
+ free(cpu_buf->buf);
+ free(cpu_buf);
+}
+
+void perf_buffer__free(struct perf_buffer *pb)
+{
+ int i;
+
+ if (IS_ERR_OR_NULL(pb))
+ return;
+ if (pb->cpu_bufs) {
+ for (i = 0; i < pb->cpu_cnt; i++) {
+ struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
+
+ if (!cpu_buf)
+ continue;
+
+ bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key);
+ perf_buffer__free_cpu_buf(pb, cpu_buf);
+ }
+ free(pb->cpu_bufs);
+ }
+ if (pb->epoll_fd >= 0)
+ close(pb->epoll_fd);
+ free(pb->events);
+ free(pb);
+}
+
+static struct perf_cpu_buf *
+perf_buffer__open_cpu_buf(struct perf_buffer *pb, struct perf_event_attr *attr,
+ int cpu, int map_key)
+{
+ struct perf_cpu_buf *cpu_buf;
+ char msg[STRERR_BUFSIZE];
+ int err;
+
+ cpu_buf = calloc(1, sizeof(*cpu_buf));
+ if (!cpu_buf)
+ return ERR_PTR(-ENOMEM);
+
+ cpu_buf->pb = pb;
+ cpu_buf->cpu = cpu;
+ cpu_buf->map_key = map_key;
+
+ cpu_buf->fd = syscall(__NR_perf_event_open, attr, -1 /* pid */, cpu,
+ -1, PERF_FLAG_FD_CLOEXEC);
+ if (cpu_buf->fd < 0) {
+ err = -errno;
+ pr_warn("failed to open perf buffer event on cpu #%d: %s\n",
+ cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
+ goto error;
+ }
+
+ cpu_buf->base = mmap(NULL, pb->mmap_size + pb->page_size,
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ cpu_buf->fd, 0);
+ if (cpu_buf->base == MAP_FAILED) {
+ cpu_buf->base = NULL;
+ err = -errno;
+ pr_warn("failed to mmap perf buffer on cpu #%d: %s\n",
+ cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
+ goto error;
+ }
+
+ if (ioctl(cpu_buf->fd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
+ err = -errno;
+ pr_warn("failed to enable perf buffer event on cpu #%d: %s\n",
+ cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
+ goto error;
+ }
+
+ return cpu_buf;
+
+error:
+ perf_buffer__free_cpu_buf(pb, cpu_buf);
+ return (struct perf_cpu_buf *)ERR_PTR(err);
+}
+
+static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
+ struct perf_buffer_params *p);
+
+struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt,
+ const struct perf_buffer_opts *opts)
+{
+ struct perf_buffer_params p = {};
+ struct perf_event_attr attr = { 0, };
+
+ attr.config = PERF_COUNT_SW_BPF_OUTPUT;
+ attr.type = PERF_TYPE_SOFTWARE;
+ attr.sample_type = PERF_SAMPLE_RAW;
+ attr.sample_period = 1;
+ attr.wakeup_events = 1;
+
+ p.attr = &attr;
+ p.sample_cb = opts ? opts->sample_cb : NULL;
+ p.lost_cb = opts ? opts->lost_cb : NULL;
+ p.ctx = opts ? opts->ctx : NULL;
+
+ return __perf_buffer__new(map_fd, page_cnt, &p);
+}
+
+struct perf_buffer *
+perf_buffer__new_raw(int map_fd, size_t page_cnt,
+ const struct perf_buffer_raw_opts *opts)
+{
+ struct perf_buffer_params p = {};
+
+ p.attr = opts->attr;
+ p.event_cb = opts->event_cb;
+ p.ctx = opts->ctx;
+ p.cpu_cnt = opts->cpu_cnt;
+ p.cpus = opts->cpus;
+ p.map_keys = opts->map_keys;
+
+ return __perf_buffer__new(map_fd, page_cnt, &p);
+}
+
+static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
+ struct perf_buffer_params *p)
+{
+ const char *online_cpus_file = "/sys/devices/system/cpu/online";
+ struct bpf_map_info map;
+ char msg[STRERR_BUFSIZE];
+ struct perf_buffer *pb;
+ bool *online = NULL;
+ __u32 map_info_len;
+ int err, i, j, n;
+
+ if (page_cnt & (page_cnt - 1)) {
+ pr_warn("page count should be power of two, but is %zu\n",
+ page_cnt);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* best-effort sanity checks */
+ memset(&map, 0, sizeof(map));
+ map_info_len = sizeof(map);
+ err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len);
+ if (err) {
+ err = -errno;
+ /* if BPF_OBJ_GET_INFO_BY_FD is supported, will return
+ * -EBADFD, -EFAULT, or -E2BIG on real error
+ */
+ if (err != -EINVAL) {
+ pr_warn("failed to get map info for map FD %d: %s\n",
+ map_fd, libbpf_strerror_r(err, msg, sizeof(msg)));
+ return ERR_PTR(err);
+ }
+ pr_debug("failed to get map info for FD %d; API not supported? Ignoring...\n",
+ map_fd);
+ } else {
+ if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
+ pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
+ map.name);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ pb = calloc(1, sizeof(*pb));
+ if (!pb)
+ return ERR_PTR(-ENOMEM);
+
+ pb->event_cb = p->event_cb;
+ pb->sample_cb = p->sample_cb;
+ pb->lost_cb = p->lost_cb;
+ pb->ctx = p->ctx;
+
+ pb->page_size = getpagesize();
+ pb->mmap_size = pb->page_size * page_cnt;
+ pb->map_fd = map_fd;
+
+ pb->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
+ if (pb->epoll_fd < 0) {
+ err = -errno;
+ pr_warn("failed to create epoll instance: %s\n",
+ libbpf_strerror_r(err, msg, sizeof(msg)));
+ goto error;
+ }
+
+ if (p->cpu_cnt > 0) {
+ pb->cpu_cnt = p->cpu_cnt;
+ } else {
+ pb->cpu_cnt = libbpf_num_possible_cpus();
+ if (pb->cpu_cnt < 0) {
+ err = pb->cpu_cnt;
+ goto error;
+ }
+ if (map.max_entries && map.max_entries < pb->cpu_cnt)
+ pb->cpu_cnt = map.max_entries;
+ }
+
+ pb->events = calloc(pb->cpu_cnt, sizeof(*pb->events));
+ if (!pb->events) {
+ err = -ENOMEM;
+ pr_warn("failed to allocate events: out of memory\n");
+ goto error;
+ }
+ pb->cpu_bufs = calloc(pb->cpu_cnt, sizeof(*pb->cpu_bufs));
+ if (!pb->cpu_bufs) {
+ err = -ENOMEM;
+ pr_warn("failed to allocate buffers: out of memory\n");
+ goto error;
+ }
+
+ err = parse_cpu_mask_file(online_cpus_file, &online, &n);
+ if (err) {
+ pr_warn("failed to get online CPU mask: %d\n", err);
+ goto error;
+ }
+
+ for (i = 0, j = 0; i < pb->cpu_cnt; i++) {
+ struct perf_cpu_buf *cpu_buf;
+ int cpu, map_key;
+
+ cpu = p->cpu_cnt > 0 ? p->cpus[i] : i;
+ map_key = p->cpu_cnt > 0 ? p->map_keys[i] : i;
+
+ /* in case user didn't explicitly requested particular CPUs to
+ * be attached to, skip offline/not present CPUs
+ */
+ if (p->cpu_cnt <= 0 && (cpu >= n || !online[cpu]))
+ continue;
+
+ cpu_buf = perf_buffer__open_cpu_buf(pb, p->attr, cpu, map_key);
+ if (IS_ERR(cpu_buf)) {
+ err = PTR_ERR(cpu_buf);
+ goto error;
+ }
+
+ pb->cpu_bufs[j] = cpu_buf;
+
+ err = bpf_map_update_elem(pb->map_fd, &map_key,
+ &cpu_buf->fd, 0);
+ if (err) {
+ err = -errno;
+ pr_warn("failed to set cpu #%d, key %d -> perf FD %d: %s\n",
+ cpu, map_key, cpu_buf->fd,
+ libbpf_strerror_r(err, msg, sizeof(msg)));
+ goto error;
+ }
+
+ pb->events[j].events = EPOLLIN;
+ pb->events[j].data.ptr = cpu_buf;
+ if (epoll_ctl(pb->epoll_fd, EPOLL_CTL_ADD, cpu_buf->fd,
+ &pb->events[j]) < 0) {
+ err = -errno;
+ pr_warn("failed to epoll_ctl cpu #%d perf FD %d: %s\n",
+ cpu, cpu_buf->fd,
+ libbpf_strerror_r(err, msg, sizeof(msg)));
+ goto error;
+ }
+ j++;
+ }
+ pb->cpu_cnt = j;
+ free(online);
+
+ return pb;
+
+error:
+ free(online);
+ if (pb)
+ perf_buffer__free(pb);
+ return ERR_PTR(err);
+}
+
+struct perf_sample_raw {
+ struct perf_event_header header;
+ uint32_t size;
+ char data[];
+};
+
+struct perf_sample_lost {
+ struct perf_event_header header;
+ uint64_t id;
+ uint64_t lost;
+ uint64_t sample_id;
+};
+
+static enum bpf_perf_event_ret
+perf_buffer__process_record(struct perf_event_header *e, void *ctx)
+{
+ struct perf_cpu_buf *cpu_buf = ctx;
+ struct perf_buffer *pb = cpu_buf->pb;
+ void *data = e;
+
+ /* user wants full control over parsing perf event */
+ if (pb->event_cb)
+ return pb->event_cb(pb->ctx, cpu_buf->cpu, e);
+
+ switch (e->type) {
+ case PERF_RECORD_SAMPLE: {
+ struct perf_sample_raw *s = data;
+
+ if (pb->sample_cb)
+ pb->sample_cb(pb->ctx, cpu_buf->cpu, s->data, s->size);
+ break;
+ }
+ case PERF_RECORD_LOST: {
+ struct perf_sample_lost *s = data;
+
+ if (pb->lost_cb)
+ pb->lost_cb(pb->ctx, cpu_buf->cpu, s->lost);
+ break;
+ }
+ default:
+ pr_warn("unknown perf sample type %d\n", e->type);
+ return LIBBPF_PERF_EVENT_ERROR;
+ }
+ return LIBBPF_PERF_EVENT_CONT;
+}
+
+static int perf_buffer__process_records(struct perf_buffer *pb,
+ struct perf_cpu_buf *cpu_buf)
+{
+ enum bpf_perf_event_ret ret;
+
+ ret = bpf_perf_event_read_simple(cpu_buf->base, pb->mmap_size,
+ pb->page_size, &cpu_buf->buf,
+ &cpu_buf->buf_size,
+ perf_buffer__process_record, cpu_buf);
+ if (ret != LIBBPF_PERF_EVENT_CONT)
+ return ret;
+ return 0;
+}
+
+int perf_buffer__epoll_fd(const struct perf_buffer *pb)
+{
+ return pb->epoll_fd;
+}
+
+int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms)
+{
+ int i, cnt, err;
+
+ cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms);
+ for (i = 0; i < cnt; i++) {
+ struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr;
+
+ err = perf_buffer__process_records(pb, cpu_buf);
+ if (err) {
+ pr_warn("error while processing records: %d\n", err);
+ return err;
+ }
+ }
+ return cnt < 0 ? -errno : cnt;
+}
+
+/* Return number of PERF_EVENT_ARRAY map slots set up by this perf_buffer
+ * manager.
+ */
+size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb)
+{
+ return pb->cpu_cnt;
+}
+
+/*
+ * Return perf_event FD of a ring buffer in *buf_idx* slot of
+ * PERF_EVENT_ARRAY BPF map. This FD can be polled for new data using
+ * select()/poll()/epoll() Linux syscalls.
+ */
+int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx)
+{
+ struct perf_cpu_buf *cpu_buf;
+
+ if (buf_idx >= pb->cpu_cnt)
+ return -EINVAL;
+
+ cpu_buf = pb->cpu_bufs[buf_idx];
+ if (!cpu_buf)
+ return -ENOENT;
+
+ return cpu_buf->fd;
+}
+
+/*
+ * Consume data from perf ring buffer corresponding to slot *buf_idx* in
+ * PERF_EVENT_ARRAY BPF map without waiting/polling. If there is no data to
+ * consume, do nothing and return success.
+ * Returns:
+ * - 0 on success;
+ * - <0 on failure.
+ */
+int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx)
+{
+ struct perf_cpu_buf *cpu_buf;
+
+ if (buf_idx >= pb->cpu_cnt)
+ return -EINVAL;
+
+ cpu_buf = pb->cpu_bufs[buf_idx];
+ if (!cpu_buf)
+ return -ENOENT;
+
+ return perf_buffer__process_records(pb, cpu_buf);
+}
+
+int perf_buffer__consume(struct perf_buffer *pb)
+{
+ int i, err;
+
+ for (i = 0; i < pb->cpu_cnt; i++) {
+ struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
+
+ if (!cpu_buf)
+ continue;
+
+ err = perf_buffer__process_records(pb, cpu_buf);
+ if (err) {
+ pr_warn("perf_buffer: failed to process records in buffer #%d: %d\n", i, err);
+ return err;
+ }
+ }
+ return 0;
+}
+
+struct bpf_prog_info_array_desc {
+ int array_offset; /* e.g. offset of jited_prog_insns */
+ int count_offset; /* e.g. offset of jited_prog_len */
+ int size_offset; /* > 0: offset of rec size,
+ * < 0: fix size of -size_offset
+ */
+};
+
+static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
+ [BPF_PROG_INFO_JITED_INSNS] = {
+ offsetof(struct bpf_prog_info, jited_prog_insns),
+ offsetof(struct bpf_prog_info, jited_prog_len),
+ -1,
+ },
+ [BPF_PROG_INFO_XLATED_INSNS] = {
+ offsetof(struct bpf_prog_info, xlated_prog_insns),
+ offsetof(struct bpf_prog_info, xlated_prog_len),
+ -1,
+ },
+ [BPF_PROG_INFO_MAP_IDS] = {
+ offsetof(struct bpf_prog_info, map_ids),
+ offsetof(struct bpf_prog_info, nr_map_ids),
+ -(int)sizeof(__u32),
+ },
+ [BPF_PROG_INFO_JITED_KSYMS] = {
+ offsetof(struct bpf_prog_info, jited_ksyms),
+ offsetof(struct bpf_prog_info, nr_jited_ksyms),
+ -(int)sizeof(__u64),
+ },
+ [BPF_PROG_INFO_JITED_FUNC_LENS] = {
+ offsetof(struct bpf_prog_info, jited_func_lens),
+ offsetof(struct bpf_prog_info, nr_jited_func_lens),
+ -(int)sizeof(__u32),
+ },
+ [BPF_PROG_INFO_FUNC_INFO] = {
+ offsetof(struct bpf_prog_info, func_info),
+ offsetof(struct bpf_prog_info, nr_func_info),
+ offsetof(struct bpf_prog_info, func_info_rec_size),
+ },
+ [BPF_PROG_INFO_LINE_INFO] = {
+ offsetof(struct bpf_prog_info, line_info),
+ offsetof(struct bpf_prog_info, nr_line_info),
+ offsetof(struct bpf_prog_info, line_info_rec_size),
+ },
+ [BPF_PROG_INFO_JITED_LINE_INFO] = {
+ offsetof(struct bpf_prog_info, jited_line_info),
+ offsetof(struct bpf_prog_info, nr_jited_line_info),
+ offsetof(struct bpf_prog_info, jited_line_info_rec_size),
+ },
+ [BPF_PROG_INFO_PROG_TAGS] = {
+ offsetof(struct bpf_prog_info, prog_tags),
+ offsetof(struct bpf_prog_info, nr_prog_tags),
+ -(int)sizeof(__u8) * BPF_TAG_SIZE,
+ },
+
+};
+
+static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info,
+ int offset)
+{
+ __u32 *array = (__u32 *)info;
+
+ if (offset >= 0)
+ return array[offset / sizeof(__u32)];
+ return -(int)offset;
+}
+
+static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info,
+ int offset)
+{
+ __u64 *array = (__u64 *)info;
+
+ if (offset >= 0)
+ return array[offset / sizeof(__u64)];
+ return -(int)offset;
+}
+
+static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
+ __u32 val)
+{
+ __u32 *array = (__u32 *)info;
+
+ if (offset >= 0)
+ array[offset / sizeof(__u32)] = val;
+}
+
+static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
+ __u64 val)
+{
+ __u64 *array = (__u64 *)info;
+
+ if (offset >= 0)
+ array[offset / sizeof(__u64)] = val;
+}
+
+struct bpf_prog_info_linear *
+bpf_program__get_prog_info_linear(int fd, __u64 arrays)
+{
+ struct bpf_prog_info_linear *info_linear;
+ struct bpf_prog_info info = {};
+ __u32 info_len = sizeof(info);
+ __u32 data_len = 0;
+ int i, err;
+ void *ptr;
+
+ if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
+ return ERR_PTR(-EINVAL);
+
+ /* step 1: get array dimensions */
+ err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+ if (err) {
+ pr_debug("can't get prog info: %s", strerror(errno));
+ return ERR_PTR(-EFAULT);
+ }
+
+ /* step 2: calculate total size of all arrays */
+ for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+ bool include_array = (arrays & (1UL << i)) > 0;
+ struct bpf_prog_info_array_desc *desc;
+ __u32 count, size;
+
+ desc = bpf_prog_info_array_desc + i;
+
+ /* kernel is too old to support this field */
+ if (info_len < desc->array_offset + sizeof(__u32) ||
+ info_len < desc->count_offset + sizeof(__u32) ||
+ (desc->size_offset > 0 && info_len < desc->size_offset))
+ include_array = false;
+
+ if (!include_array) {
+ arrays &= ~(1UL << i); /* clear the bit */
+ continue;
+ }
+
+ count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+ size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+
+ data_len += count * size;
+ }
+
+ /* step 3: allocate continuous memory */
+ data_len = roundup(data_len, sizeof(__u64));
+ info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
+ if (!info_linear)
+ return ERR_PTR(-ENOMEM);
+
+ /* step 4: fill data to info_linear->info */
+ info_linear->arrays = arrays;
+ memset(&info_linear->info, 0, sizeof(info));
+ ptr = info_linear->data;
+
+ for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+ struct bpf_prog_info_array_desc *desc;
+ __u32 count, size;
+
+ if ((arrays & (1UL << i)) == 0)
+ continue;
+
+ desc = bpf_prog_info_array_desc + i;
+ count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+ size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+ bpf_prog_info_set_offset_u32(&info_linear->info,
+ desc->count_offset, count);
+ bpf_prog_info_set_offset_u32(&info_linear->info,
+ desc->size_offset, size);
+ bpf_prog_info_set_offset_u64(&info_linear->info,
+ desc->array_offset,
+ ptr_to_u64(ptr));
+ ptr += count * size;
+ }
+
+ /* step 5: call syscall again to get required arrays */
+ err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
+ if (err) {
+ pr_debug("can't get prog info: %s", strerror(errno));
+ free(info_linear);
+ return ERR_PTR(-EFAULT);
+ }
+
+ /* step 6: verify the data */
+ for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+ struct bpf_prog_info_array_desc *desc;
+ __u32 v1, v2;
+
+ if ((arrays & (1UL << i)) == 0)
+ continue;
+
+ desc = bpf_prog_info_array_desc + i;
+ v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+ v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
+ desc->count_offset);
+ if (v1 != v2)
+ pr_warn("%s: mismatch in element count\n", __func__);
+
+ v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+ v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
+ desc->size_offset);
+ if (v1 != v2)
+ pr_warn("%s: mismatch in rec size\n", __func__);
+ }
+
+ /* step 7: update info_len and data_len */
+ info_linear->info_len = sizeof(struct bpf_prog_info);
+ info_linear->data_len = data_len;
+
+ return info_linear;
+}
+
+void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
+{
+ int i;
+
+ for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+ struct bpf_prog_info_array_desc *desc;
+ __u64 addr, offs;
+
+ if ((info_linear->arrays & (1UL << i)) == 0)
+ continue;
+
+ desc = bpf_prog_info_array_desc + i;
+ addr = bpf_prog_info_read_offset_u64(&info_linear->info,
+ desc->array_offset);
+ offs = addr - ptr_to_u64(info_linear->data);
+ bpf_prog_info_set_offset_u64(&info_linear->info,
+ desc->array_offset, offs);
+ }
+}
+
+void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
+{
+ int i;
+
+ for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+ struct bpf_prog_info_array_desc *desc;
+ __u64 addr, offs;
+
+ if ((info_linear->arrays & (1UL << i)) == 0)
+ continue;
+
+ desc = bpf_prog_info_array_desc + i;
+ offs = bpf_prog_info_read_offset_u64(&info_linear->info,
+ desc->array_offset);
+ addr = offs + ptr_to_u64(info_linear->data);
+ bpf_prog_info_set_offset_u64(&info_linear->info,
+ desc->array_offset, addr);
+ }
+}
+
+int bpf_program__set_attach_target(struct bpf_program *prog,
+ int attach_prog_fd,
+ const char *attach_func_name)
+{
+ int btf_id;
+
+ if (!prog || attach_prog_fd < 0 || !attach_func_name)
+ return -EINVAL;
+
+ if (attach_prog_fd)
+ btf_id = libbpf_find_prog_btf_id(attach_func_name,
+ attach_prog_fd);
+ else
+ btf_id = libbpf_find_vmlinux_btf_id(attach_func_name,
+ prog->expected_attach_type);
+
+ if (btf_id < 0)
+ return btf_id;
+
+ prog->attach_btf_id = btf_id;
+ prog->attach_prog_fd = attach_prog_fd;
+ return 0;
+}
+
+int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz)
+{
+ int err = 0, n, len, start, end = -1;
+ bool *tmp;
+
+ *mask = NULL;
+ *mask_sz = 0;
+
+ /* Each sub string separated by ',' has format \d+-\d+ or \d+ */
+ while (*s) {
+ if (*s == ',' || *s == '\n') {
+ s++;
+ continue;
+ }
+ n = sscanf(s, "%d%n-%d%n", &start, &len, &end, &len);
+ if (n <= 0 || n > 2) {
+ pr_warn("Failed to get CPU range %s: %d\n", s, n);
+ err = -EINVAL;
+ goto cleanup;
+ } else if (n == 1) {
+ end = start;
+ }
+ if (start < 0 || start > end) {
+ pr_warn("Invalid CPU range [%d,%d] in %s\n",
+ start, end, s);
+ err = -EINVAL;
+ goto cleanup;
+ }
+ tmp = realloc(*mask, end + 1);
+ if (!tmp) {
+ err = -ENOMEM;
+ goto cleanup;
+ }
+ *mask = tmp;
+ memset(tmp + *mask_sz, 0, start - *mask_sz);
+ memset(tmp + start, 1, end - start + 1);
+ *mask_sz = end + 1;
+ s += len;
+ }
+ if (!*mask_sz) {
+ pr_warn("Empty CPU range\n");
+ return -EINVAL;
+ }
+ return 0;
+cleanup:
+ free(*mask);
+ *mask = NULL;
+ return err;
+}
+
+int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz)
+{
+ int fd, err = 0, len;
+ char buf[128];
+
+ fd = open(fcpu, O_RDONLY);
+ if (fd < 0) {
+ err = -errno;
+ pr_warn("Failed to open cpu mask file %s: %d\n", fcpu, err);
+ return err;
+ }
+ len = read(fd, buf, sizeof(buf));
+ close(fd);
+ if (len <= 0) {
+ err = len ? -errno : -EINVAL;
+ pr_warn("Failed to read cpu mask from %s: %d\n", fcpu, err);
+ return err;
+ }
+ if (len >= sizeof(buf)) {
+ pr_warn("CPU mask is too big in file %s\n", fcpu);
+ return -E2BIG;
+ }
+ buf[len] = '\0';
+
+ return parse_cpu_mask_str(buf, mask, mask_sz);
+}
+
+int libbpf_num_possible_cpus(void)
+{
+ static const char *fcpu = "/sys/devices/system/cpu/possible";
+ static int cpus;
+ int err, n, i, tmp_cpus;
+ bool *mask;
+
+ tmp_cpus = READ_ONCE(cpus);
+ if (tmp_cpus > 0)
+ return tmp_cpus;
+
+ err = parse_cpu_mask_file(fcpu, &mask, &n);
+ if (err)
+ return err;
+
+ tmp_cpus = 0;
+ for (i = 0; i < n; i++) {
+ if (mask[i])
+ tmp_cpus++;
+ }
+ free(mask);
+
+ WRITE_ONCE(cpus, tmp_cpus);
+ return tmp_cpus;
+}
+
+int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
+ const struct bpf_object_open_opts *opts)
+{
+ DECLARE_LIBBPF_OPTS(bpf_object_open_opts, skel_opts,
+ .object_name = s->name,
+ );
+ struct bpf_object *obj;
+ int i;
+
+ /* Attempt to preserve opts->object_name, unless overriden by user
+ * explicitly. Overwriting object name for skeletons is discouraged,
+ * as it breaks global data maps, because they contain object name
+ * prefix as their own map name prefix. When skeleton is generated,
+ * bpftool is making an assumption that this name will stay the same.
+ */
+ if (opts) {
+ memcpy(&skel_opts, opts, sizeof(*opts));
+ if (!opts->object_name)
+ skel_opts.object_name = s->name;
+ }
+
+ obj = bpf_object__open_mem(s->data, s->data_sz, &skel_opts);
+ if (IS_ERR(obj)) {
+ pr_warn("failed to initialize skeleton BPF object '%s': %ld\n",
+ s->name, PTR_ERR(obj));
+ return PTR_ERR(obj);
+ }
+
+ *s->obj = obj;
+
+ for (i = 0; i < s->map_cnt; i++) {
+ struct bpf_map **map = s->maps[i].map;
+ const char *name = s->maps[i].name;
+ void **mmaped = s->maps[i].mmaped;
+
+ *map = bpf_object__find_map_by_name(obj, name);
+ if (!*map) {
+ pr_warn("failed to find skeleton map '%s'\n", name);
+ return -ESRCH;
+ }
+
+ /* externs shouldn't be pre-setup from user code */
+ if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG)
+ *mmaped = (*map)->mmaped;
+ }
+
+ for (i = 0; i < s->prog_cnt; i++) {
+ struct bpf_program **prog = s->progs[i].prog;
+ const char *name = s->progs[i].name;
+
+ *prog = bpf_object__find_program_by_name(obj, name);
+ if (!*prog) {
+ pr_warn("failed to find skeleton program '%s'\n", name);
+ return -ESRCH;
+ }
+ }
+
+ return 0;
+}
+
+int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
+{
+ int i, err;
+
+ err = bpf_object__load(*s->obj);
+ if (err) {
+ pr_warn("failed to load BPF skeleton '%s': %d\n", s->name, err);
+ return err;
+ }
+
+ for (i = 0; i < s->map_cnt; i++) {
+ struct bpf_map *map = *s->maps[i].map;
+ size_t mmap_sz = bpf_map_mmap_sz(map);
+ int prot, map_fd = bpf_map__fd(map);
+ void **mmaped = s->maps[i].mmaped;
+
+ if (!mmaped)
+ continue;
+
+ if (!(map->def.map_flags & BPF_F_MMAPABLE)) {
+ *mmaped = NULL;
+ continue;
+ }
+
+ if (map->def.map_flags & BPF_F_RDONLY_PROG)
+ prot = PROT_READ;
+ else
+ prot = PROT_READ | PROT_WRITE;
+
+ /* Remap anonymous mmap()-ed "map initialization image" as
+ * a BPF map-backed mmap()-ed memory, but preserving the same
+ * memory address. This will cause kernel to change process'
+ * page table to point to a different piece of kernel memory,
+ * but from userspace point of view memory address (and its
+ * contents, being identical at this point) will stay the
+ * same. This mapping will be released by bpf_object__close()
+ * as per normal clean up procedure, so we don't need to worry
+ * about it from skeleton's clean up perspective.
+ */
+ *mmaped = mmap(map->mmaped, mmap_sz, prot,
+ MAP_SHARED | MAP_FIXED, map_fd, 0);
+ if (*mmaped == MAP_FAILED) {
+ err = -errno;
+ *mmaped = NULL;
+ pr_warn("failed to re-mmap() map '%s': %d\n",
+ bpf_map__name(map), err);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
+{
+ int i;
+
+ for (i = 0; i < s->prog_cnt; i++) {
+ struct bpf_program *prog = *s->progs[i].prog;
+ struct bpf_link **link = s->progs[i].link;
+ const struct bpf_sec_def *sec_def;
+
+ if (!prog->load)
+ continue;
+
+ sec_def = find_sec_def(prog->sec_name);
+ if (!sec_def || !sec_def->attach_fn)
+ continue;
+
+ *link = sec_def->attach_fn(sec_def, prog);
+ if (IS_ERR(*link)) {
+ pr_warn("failed to auto-attach program '%s': %ld\n",
+ bpf_program__name(prog), PTR_ERR(*link));
+ return PTR_ERR(*link);
+ }
+ }
+
+ return 0;
+}
+
+void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
+{
+ int i;
+
+ for (i = 0; i < s->prog_cnt; i++) {
+ struct bpf_link **link = s->progs[i].link;
+
+ bpf_link__destroy(*link);
+ *link = NULL;
+ }
+}
+
+void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
+{
+ if (!s)
+ return;
+
+ if (s->progs)
+ bpf_object__detach_skeleton(s);
+ if (s->obj)
+ bpf_object__close(*s->obj);
+ free(s->maps);
+ free(s->progs);
+ free(s);
+}
--
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