From e636c8d336489bf3eed5878299e6cc045bbad077 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:17:29 +0000
Subject: [PATCH] debug lk
---
kernel/tools/objtool/check.c | 2912 ++++++++++++++++++++++++++++++++++++++++++++---------------
1 files changed, 2,163 insertions(+), 749 deletions(-)
diff --git a/kernel/tools/objtool/check.c b/kernel/tools/objtool/check.c
index c0ab273..d2bd5c0 100644
--- a/kernel/tools/objtool/check.c
+++ b/kernel/tools/objtool/check.c
@@ -1,51 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
- *
- * 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <stdlib.h>
+#include <inttypes.h>
+#include <sys/mman.h>
#include "builtin.h"
-#include "check.h"
-#include "elf.h"
-#include "special.h"
+#include "cfi.h"
#include "arch.h"
+#include "check.h"
+#include "special.h"
#include "warn.h"
+#include "arch_elf.h"
+#include <linux/objtool.h>
#include <linux/hashtable.h>
#include <linux/kernel.h>
-
-#define FAKE_JUMP_OFFSET -1
+#include <linux/static_call_types.h>
struct alternative {
struct list_head list;
struct instruction *insn;
+ bool skip_orig;
};
-const char *objname;
-struct cfi_state initial_func_cfi;
+static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache;
+
+static struct cfi_init_state initial_func_cfi;
+static struct cfi_state init_cfi;
+static struct cfi_state func_cfi;
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset)
{
struct instruction *insn;
- hash_for_each_possible(file->insn_hash, insn, hash, offset)
+ hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) {
if (insn->sec == sec && insn->offset == offset)
return insn;
+ }
return NULL;
}
@@ -81,22 +77,33 @@
return find_insn(file, func->cfunc->sec, func->cfunc->offset);
}
-#define func_for_each_insn_all(file, func, insn) \
+static struct instruction *prev_insn_same_sym(struct objtool_file *file,
+ struct instruction *insn)
+{
+ struct instruction *prev = list_prev_entry(insn, list);
+
+ if (&prev->list != &file->insn_list && prev->func == insn->func)
+ return prev;
+
+ return NULL;
+}
+
+#define func_for_each_insn(file, func, insn) \
for (insn = find_insn(file, func->sec, func->offset); \
insn; \
insn = next_insn_same_func(file, insn))
-#define func_for_each_insn(file, func, insn) \
- for (insn = find_insn(file, func->sec, func->offset); \
+#define sym_for_each_insn(file, sym, insn) \
+ for (insn = find_insn(file, sym->sec, sym->offset); \
insn && &insn->list != &file->insn_list && \
- insn->sec == func->sec && \
- insn->offset < func->offset + func->len; \
+ insn->sec == sym->sec && \
+ insn->offset < sym->offset + sym->len; \
insn = list_next_entry(insn, list))
-#define func_for_each_insn_continue_reverse(file, func, insn) \
+#define sym_for_each_insn_continue_reverse(file, sym, insn) \
for (insn = list_prev_entry(insn, list); \
&insn->list != &file->insn_list && \
- insn->sec == func->sec && insn->offset >= func->offset; \
+ insn->sec == sym->sec && insn->offset >= sym->offset; \
insn = list_prev_entry(insn, list))
#define sec_for_each_insn_from(file, insn) \
@@ -106,27 +113,34 @@
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))
-/*
- * Check if the function has been manually whitelisted with the
- * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted
- * due to its use of a context switching instruction.
- */
-static bool ignore_func(struct objtool_file *file, struct symbol *func)
+static bool is_jump_table_jump(struct instruction *insn)
{
- struct rela *rela;
+ struct alt_group *alt_group = insn->alt_group;
- /* check for STACK_FRAME_NON_STANDARD */
- if (file->whitelist && file->whitelist->rela)
- list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) {
- if (rela->sym->type == STT_SECTION &&
- rela->sym->sec == func->sec &&
- rela->addend == func->offset)
- return true;
- if (rela->sym->type == STT_FUNC && rela->sym == func)
- return true;
- }
+ if (insn->jump_table)
+ return true;
- return false;
+ /* Retpoline alternative for a jump table? */
+ return alt_group && alt_group->orig_group &&
+ alt_group->orig_group->first_insn->jump_table;
+}
+
+static bool is_sibling_call(struct instruction *insn)
+{
+ /*
+ * Assume only ELF functions can make sibling calls. This ensures
+ * sibling call detection consistency between vmlinux.o and individual
+ * objects.
+ */
+ if (!insn->func)
+ return false;
+
+ /* An indirect jump is either a sibling call or a jump to a table. */
+ if (insn->type == INSN_JUMP_DYNAMIC)
+ return !is_jump_table_jump(insn);
+
+ /* add_jump_destinations() sets insn->call_dest for sibling calls. */
+ return (is_static_jump(insn) && insn->call_dest);
}
/*
@@ -137,14 +151,9 @@
*
* For local functions, we have to detect them manually by simply looking for
* the lack of a return instruction.
- *
- * Returns:
- * -1: error
- * 0: no dead end
- * 1: dead end
*/
-static int __dead_end_function(struct objtool_file *file, struct symbol *func,
- int recursion)
+static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
+ int recursion)
{
int i;
struct instruction *insn;
@@ -159,99 +168,182 @@
"panic",
"do_exit",
"do_task_dead",
+ "make_task_dead",
"__module_put_and_exit",
"complete_and_exit",
- "kvm_spurious_fault",
"__reiserfs_panic",
"lbug_with_loc",
"fortify_panic",
"usercopy_abort",
"machine_real_restart",
- "rewind_stack_do_exit",
+ "rewind_stack_and_make_dead",
+ "kunit_try_catch_throw",
+ "xen_start_kernel",
+ "cpu_bringup_and_idle",
+ "stop_this_cpu",
};
+ if (!func)
+ return false;
+
if (func->bind == STB_WEAK)
- return 0;
+ return false;
if (func->bind == STB_GLOBAL)
for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
if (!strcmp(func->name, global_noreturns[i]))
- return 1;
+ return true;
if (!func->len)
- return 0;
+ return false;
insn = find_insn(file, func->sec, func->offset);
- if (!insn->func)
- return 0;
+ if (!insn || !insn->func)
+ return false;
- func_for_each_insn_all(file, func, insn) {
+ func_for_each_insn(file, func, insn) {
empty = false;
if (insn->type == INSN_RETURN)
- return 0;
+ return false;
}
if (empty)
- return 0;
+ return false;
/*
* A function can have a sibling call instead of a return. In that
* case, the function's dead-end status depends on whether the target
* of the sibling call returns.
*/
- func_for_each_insn_all(file, func, insn) {
- if (insn->type == INSN_JUMP_UNCONDITIONAL) {
+ func_for_each_insn(file, func, insn) {
+ if (is_sibling_call(insn)) {
struct instruction *dest = insn->jump_dest;
if (!dest)
/* sibling call to another file */
- return 0;
+ return false;
- if (dest->func && dest->func->pfunc != insn->func->pfunc) {
-
- /* local sibling call */
- if (recursion == 5) {
- /*
- * Infinite recursion: two functions
- * have sibling calls to each other.
- * This is a very rare case. It means
- * they aren't dead ends.
- */
- return 0;
- }
-
- return __dead_end_function(file, dest->func,
- recursion + 1);
+ /* local sibling call */
+ if (recursion == 5) {
+ /*
+ * Infinite recursion: two functions have
+ * sibling calls to each other. This is a very
+ * rare case. It means they aren't dead ends.
+ */
+ return false;
}
- }
- if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts))
- /* sibling call */
- return 0;
+ return __dead_end_function(file, dest->func, recursion+1);
+ }
}
- return 1;
+ return true;
}
-static int dead_end_function(struct objtool_file *file, struct symbol *func)
+static bool dead_end_function(struct objtool_file *file, struct symbol *func)
{
return __dead_end_function(file, func, 0);
}
-static void clear_insn_state(struct insn_state *state)
+static void init_cfi_state(struct cfi_state *cfi)
{
int i;
- memset(state, 0, sizeof(*state));
- state->cfa.base = CFI_UNDEFINED;
for (i = 0; i < CFI_NUM_REGS; i++) {
- state->regs[i].base = CFI_UNDEFINED;
- state->vals[i].base = CFI_UNDEFINED;
+ cfi->regs[i].base = CFI_UNDEFINED;
+ cfi->vals[i].base = CFI_UNDEFINED;
}
- state->drap_reg = CFI_UNDEFINED;
- state->drap_offset = -1;
+ cfi->cfa.base = CFI_UNDEFINED;
+ cfi->drap_reg = CFI_UNDEFINED;
+ cfi->drap_offset = -1;
}
+
+static void init_insn_state(struct insn_state *state, struct section *sec)
+{
+ memset(state, 0, sizeof(*state));
+ init_cfi_state(&state->cfi);
+
+ /*
+ * We need the full vmlinux for noinstr validation, otherwise we can
+ * not correctly determine insn->call_dest->sec (external symbols do
+ * not have a section).
+ */
+ if (vmlinux && noinstr && sec)
+ state->noinstr = sec->noinstr;
+}
+
+static struct cfi_state *cfi_alloc(void)
+{
+ struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
+ if (!cfi) {
+ WARN("calloc failed");
+ exit(1);
+ }
+ nr_cfi++;
+ return cfi;
+}
+
+static int cfi_bits;
+static struct hlist_head *cfi_hash;
+
+static inline bool cficmp(struct cfi_state *cfi1, struct cfi_state *cfi2)
+{
+ return memcmp((void *)cfi1 + sizeof(cfi1->hash),
+ (void *)cfi2 + sizeof(cfi2->hash),
+ sizeof(struct cfi_state) - sizeof(struct hlist_node));
+}
+
+static inline u32 cfi_key(struct cfi_state *cfi)
+{
+ return jhash((void *)cfi + sizeof(cfi->hash),
+ sizeof(*cfi) - sizeof(cfi->hash), 0);
+}
+
+static struct cfi_state *cfi_hash_find_or_add(struct cfi_state *cfi)
+{
+ struct hlist_head *head = &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)];
+ struct cfi_state *obj;
+
+ hlist_for_each_entry(obj, head, hash) {
+ if (!cficmp(cfi, obj)) {
+ nr_cfi_cache++;
+ return obj;
+ }
+ }
+
+ obj = cfi_alloc();
+ *obj = *cfi;
+ hlist_add_head(&obj->hash, head);
+
+ return obj;
+}
+
+static void cfi_hash_add(struct cfi_state *cfi)
+{
+ struct hlist_head *head = &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)];
+
+ hlist_add_head(&cfi->hash, head);
+}
+
+static void *cfi_hash_alloc(void)
+{
+ cfi_bits = vmlinux ? ELF_HASH_BITS - 3 : 13;
+ cfi_hash = mmap(NULL, sizeof(struct hlist_head) << cfi_bits,
+ PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANON, -1, 0);
+ if (cfi_hash == (void *)-1L) {
+ WARN("mmap fail cfi_hash");
+ cfi_hash = NULL;
+ } else if (stats) {
+ printf("cfi_bits: %d\n", cfi_bits);
+ }
+
+ return cfi_hash;
+}
+
+static unsigned long nr_insns;
+static unsigned long nr_insns_visited;
/*
* Call the arch-specific instruction decoder for all the instructions and add
@@ -275,6 +367,11 @@
strncmp(sec->name, ".discard.", 9))
sec->text = true;
+ if (!strcmp(sec->name, ".noinstr.text") ||
+ !strcmp(sec->name, ".entry.text") ||
+ !strncmp(sec->name, ".text..__x86.", 13))
+ sec->noinstr = true;
+
for (offset = 0; offset < sec->len; offset += insn->len) {
insn = malloc(sizeof(*insn));
if (!insn) {
@@ -283,7 +380,7 @@
}
memset(insn, 0, sizeof(*insn));
INIT_LIST_HEAD(&insn->alts);
- clear_insn_state(&insn->state);
+ INIT_LIST_HEAD(&insn->stack_ops);
insn->sec = sec;
insn->offset = offset;
@@ -292,23 +389,17 @@
sec->len - offset,
&insn->len, &insn->type,
&insn->immediate,
- &insn->stack_op);
+ &insn->stack_ops);
if (ret)
goto err;
- if (!insn->type || insn->type > INSN_LAST) {
- WARN_FUNC("invalid instruction type %d",
- insn->sec, insn->offset, insn->type);
- ret = -1;
- goto err;
- }
-
- hash_add(file->insn_hash, &insn->hash, insn->offset);
+ hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset));
list_add_tail(&insn->list, &file->insn_list);
+ nr_insns++;
}
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC)
+ if (func->type != STT_FUNC || func->alias != func)
continue;
if (!find_insn(file, sec, func->offset)) {
@@ -317,11 +408,13 @@
return -1;
}
- func_for_each_insn(file, func, insn)
- if (!insn->func)
- insn->func = func;
+ sym_for_each_insn(file, func, insn)
+ insn->func = func;
}
}
+
+ if (stats)
+ printf("nr_insns: %lu\n", nr_insns);
return 0;
@@ -330,15 +423,27 @@
return ret;
}
+static struct instruction *find_last_insn(struct objtool_file *file,
+ struct section *sec)
+{
+ struct instruction *insn = NULL;
+ unsigned int offset;
+ unsigned int end = (sec->len > 10) ? sec->len - 10 : 0;
+
+ for (offset = sec->len - 1; offset >= end && !insn; offset--)
+ insn = find_insn(file, sec, offset);
+
+ return insn;
+}
+
/*
* Mark "ud2" instructions and manually annotated dead ends.
*/
static int add_dead_ends(struct objtool_file *file)
{
struct section *sec;
- struct rela *rela;
+ struct reloc *reloc;
struct instruction *insn;
- bool found;
/*
* By default, "ud2" is a dead end unless otherwise annotated, because
@@ -355,31 +460,24 @@
if (!sec)
goto reachable;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (insn)
insn = list_prev_entry(insn, list);
- else if (rela->addend == rela->sym->sec->len) {
- found = false;
- list_for_each_entry_reverse(insn, &file->insn_list, list) {
- if (insn->sec == rela->sym->sec) {
- found = true;
- break;
- }
- }
-
- if (!found) {
- WARN("can't find unreachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ else if (reloc->addend == reloc->sym->sec->len) {
+ insn = find_last_insn(file, reloc->sym->sec);
+ if (!insn) {
+ WARN("can't find unreachable insn at %s+0x%" PRIx64,
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
} else {
- WARN("can't find unreachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ WARN("can't find unreachable insn at %s+0x%" PRIx64,
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
@@ -397,35 +495,253 @@
if (!sec)
return 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (insn)
insn = list_prev_entry(insn, list);
- else if (rela->addend == rela->sym->sec->len) {
- found = false;
- list_for_each_entry_reverse(insn, &file->insn_list, list) {
- if (insn->sec == rela->sym->sec) {
- found = true;
- break;
- }
- }
-
- if (!found) {
- WARN("can't find reachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ else if (reloc->addend == reloc->sym->sec->len) {
+ insn = find_last_insn(file, reloc->sym->sec);
+ if (!insn) {
+ WARN("can't find reachable insn at %s+0x%" PRIx64,
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
} else {
- WARN("can't find reachable insn at %s+0x%x",
- rela->sym->sec->name, rela->addend);
+ WARN("can't find reachable insn at %s+0x%" PRIx64,
+ reloc->sym->sec->name, reloc->addend);
return -1;
}
insn->dead_end = false;
+ }
+
+ return 0;
+}
+
+static int create_static_call_sections(struct objtool_file *file)
+{
+ struct section *sec;
+ struct static_call_site *site;
+ struct instruction *insn;
+ struct symbol *key_sym;
+ char *key_name, *tmp;
+ int idx;
+
+ sec = find_section_by_name(file->elf, ".static_call_sites");
+ if (sec) {
+ INIT_LIST_HEAD(&file->static_call_list);
+ WARN("file already has .static_call_sites section, skipping");
+ return 0;
+ }
+
+ if (list_empty(&file->static_call_list))
+ return 0;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->static_call_list, call_node)
+ idx++;
+
+ sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE,
+ sizeof(struct static_call_site), idx);
+ if (!sec)
+ return -1;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->static_call_list, call_node) {
+
+ site = (struct static_call_site *)sec->data->d_buf + idx;
+ memset(site, 0, sizeof(struct static_call_site));
+
+ /* populate reloc for 'addr' */
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(struct static_call_site),
+ R_X86_64_PC32,
+ insn->sec, insn->offset))
+ return -1;
+
+ /* find key symbol */
+ key_name = strdup(insn->call_dest->name);
+ if (!key_name) {
+ perror("strdup");
+ return -1;
+ }
+ if (strncmp(key_name, STATIC_CALL_TRAMP_PREFIX_STR,
+ STATIC_CALL_TRAMP_PREFIX_LEN)) {
+ WARN("static_call: trampoline name malformed: %s", key_name);
+ free(key_name);
+ return -1;
+ }
+ tmp = key_name + STATIC_CALL_TRAMP_PREFIX_LEN - STATIC_CALL_KEY_PREFIX_LEN;
+ memcpy(tmp, STATIC_CALL_KEY_PREFIX_STR, STATIC_CALL_KEY_PREFIX_LEN);
+
+ key_sym = find_symbol_by_name(file->elf, tmp);
+ if (!key_sym) {
+ if (!module) {
+ WARN("static_call: can't find static_call_key symbol: %s", tmp);
+ free(key_name);
+ return -1;
+ }
+
+ /*
+ * For modules(), the key might not be exported, which
+ * means the module can make static calls but isn't
+ * allowed to change them.
+ *
+ * In that case we temporarily set the key to be the
+ * trampoline address. This is fixed up in
+ * static_call_add_module().
+ */
+ key_sym = insn->call_dest;
+ }
+ free(key_name);
+
+ /* populate reloc for 'key' */
+ if (elf_add_reloc(file->elf, sec,
+ idx * sizeof(struct static_call_site) + 4,
+ R_X86_64_PC32, key_sym,
+ is_sibling_call(insn) * STATIC_CALL_SITE_TAIL))
+ return -1;
+
+ idx++;
+ }
+
+ return 0;
+}
+
+static int create_retpoline_sites_sections(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct section *sec;
+ int idx;
+
+ sec = find_section_by_name(file->elf, ".retpoline_sites");
+ if (sec) {
+ WARN("file already has .retpoline_sites, skipping");
+ return 0;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->retpoline_call_list, call_node)
+ idx++;
+
+ if (!idx)
+ return 0;
+
+ sec = elf_create_section(file->elf, ".retpoline_sites", 0,
+ sizeof(int), idx);
+ if (!sec) {
+ WARN("elf_create_section: .retpoline_sites");
+ return -1;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
+
+ int *site = (int *)sec->data->d_buf + idx;
+ *site = 0;
+
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(int),
+ R_X86_64_PC32,
+ insn->sec, insn->offset)) {
+ WARN("elf_add_reloc_to_insn: .retpoline_sites");
+ return -1;
+ }
+
+ idx++;
+ }
+
+ return 0;
+}
+
+static int create_return_sites_sections(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct section *sec;
+ int idx;
+
+ sec = find_section_by_name(file->elf, ".return_sites");
+ if (sec) {
+ WARN("file already has .return_sites, skipping");
+ return 0;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->return_thunk_list, call_node)
+ idx++;
+
+ if (!idx)
+ return 0;
+
+ sec = elf_create_section(file->elf, ".return_sites", 0,
+ sizeof(int), idx);
+ if (!sec) {
+ WARN("elf_create_section: .return_sites");
+ return -1;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->return_thunk_list, call_node) {
+
+ int *site = (int *)sec->data->d_buf + idx;
+ *site = 0;
+
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(int),
+ R_X86_64_PC32,
+ insn->sec, insn->offset)) {
+ WARN("elf_add_reloc_to_insn: .return_sites");
+ return -1;
+ }
+
+ idx++;
+ }
+
+ return 0;
+}
+
+static int create_mcount_loc_sections(struct objtool_file *file)
+{
+ struct section *sec;
+ unsigned long *loc;
+ struct instruction *insn;
+ int idx;
+
+ sec = find_section_by_name(file->elf, "__mcount_loc");
+ if (sec) {
+ INIT_LIST_HEAD(&file->mcount_loc_list);
+ WARN("file already has __mcount_loc section, skipping");
+ return 0;
+ }
+
+ if (list_empty(&file->mcount_loc_list))
+ return 0;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node)
+ idx++;
+
+ sec = elf_create_section(file->elf, "__mcount_loc", 0, sizeof(unsigned long), idx);
+ if (!sec)
+ return -1;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) {
+
+ loc = (unsigned long *)sec->data->d_buf + idx;
+ memset(loc, 0, sizeof(unsigned long));
+
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned long),
+ R_X86_64_64,
+ insn->sec, insn->offset))
+ return -1;
+
+ idx++;
}
return 0;
@@ -439,18 +755,203 @@
struct instruction *insn;
struct section *sec;
struct symbol *func;
+ struct reloc *reloc;
- for_each_sec(file, sec) {
- list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC)
+ sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard");
+ if (!sec)
+ return;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ switch (reloc->sym->type) {
+ case STT_FUNC:
+ func = reloc->sym;
+ break;
+
+ case STT_SECTION:
+ func = find_func_by_offset(reloc->sym->sec, reloc->addend);
+ if (!func)
continue;
+ break;
- if (!ignore_func(file, func))
- continue;
-
- func_for_each_insn_all(file, func, insn)
- insn->ignore = true;
+ default:
+ WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type);
+ continue;
}
+
+ func_for_each_insn(file, func, insn)
+ insn->ignore = true;
+ }
+}
+
+/*
+ * This is a whitelist of functions that is allowed to be called with AC set.
+ * The list is meant to be minimal and only contains compiler instrumentation
+ * ABI and a few functions used to implement *_{to,from}_user() functions.
+ *
+ * These functions must not directly change AC, but may PUSHF/POPF.
+ */
+static const char *uaccess_safe_builtin[] = {
+ /* KASAN */
+ "kasan_report",
+ "kasan_check_range",
+ /* KASAN out-of-line */
+ "__asan_loadN_noabort",
+ "__asan_load1_noabort",
+ "__asan_load2_noabort",
+ "__asan_load4_noabort",
+ "__asan_load8_noabort",
+ "__asan_load16_noabort",
+ "__asan_storeN_noabort",
+ "__asan_store1_noabort",
+ "__asan_store2_noabort",
+ "__asan_store4_noabort",
+ "__asan_store8_noabort",
+ "__asan_store16_noabort",
+ "__kasan_check_read",
+ "__kasan_check_write",
+ /* KASAN in-line */
+ "__asan_report_load_n_noabort",
+ "__asan_report_load1_noabort",
+ "__asan_report_load2_noabort",
+ "__asan_report_load4_noabort",
+ "__asan_report_load8_noabort",
+ "__asan_report_load16_noabort",
+ "__asan_report_store_n_noabort",
+ "__asan_report_store1_noabort",
+ "__asan_report_store2_noabort",
+ "__asan_report_store4_noabort",
+ "__asan_report_store8_noabort",
+ "__asan_report_store16_noabort",
+ /* KCSAN */
+ "__kcsan_check_access",
+ "kcsan_found_watchpoint",
+ "kcsan_setup_watchpoint",
+ "kcsan_check_scoped_accesses",
+ "kcsan_disable_current",
+ "kcsan_enable_current_nowarn",
+ /* KCSAN/TSAN */
+ "__tsan_func_entry",
+ "__tsan_func_exit",
+ "__tsan_read_range",
+ "__tsan_write_range",
+ "__tsan_read1",
+ "__tsan_read2",
+ "__tsan_read4",
+ "__tsan_read8",
+ "__tsan_read16",
+ "__tsan_write1",
+ "__tsan_write2",
+ "__tsan_write4",
+ "__tsan_write8",
+ "__tsan_write16",
+ "__tsan_read_write1",
+ "__tsan_read_write2",
+ "__tsan_read_write4",
+ "__tsan_read_write8",
+ "__tsan_read_write16",
+ "__tsan_volatile_read1",
+ "__tsan_volatile_read2",
+ "__tsan_volatile_read4",
+ "__tsan_volatile_read8",
+ "__tsan_volatile_read16",
+ "__tsan_volatile_write1",
+ "__tsan_volatile_write2",
+ "__tsan_volatile_write4",
+ "__tsan_volatile_write8",
+ "__tsan_volatile_write16",
+ "__tsan_atomic8_load",
+ "__tsan_atomic16_load",
+ "__tsan_atomic32_load",
+ "__tsan_atomic64_load",
+ "__tsan_atomic8_store",
+ "__tsan_atomic16_store",
+ "__tsan_atomic32_store",
+ "__tsan_atomic64_store",
+ "__tsan_atomic8_exchange",
+ "__tsan_atomic16_exchange",
+ "__tsan_atomic32_exchange",
+ "__tsan_atomic64_exchange",
+ "__tsan_atomic8_fetch_add",
+ "__tsan_atomic16_fetch_add",
+ "__tsan_atomic32_fetch_add",
+ "__tsan_atomic64_fetch_add",
+ "__tsan_atomic8_fetch_sub",
+ "__tsan_atomic16_fetch_sub",
+ "__tsan_atomic32_fetch_sub",
+ "__tsan_atomic64_fetch_sub",
+ "__tsan_atomic8_fetch_and",
+ "__tsan_atomic16_fetch_and",
+ "__tsan_atomic32_fetch_and",
+ "__tsan_atomic64_fetch_and",
+ "__tsan_atomic8_fetch_or",
+ "__tsan_atomic16_fetch_or",
+ "__tsan_atomic32_fetch_or",
+ "__tsan_atomic64_fetch_or",
+ "__tsan_atomic8_fetch_xor",
+ "__tsan_atomic16_fetch_xor",
+ "__tsan_atomic32_fetch_xor",
+ "__tsan_atomic64_fetch_xor",
+ "__tsan_atomic8_fetch_nand",
+ "__tsan_atomic16_fetch_nand",
+ "__tsan_atomic32_fetch_nand",
+ "__tsan_atomic64_fetch_nand",
+ "__tsan_atomic8_compare_exchange_strong",
+ "__tsan_atomic16_compare_exchange_strong",
+ "__tsan_atomic32_compare_exchange_strong",
+ "__tsan_atomic64_compare_exchange_strong",
+ "__tsan_atomic8_compare_exchange_weak",
+ "__tsan_atomic16_compare_exchange_weak",
+ "__tsan_atomic32_compare_exchange_weak",
+ "__tsan_atomic64_compare_exchange_weak",
+ "__tsan_atomic8_compare_exchange_val",
+ "__tsan_atomic16_compare_exchange_val",
+ "__tsan_atomic32_compare_exchange_val",
+ "__tsan_atomic64_compare_exchange_val",
+ "__tsan_atomic_thread_fence",
+ "__tsan_atomic_signal_fence",
+ "__tsan_unaligned_read16",
+ "__tsan_unaligned_write16",
+ /* KCOV */
+ "write_comp_data",
+ "check_kcov_mode",
+ "__sanitizer_cov_trace_pc",
+ "__sanitizer_cov_trace_const_cmp1",
+ "__sanitizer_cov_trace_const_cmp2",
+ "__sanitizer_cov_trace_const_cmp4",
+ "__sanitizer_cov_trace_const_cmp8",
+ "__sanitizer_cov_trace_cmp1",
+ "__sanitizer_cov_trace_cmp2",
+ "__sanitizer_cov_trace_cmp4",
+ "__sanitizer_cov_trace_cmp8",
+ "__sanitizer_cov_trace_switch",
+ /* UBSAN */
+ "ubsan_type_mismatch_common",
+ "__ubsan_handle_type_mismatch",
+ "__ubsan_handle_type_mismatch_v1",
+ "__ubsan_handle_shift_out_of_bounds",
+ /* misc */
+ "csum_partial_copy_generic",
+ "copy_mc_fragile",
+ "copy_mc_fragile_handle_tail",
+ "copy_mc_enhanced_fast_string",
+ "ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */
+ NULL
+};
+
+static void add_uaccess_safe(struct objtool_file *file)
+{
+ struct symbol *func;
+ const char **name;
+
+ if (!uaccess)
+ return;
+
+ for (name = uaccess_safe_builtin; *name; name++) {
+ func = find_symbol_by_name(file->elf, *name);
+ if (!func)
+ continue;
+
+ func->uaccess_safe = true;
}
}
@@ -460,25 +961,25 @@
* But it at least allows objtool to understand the control flow *around* the
* retpoline.
*/
-static int add_nospec_ignores(struct objtool_file *file)
+static int add_ignore_alternatives(struct objtool_file *file)
{
struct section *sec;
- struct rela *rela;
+ struct reloc *reloc;
struct instruction *insn;
- sec = find_section_by_name(file->elf, ".rela.discard.nospec");
+ sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
if (!sec)
return 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!insn) {
- WARN("bad .discard.nospec entry");
+ WARN("bad .discard.ignore_alts entry");
return -1;
}
@@ -489,50 +990,266 @@
}
/*
+ * Symbols that replace INSN_CALL_DYNAMIC, every (tail) call to such a symbol
+ * will be added to the .retpoline_sites section.
+ */
+__weak bool arch_is_retpoline(struct symbol *sym)
+{
+ return false;
+}
+
+/*
+ * Symbols that replace INSN_RETURN, every (tail) call to such a symbol
+ * will be added to the .return_sites section.
+ */
+__weak bool arch_is_rethunk(struct symbol *sym)
+{
+ return false;
+}
+
+/*
+ * Symbols that are embedded inside other instructions, because sometimes crazy
+ * code exists. These are mostly ignored for validation purposes.
+ */
+__weak bool arch_is_embedded_insn(struct symbol *sym)
+{
+ return false;
+}
+
+#define NEGATIVE_RELOC ((void *)-1L)
+
+static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn)
+{
+ if (insn->reloc == NEGATIVE_RELOC)
+ return NULL;
+
+ if (!insn->reloc) {
+ insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!insn->reloc) {
+ insn->reloc = NEGATIVE_RELOC;
+ return NULL;
+ }
+ }
+
+ return insn->reloc;
+}
+
+static void remove_insn_ops(struct instruction *insn)
+{
+ struct stack_op *op, *tmp;
+
+ list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
+ list_del(&op->list);
+ free(op);
+ }
+}
+
+static void annotate_call_site(struct objtool_file *file,
+ struct instruction *insn, bool sibling)
+{
+ struct reloc *reloc = insn_reloc(file, insn);
+ struct symbol *sym = insn->call_dest;
+
+ if (!sym)
+ sym = reloc->sym;
+
+ /*
+ * Alternative replacement code is just template code which is
+ * sometimes copied to the original instruction. For now, don't
+ * annotate it. (In the future we might consider annotating the
+ * original instruction if/when it ever makes sense to do so.)
+ */
+ if (!strcmp(insn->sec->name, ".altinstr_replacement"))
+ return;
+
+ if (sym->static_call_tramp) {
+ list_add_tail(&insn->call_node, &file->static_call_list);
+ return;
+ }
+
+ if (sym->retpoline_thunk) {
+ list_add_tail(&insn->call_node, &file->retpoline_call_list);
+ return;
+ }
+
+ /*
+ * Many compilers cannot disable KCOV with a function attribute
+ * so they need a little help, NOP out any KCOV calls from noinstr
+ * text.
+ */
+ if (insn->sec->noinstr && sym->kcov) {
+ if (reloc) {
+ reloc->type = R_NONE;
+ elf_write_reloc(file->elf, reloc);
+ }
+
+ elf_write_insn(file->elf, insn->sec,
+ insn->offset, insn->len,
+ sibling ? arch_ret_insn(insn->len)
+ : arch_nop_insn(insn->len));
+
+ insn->type = sibling ? INSN_RETURN : INSN_NOP;
+
+ if (sibling) {
+ /*
+ * We've replaced the tail-call JMP insn by two new
+ * insn: RET; INT3, except we only have a single struct
+ * insn here. Mark it retpoline_safe to avoid the SLS
+ * warning, instead of adding another insn.
+ */
+ insn->retpoline_safe = true;
+ }
+
+ return;
+ }
+}
+
+static void add_call_dest(struct objtool_file *file, struct instruction *insn,
+ struct symbol *dest, bool sibling)
+{
+ insn->call_dest = dest;
+ if (!dest)
+ return;
+
+ /*
+ * Whatever stack impact regular CALLs have, should be undone
+ * by the RETURN of the called function.
+ *
+ * Annotated intra-function calls retain the stack_ops but
+ * are converted to JUMP, see read_intra_function_calls().
+ */
+ remove_insn_ops(insn);
+
+ annotate_call_site(file, insn, sibling);
+}
+
+static void add_retpoline_call(struct objtool_file *file, struct instruction *insn)
+{
+ /*
+ * Retpoline calls/jumps are really dynamic calls/jumps in disguise,
+ * so convert them accordingly.
+ */
+ switch (insn->type) {
+ case INSN_CALL:
+ insn->type = INSN_CALL_DYNAMIC;
+ break;
+ case INSN_JUMP_UNCONDITIONAL:
+ insn->type = INSN_JUMP_DYNAMIC;
+ break;
+ case INSN_JUMP_CONDITIONAL:
+ insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
+ break;
+ default:
+ return;
+ }
+
+ insn->retpoline_safe = true;
+
+ /*
+ * Whatever stack impact regular CALLs have, should be undone
+ * by the RETURN of the called function.
+ *
+ * Annotated intra-function calls retain the stack_ops but
+ * are converted to JUMP, see read_intra_function_calls().
+ */
+ remove_insn_ops(insn);
+
+ annotate_call_site(file, insn, false);
+}
+
+static void add_return_call(struct objtool_file *file, struct instruction *insn, bool add)
+{
+ /*
+ * Return thunk tail calls are really just returns in disguise,
+ * so convert them accordingly.
+ */
+ insn->type = INSN_RETURN;
+ insn->retpoline_safe = true;
+
+ /* Skip the non-text sections, specially .discard ones */
+ if (add && insn->sec->text)
+ list_add_tail(&insn->call_node, &file->return_thunk_list);
+}
+
+/*
+ * CONFIG_CFI_CLANG: Check if the section is a CFI jump table or a
+ * compiler-generated CFI handler.
+ */
+static bool is_cfi_section(struct section *sec)
+{
+ return (sec->name &&
+ (!strncmp(sec->name, ".text..L.cfi.jumptable", 22) ||
+ !strcmp(sec->name, ".text.__cfi_check")));
+}
+
+/*
+ * CONFIG_CFI_CLANG: Ignore CFI jump tables.
+ */
+static void add_cfi_jumptables(struct objtool_file *file)
+{
+ struct section *sec;
+ struct symbol *func;
+ struct instruction *insn;
+
+ for_each_sec(file, sec) {
+ if (!is_cfi_section(sec))
+ continue;
+
+ list_for_each_entry(func, &sec->symbol_list, list) {
+ sym_for_each_insn(file, func, insn)
+ insn->ignore = true;
+ }
+ }
+}
+
+/*
* Find the destination instructions for all jumps.
*/
static int add_jump_destinations(struct objtool_file *file)
{
struct instruction *insn;
- struct rela *rela;
+ struct reloc *reloc;
struct section *dest_sec;
unsigned long dest_off;
for_each_insn(file, insn) {
- if (insn->type != INSN_JUMP_CONDITIONAL &&
- insn->type != INSN_JUMP_UNCONDITIONAL)
+ if (!is_static_jump(insn))
continue;
- if (insn->offset == FAKE_JUMP_OFFSET)
- continue;
-
- rela = find_rela_by_dest_range(insn->sec, insn->offset,
- insn->len);
- if (!rela) {
+ reloc = insn_reloc(file, insn);
+ if (!reloc) {
dest_sec = insn->sec;
- dest_off = insn->offset + insn->len + insn->immediate;
- } else if (rela->sym->type == STT_SECTION) {
- dest_sec = rela->sym->sec;
- dest_off = rela->addend + 4;
- } else if (rela->sym->sec->idx) {
- dest_sec = rela->sym->sec;
- dest_off = rela->sym->sym.st_value + rela->addend + 4;
- } else if (strstr(rela->sym->name, "_indirect_thunk_")) {
- /*
- * Retpoline jumps are really dynamic jumps in
- * disguise, so convert them accordingly.
- */
- insn->type = INSN_JUMP_DYNAMIC;
- insn->retpoline_safe = true;
+ dest_off = arch_jump_destination(insn);
+ } else if (reloc->sym->type == STT_SECTION) {
+ dest_sec = reloc->sym->sec;
+ dest_off = arch_dest_reloc_offset(reloc->addend);
+ } else if (reloc->sym->retpoline_thunk) {
+ add_retpoline_call(file, insn);
continue;
+ } else if (reloc->sym->return_thunk) {
+ add_return_call(file, insn, true);
+ continue;
+ } else if (insn->func) {
+ /* internal or external sibling call (with reloc) */
+ add_call_dest(file, insn, reloc->sym, true);
+ continue;
+ } else if (reloc->sym->sec->idx) {
+ dest_sec = reloc->sym->sec;
+ dest_off = reloc->sym->sym.st_value +
+ arch_dest_reloc_offset(reloc->addend);
} else {
- /* sibling call */
- insn->jump_dest = 0;
+ /* non-func asm code jumping to another file */
continue;
}
insn->jump_dest = find_insn(file, dest_sec, dest_off);
+
+ if (!insn->jump_dest && dest_sec->len == dest_off)
+ insn->jump_dest = find_last_insn(file, dest_sec);
+
if (!insn->jump_dest) {
+ struct symbol *sym = find_symbol_by_offset(dest_sec, dest_off);
/*
* This is a special case where an alt instruction
@@ -542,6 +1259,22 @@
if (!strcmp(insn->sec->name, ".altinstr_replacement"))
continue;
+ if (is_cfi_section(insn->sec))
+ continue;
+
+ /*
+ * This is a special case for retbleed_untrain_ret().
+ * It jumps to __x86_return_thunk(), but objtool
+ * can't find the thunk's starting RET
+ * instruction, because the RET is also in the
+ * middle of another instruction. Objtool only
+ * knows about the outer instruction.
+ */
+ if (sym && sym->embedded_insn) {
+ add_return_call(file, insn, false);
+ continue;
+ }
+
WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
insn->sec, insn->offset, dest_sec->name,
dest_off);
@@ -549,29 +1282,51 @@
}
/*
- * For GCC 8+, create parent/child links for any cold
- * subfunctions. This is _mostly_ redundant with a similar
- * initialization in read_symbols().
- *
- * If a function has aliases, we want the *first* such function
- * in the symbol table to be the subfunction's parent. In that
- * case we overwrite the initialization done in read_symbols().
- *
- * However this code can't completely replace the
- * read_symbols() code because this doesn't detect the case
- * where the parent function's only reference to a subfunction
- * is through a switch table.
+ * Cross-function jump.
*/
if (insn->func && insn->jump_dest->func &&
- insn->func != insn->jump_dest->func &&
- !strstr(insn->func->name, ".cold.") &&
- strstr(insn->jump_dest->func->name, ".cold.")) {
- insn->func->cfunc = insn->jump_dest->func;
- insn->jump_dest->func->pfunc = insn->func;
+ insn->func != insn->jump_dest->func) {
+
+ /*
+ * For GCC 8+, create parent/child links for any cold
+ * subfunctions. This is _mostly_ redundant with a
+ * similar initialization in read_symbols().
+ *
+ * If a function has aliases, we want the *first* such
+ * function in the symbol table to be the subfunction's
+ * parent. In that case we overwrite the
+ * initialization done in read_symbols().
+ *
+ * However this code can't completely replace the
+ * read_symbols() code because this doesn't detect the
+ * case where the parent function's only reference to a
+ * subfunction is through a jump table.
+ */
+ if (!strstr(insn->func->name, ".cold") &&
+ strstr(insn->jump_dest->func->name, ".cold")) {
+ insn->func->cfunc = insn->jump_dest->func;
+ insn->jump_dest->func->pfunc = insn->func;
+
+ } else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
+ insn->jump_dest->offset == insn->jump_dest->func->offset) {
+ /* internal sibling call (without reloc) */
+ add_call_dest(file, insn, insn->jump_dest->func, true);
+ }
}
}
return 0;
+}
+
+static struct symbol *find_call_destination(struct section *sec, unsigned long offset)
+{
+ struct symbol *call_dest;
+
+ call_dest = find_func_by_offset(sec, offset);
+ if (!call_dest)
+ call_dest = find_symbol_by_offset(sec, offset);
+
+ return call_dest;
}
/*
@@ -581,72 +1336,85 @@
{
struct instruction *insn;
unsigned long dest_off;
- struct rela *rela;
+ struct symbol *dest;
+ struct reloc *reloc;
for_each_insn(file, insn) {
if (insn->type != INSN_CALL)
continue;
- rela = find_rela_by_dest_range(insn->sec, insn->offset,
- insn->len);
- if (!rela) {
- dest_off = insn->offset + insn->len + insn->immediate;
- insn->call_dest = find_symbol_by_offset(insn->sec,
- dest_off);
+ reloc = insn_reloc(file, insn);
+ if (!reloc) {
+ dest_off = arch_jump_destination(insn);
+ dest = find_call_destination(insn->sec, dest_off);
- if (!insn->call_dest && !insn->ignore) {
- WARN_FUNC("unsupported intra-function call",
+ add_call_dest(file, insn, dest, false);
+
+ if (insn->ignore)
+ continue;
+
+ if (!insn->call_dest) {
+ WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset);
+ return -1;
+ }
+
+ if (insn->func && insn->call_dest->type != STT_FUNC) {
+ WARN_FUNC("unsupported call to non-function",
insn->sec, insn->offset);
- if (retpoline)
- WARN("If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.");
return -1;
}
- } else if (rela->sym->type == STT_SECTION) {
- insn->call_dest = find_symbol_by_offset(rela->sym->sec,
- rela->addend+4);
- if (!insn->call_dest ||
- insn->call_dest->type != STT_FUNC) {
- WARN_FUNC("can't find call dest symbol at %s+0x%x",
+ } else if (reloc->sym->type == STT_SECTION) {
+ dest_off = arch_dest_reloc_offset(reloc->addend);
+ dest = find_call_destination(reloc->sym->sec, dest_off);
+ if (!dest) {
+ if (is_cfi_section(reloc->sym->sec))
+ continue;
+
+ WARN_FUNC("can't find call dest symbol at %s+0x%lx",
insn->sec, insn->offset,
- rela->sym->sec->name,
- rela->addend + 4);
+ reloc->sym->sec->name,
+ dest_off);
return -1;
}
+
+ add_call_dest(file, insn, dest, false);
+
+ } else if (reloc->sym->retpoline_thunk) {
+ add_retpoline_call(file, insn);
+
} else
- insn->call_dest = rela->sym;
+ add_call_dest(file, insn, reloc->sym, false);
}
return 0;
}
/*
- * The .alternatives section requires some extra special care, over and above
- * what other special sections require:
- *
- * 1. Because alternatives are patched in-place, we need to insert a fake jump
- * instruction at the end so that validate_branch() skips all the original
- * replaced instructions when validating the new instruction path.
- *
- * 2. An added wrinkle is that the new instruction length might be zero. In
- * that case the old instructions are replaced with noops. We simulate that
- * by creating a fake jump as the only new instruction.
- *
- * 3. In some cases, the alternative section includes an instruction which
- * conditionally jumps to the _end_ of the entry. We have to modify these
- * jumps' destinations to point back to .text rather than the end of the
- * entry in .altinstr_replacement.
- *
- * 4. It has been requested that we don't validate the !POPCNT feature path
- * which is a "very very small percentage of machines".
+ * The .alternatives section requires some extra special care over and above
+ * other special sections because alternatives are patched in place.
*/
static int handle_group_alt(struct objtool_file *file,
struct special_alt *special_alt,
struct instruction *orig_insn,
struct instruction **new_insn)
{
- struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
+ struct instruction *last_orig_insn, *last_new_insn = NULL, *insn, *nop = NULL;
+ struct alt_group *orig_alt_group, *new_alt_group;
unsigned long dest_off;
+
+
+ orig_alt_group = malloc(sizeof(*orig_alt_group));
+ if (!orig_alt_group) {
+ WARN("malloc failed");
+ return -1;
+ }
+ orig_alt_group->cfi = calloc(special_alt->orig_len,
+ sizeof(struct cfi_state *));
+ if (!orig_alt_group->cfi) {
+ WARN("calloc failed");
+ return -1;
+ }
last_orig_insn = NULL;
insn = orig_insn;
@@ -654,67 +1422,90 @@
if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
break;
- if (special_alt->skip_orig)
- insn->type = INSN_NOP;
-
- insn->alt_group = true;
+ insn->alt_group = orig_alt_group;
last_orig_insn = insn;
}
+ orig_alt_group->orig_group = NULL;
+ orig_alt_group->first_insn = orig_insn;
+ orig_alt_group->last_insn = last_orig_insn;
- if (next_insn_same_sec(file, last_orig_insn)) {
- fake_jump = malloc(sizeof(*fake_jump));
- if (!fake_jump) {
+
+ new_alt_group = malloc(sizeof(*new_alt_group));
+ if (!new_alt_group) {
+ WARN("malloc failed");
+ return -1;
+ }
+
+ if (special_alt->new_len < special_alt->orig_len) {
+ /*
+ * Insert a fake nop at the end to make the replacement
+ * alt_group the same size as the original. This is needed to
+ * allow propagate_alt_cfi() to do its magic. When the last
+ * instruction affects the stack, the instruction after it (the
+ * nop) will propagate the new state to the shared CFI array.
+ */
+ nop = malloc(sizeof(*nop));
+ if (!nop) {
WARN("malloc failed");
return -1;
}
- memset(fake_jump, 0, sizeof(*fake_jump));
- INIT_LIST_HEAD(&fake_jump->alts);
- clear_insn_state(&fake_jump->state);
+ memset(nop, 0, sizeof(*nop));
+ INIT_LIST_HEAD(&nop->alts);
+ INIT_LIST_HEAD(&nop->stack_ops);
- fake_jump->sec = special_alt->new_sec;
- fake_jump->offset = FAKE_JUMP_OFFSET;
- fake_jump->type = INSN_JUMP_UNCONDITIONAL;
- fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
- fake_jump->func = orig_insn->func;
+ nop->sec = special_alt->new_sec;
+ nop->offset = special_alt->new_off + special_alt->new_len;
+ nop->len = special_alt->orig_len - special_alt->new_len;
+ nop->type = INSN_NOP;
+ nop->func = orig_insn->func;
+ nop->alt_group = new_alt_group;
+ nop->ignore = orig_insn->ignore_alts;
}
if (!special_alt->new_len) {
- if (!fake_jump) {
- WARN("%s: empty alternative at end of section",
- special_alt->orig_sec->name);
- return -1;
- }
-
- *new_insn = fake_jump;
- return 0;
+ *new_insn = nop;
+ goto end;
}
- last_new_insn = NULL;
insn = *new_insn;
sec_for_each_insn_from(file, insn) {
+ struct reloc *alt_reloc;
+
if (insn->offset >= special_alt->new_off + special_alt->new_len)
break;
last_new_insn = insn;
insn->ignore = orig_insn->ignore_alts;
+ insn->func = orig_insn->func;
+ insn->alt_group = new_alt_group;
- if (insn->type != INSN_JUMP_CONDITIONAL &&
- insn->type != INSN_JUMP_UNCONDITIONAL)
+ /*
+ * Since alternative replacement code is copy/pasted by the
+ * kernel after applying relocations, generally such code can't
+ * have relative-address relocation references to outside the
+ * .altinstr_replacement section, unless the arch's
+ * alternatives code can adjust the relative offsets
+ * accordingly.
+ */
+ alt_reloc = insn_reloc(file, insn);
+ if (alt_reloc &&
+ !arch_support_alt_relocation(special_alt, insn, alt_reloc)) {
+
+ WARN_FUNC("unsupported relocation in alternatives section",
+ insn->sec, insn->offset);
+ return -1;
+ }
+
+ if (!is_static_jump(insn))
continue;
if (!insn->immediate)
continue;
- dest_off = insn->offset + insn->len + insn->immediate;
- if (dest_off == special_alt->new_off + special_alt->new_len) {
- if (!fake_jump) {
- WARN("%s: alternative jump to end of section",
- special_alt->orig_sec->name);
- return -1;
- }
- insn->jump_dest = fake_jump;
- }
+ dest_off = arch_jump_destination(insn);
+ if (dest_off == special_alt->new_off + special_alt->new_len)
+ insn->jump_dest = next_insn_same_sec(file, last_orig_insn);
if (!insn->jump_dest) {
WARN_FUNC("can't find alternative jump destination",
@@ -729,9 +1520,13 @@
return -1;
}
- if (fake_jump)
- list_add(&fake_jump->list, &last_new_insn->list);
-
+ if (nop)
+ list_add(&nop->list, &last_new_insn->list);
+end:
+ new_alt_group->orig_group = orig_alt_group;
+ new_alt_group->first_insn = *new_insn;
+ new_alt_group->last_insn = nop ? : last_new_insn;
+ new_alt_group->cfi = orig_alt_group->cfi;
return 0;
}
@@ -826,6 +1621,8 @@
}
alt->insn = new_insn;
+ alt->skip_orig = special_alt->skip_orig;
+ orig_insn->ignore_alts |= special_alt->skip_alt;
list_add_tail(&alt->list, &orig_insn->alts);
list_del(&special_alt->list);
@@ -836,34 +1633,40 @@
return ret;
}
-static int add_switch_table(struct objtool_file *file, struct instruction *insn,
- struct rela *table, struct rela *next_table)
+static int add_jump_table(struct objtool_file *file, struct instruction *insn,
+ struct reloc *table)
{
- struct rela *rela = table;
- struct instruction *alt_insn;
+ struct reloc *reloc = table;
+ struct instruction *dest_insn;
struct alternative *alt;
struct symbol *pfunc = insn->func->pfunc;
unsigned int prev_offset = 0;
- list_for_each_entry_from(rela, &table->rela_sec->rela_list, list) {
- if (rela == next_table)
+ /*
+ * Each @reloc is a switch table relocation which points to the target
+ * instruction.
+ */
+ list_for_each_entry_from(reloc, &table->sec->reloc_list, list) {
+
+ /* Check for the end of the table: */
+ if (reloc != table && reloc->jump_table_start)
break;
- /* Make sure the switch table entries are consecutive: */
- if (prev_offset && rela->offset != prev_offset + 8)
+ /* Make sure the table entries are consecutive: */
+ if (prev_offset && reloc->offset != prev_offset + 8)
break;
/* Detect function pointers from contiguous objects: */
- if (rela->sym->sec == pfunc->sec &&
- rela->addend == pfunc->offset)
+ if (reloc->sym->sec == pfunc->sec &&
+ reloc->addend == pfunc->offset)
break;
- alt_insn = find_insn(file, rela->sym->sec, rela->addend);
- if (!alt_insn)
+ dest_insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!dest_insn)
break;
- /* Make sure the jmp dest is in the function or subfunction: */
- if (alt_insn->func->pfunc != pfunc)
+ /* Make sure the destination is in the same function: */
+ if (!dest_insn->func || dest_insn->func->pfunc != pfunc)
break;
alt = malloc(sizeof(*alt));
@@ -872,9 +1675,9 @@
return -1;
}
- alt->insn = alt_insn;
+ alt->insn = dest_insn;
list_add_tail(&alt->list, &insn->alts);
- prev_offset = rela->offset;
+ prev_offset = reloc->offset;
}
if (!prev_offset) {
@@ -887,56 +1690,15 @@
}
/*
- * find_switch_table() - Given a dynamic jump, find the switch jump table in
- * .rodata associated with it.
- *
- * There are 3 basic patterns:
- *
- * 1. jmpq *[rodata addr](,%reg,8)
- *
- * This is the most common case by far. It jumps to an address in a simple
- * jump table which is stored in .rodata.
- *
- * 2. jmpq *[rodata addr](%rip)
- *
- * This is caused by a rare GCC quirk, currently only seen in three driver
- * functions in the kernel, only with certain obscure non-distro configs.
- *
- * As part of an optimization, GCC makes a copy of an existing switch jump
- * table, modifies it, and then hard-codes the jump (albeit with an indirect
- * jump) to use a single entry in the table. The rest of the jump table and
- * some of its jump targets remain as dead code.
- *
- * In such a case we can just crudely ignore all unreachable instruction
- * warnings for the entire object file. Ideally we would just ignore them
- * for the function, but that would require redesigning the code quite a
- * bit. And honestly that's just not worth doing: unreachable instruction
- * warnings are of questionable value anyway, and this is such a rare issue.
- *
- * 3. mov [rodata addr],%reg1
- * ... some instructions ...
- * jmpq *(%reg1,%reg2,8)
- *
- * This is a fairly uncommon pattern which is new for GCC 6. As of this
- * writing, there are 11 occurrences of it in the allmodconfig kernel.
- *
- * As of GCC 7 there are quite a few more of these and the 'in between' code
- * is significant. Esp. with KASAN enabled some of the code between the mov
- * and jmpq uses .rodata itself, which can confuse things.
- *
- * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
- * ensure the same register is used in the mov and jump instructions.
- *
- * NOTE: RETPOLINE made it harder still to decode dynamic jumps.
+ * find_jump_table() - Given a dynamic jump, find the switch jump table
+ * associated with it.
*/
-static struct rela *find_switch_table(struct objtool_file *file,
+static struct reloc *find_jump_table(struct objtool_file *file,
struct symbol *func,
struct instruction *insn)
{
- struct rela *text_rela, *rodata_rela;
- struct instruction *orig_insn = insn;
- struct section *rodata_sec;
- unsigned long table_offset;
+ struct reloc *table_reloc;
+ struct instruction *dest_insn, *orig_insn = insn;
/*
* Backward search using the @first_jump_src links, these help avoid
@@ -944,8 +1706,8 @@
* it.
*/
for (;
- &insn->list != &file->insn_list && insn->func && insn->func->pfunc == func;
- insn = insn->first_jump_src ?: list_prev_entry(insn, list)) {
+ insn && insn->func && insn->func->pfunc == func;
+ insn = insn->first_jump_src ?: prev_insn_same_sym(file, insn)) {
if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC)
break;
@@ -957,58 +1719,36 @@
insn->jump_dest->offset > orig_insn->offset))
break;
- /* look for a relocation which references .rodata */
- text_rela = find_rela_by_dest_range(insn->sec, insn->offset,
- insn->len);
- if (!text_rela || text_rela->sym->type != STT_SECTION ||
- !text_rela->sym->sec->rodata)
+ table_reloc = arch_find_switch_table(file, insn);
+ if (!table_reloc)
+ continue;
+ dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend);
+ if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func)
continue;
- table_offset = text_rela->addend;
- rodata_sec = text_rela->sym->sec;
-
- if (text_rela->type == R_X86_64_PC32)
- table_offset += 4;
-
- /*
- * Make sure the .rodata address isn't associated with a
- * symbol. gcc jump tables are anonymous data.
- */
- if (find_symbol_containing(rodata_sec, table_offset))
- continue;
-
- rodata_rela = find_rela_by_dest(rodata_sec, table_offset);
- if (rodata_rela) {
- /*
- * Use of RIP-relative switch jumps is quite rare, and
- * indicates a rare GCC quirk/bug which can leave dead
- * code behind.
- */
- if (text_rela->type == R_X86_64_PC32)
- file->ignore_unreachables = true;
-
- return rodata_rela;
- }
+ return table_reloc;
}
return NULL;
}
-
-static int add_func_switch_tables(struct objtool_file *file,
- struct symbol *func)
+/*
+ * First pass: Mark the head of each jump table so that in the next pass,
+ * we know when a given jump table ends and the next one starts.
+ */
+static void mark_func_jump_tables(struct objtool_file *file,
+ struct symbol *func)
{
- struct instruction *insn, *last = NULL, *prev_jump = NULL;
- struct rela *rela, *prev_rela = NULL;
- int ret;
+ struct instruction *insn, *last = NULL;
+ struct reloc *reloc;
- func_for_each_insn_all(file, func, insn) {
+ func_for_each_insn(file, func, insn) {
if (!last)
last = insn;
/*
* Store back-pointers for unconditional forward jumps such
- * that find_switch_table() can back-track using those and
+ * that find_jump_table() can back-track using those and
* avoid some potentially confusing code.
*/
if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest &&
@@ -1023,27 +1763,25 @@
if (insn->type != INSN_JUMP_DYNAMIC)
continue;
- rela = find_switch_table(file, func, insn);
- if (!rela)
+ reloc = find_jump_table(file, func, insn);
+ if (reloc) {
+ reloc->jump_table_start = true;
+ insn->jump_table = reloc;
+ }
+ }
+}
+
+static int add_func_jump_tables(struct objtool_file *file,
+ struct symbol *func)
+{
+ struct instruction *insn;
+ int ret;
+
+ func_for_each_insn(file, func, insn) {
+ if (!insn->jump_table)
continue;
- /*
- * We found a switch table, but we don't know yet how big it
- * is. Don't add it until we reach the end of the function or
- * the beginning of another switch table in the same function.
- */
- if (prev_jump) {
- ret = add_switch_table(file, prev_jump, prev_rela, rela);
- if (ret)
- return ret;
- }
-
- prev_jump = insn;
- prev_rela = rela;
- }
-
- if (prev_jump) {
- ret = add_switch_table(file, prev_jump, prev_rela, NULL);
+ ret = add_jump_table(file, insn, insn->jump_table);
if (ret)
return ret;
}
@@ -1056,7 +1794,7 @@
* section which contains a list of addresses within the function to jump to.
* This finds these jump tables and adds them to the insn->alts lists.
*/
-static int add_switch_table_alts(struct objtool_file *file)
+static int add_jump_table_alts(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;
@@ -1070,7 +1808,8 @@
if (func->type != STT_FUNC)
continue;
- ret = add_func_switch_tables(file, func);
+ mark_func_jump_tables(file, func);
+ ret = add_func_jump_tables(file, func);
if (ret)
return ret;
}
@@ -1079,21 +1818,29 @@
return 0;
}
+static void set_func_state(struct cfi_state *state)
+{
+ state->cfa = initial_func_cfi.cfa;
+ memcpy(&state->regs, &initial_func_cfi.regs,
+ CFI_NUM_REGS * sizeof(struct cfi_reg));
+ state->stack_size = initial_func_cfi.cfa.offset;
+}
+
static int read_unwind_hints(struct objtool_file *file)
{
- struct section *sec, *relasec;
- struct rela *rela;
+ struct cfi_state cfi = init_cfi;
+ struct section *sec, *relocsec;
struct unwind_hint *hint;
struct instruction *insn;
- struct cfi_reg *cfa;
+ struct reloc *reloc;
int i;
sec = find_section_by_name(file->elf, ".discard.unwind_hints");
if (!sec)
return 0;
- relasec = sec->rela;
- if (!relasec) {
+ relocsec = sec->reloc;
+ if (!relocsec) {
WARN("missing .rela.discard.unwind_hints section");
return -1;
}
@@ -1108,66 +1855,63 @@
for (i = 0; i < sec->len / sizeof(struct unwind_hint); i++) {
hint = (struct unwind_hint *)sec->data->d_buf + i;
- rela = find_rela_by_dest(sec, i * sizeof(*hint));
- if (!rela) {
- WARN("can't find rela for unwind_hints[%d]", i);
+ reloc = find_reloc_by_dest(file->elf, sec, i * sizeof(*hint));
+ if (!reloc) {
+ WARN("can't find reloc for unwind_hints[%d]", i);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!insn) {
WARN("can't find insn for unwind_hints[%d]", i);
return -1;
}
- cfa = &insn->state.cfa;
+ insn->hint = true;
if (hint->type == UNWIND_HINT_TYPE_SAVE) {
+ insn->hint = false;
insn->save = true;
- continue;
-
- } else if (hint->type == UNWIND_HINT_TYPE_RESTORE) {
- insn->restore = true;
- insn->hint = true;
continue;
}
- insn->hint = true;
+ if (hint->type == UNWIND_HINT_TYPE_RESTORE) {
+ insn->restore = true;
+ continue;
+ }
- switch (hint->sp_reg) {
- case ORC_REG_UNDEFINED:
- cfa->base = CFI_UNDEFINED;
- break;
- case ORC_REG_SP:
- cfa->base = CFI_SP;
- break;
- case ORC_REG_BP:
- cfa->base = CFI_BP;
- break;
- case ORC_REG_SP_INDIRECT:
- cfa->base = CFI_SP_INDIRECT;
- break;
- case ORC_REG_R10:
- cfa->base = CFI_R10;
- break;
- case ORC_REG_R13:
- cfa->base = CFI_R13;
- break;
- case ORC_REG_DI:
- cfa->base = CFI_DI;
- break;
- case ORC_REG_DX:
- cfa->base = CFI_DX;
- break;
- default:
+ if (hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) {
+ struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset);
+
+ if (sym && sym->bind == STB_GLOBAL) {
+ insn->entry = 1;
+ }
+ }
+
+ if (hint->type == UNWIND_HINT_TYPE_ENTRY) {
+ hint->type = UNWIND_HINT_TYPE_CALL;
+ insn->entry = 1;
+ }
+
+ if (hint->type == UNWIND_HINT_TYPE_FUNC) {
+ insn->cfi = &func_cfi;
+ continue;
+ }
+
+ if (insn->cfi)
+ cfi = *(insn->cfi);
+
+ if (arch_decode_hint_reg(hint->sp_reg, &cfi.cfa.base)) {
WARN_FUNC("unsupported unwind_hint sp base reg %d",
insn->sec, insn->offset, hint->sp_reg);
return -1;
}
- cfa->offset = hint->sp_offset;
- insn->state.type = hint->type;
- insn->state.end = hint->end;
+ cfi.cfa.offset = hint->sp_offset;
+ cfi.type = hint->type;
+ cfi.end = hint->end;
+
+ insn->cfi = cfi_hash_find_or_add(&cfi);
}
return 0;
@@ -1177,32 +1921,166 @@
{
struct section *sec;
struct instruction *insn;
- struct rela *rela;
+ struct reloc *reloc;
sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
if (!sec)
return 0;
- list_for_each_entry(rela, &sec->rela_list, list) {
- if (rela->sym->type != STT_SECTION) {
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s", sec->name);
return -1;
}
- insn = find_insn(file, rela->sym->sec, rela->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
if (!insn) {
WARN("bad .discard.retpoline_safe entry");
return -1;
}
if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC) {
- WARN_FUNC("retpoline_safe hint not an indirect jump/call",
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN &&
+ insn->type != INSN_NOP) {
+ WARN_FUNC("retpoline_safe hint not an indirect jump/call/ret/nop",
insn->sec, insn->offset);
return -1;
}
insn->retpoline_safe = true;
+ }
+
+ return 0;
+}
+
+static int read_instr_hints(struct objtool_file *file)
+{
+ struct section *sec;
+ struct instruction *insn;
+ struct reloc *reloc;
+
+ sec = find_section_by_name(file->elf, ".rela.discard.instr_end");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s", sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!insn) {
+ WARN("bad .discard.instr_end entry");
+ return -1;
+ }
+
+ insn->instr--;
+ }
+
+ sec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s", sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!insn) {
+ WARN("bad .discard.instr_begin entry");
+ return -1;
+ }
+
+ insn->instr++;
+ }
+
+ return 0;
+}
+
+static int read_intra_function_calls(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct section *sec;
+ struct reloc *reloc;
+
+ sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
+ if (!sec)
+ return 0;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ unsigned long dest_off;
+
+ if (reloc->sym->type != STT_SECTION) {
+ WARN("unexpected relocation symbol type in %s",
+ sec->name);
+ return -1;
+ }
+
+ insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ if (!insn) {
+ WARN("bad .discard.intra_function_call entry");
+ return -1;
+ }
+
+ if (insn->type != INSN_CALL) {
+ WARN_FUNC("intra_function_call not a direct call",
+ insn->sec, insn->offset);
+ return -1;
+ }
+
+ /*
+ * Treat intra-function CALLs as JMPs, but with a stack_op.
+ * See add_call_destinations(), which strips stack_ops from
+ * normal CALLs.
+ */
+ insn->type = INSN_JUMP_UNCONDITIONAL;
+
+ dest_off = insn->offset + insn->len + insn->immediate;
+ insn->jump_dest = find_insn(file, insn->sec, dest_off);
+ if (!insn->jump_dest) {
+ WARN_FUNC("can't find call dest at %s+0x%lx",
+ insn->sec, insn->offset,
+ insn->sec->name, dest_off);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int classify_symbols(struct objtool_file *file)
+{
+ struct section *sec;
+ struct symbol *func;
+
+ for_each_sec(file, sec) {
+ list_for_each_entry(func, &sec->symbol_list, list) {
+ if (func->bind != STB_GLOBAL)
+ continue;
+
+ if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+ strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
+ func->static_call_tramp = true;
+
+ if (arch_is_retpoline(func))
+ func->retpoline_thunk = true;
+
+ if (arch_is_rethunk(func))
+ func->return_thunk = true;
+
+ if (arch_is_embedded_insn(func))
+ func->embedded_insn = true;
+
+ if (!strcmp(func->name, "__fentry__"))
+ func->fentry = true;
+
+ if (!strncmp(func->name, "__sanitizer_cov_", 16))
+ func->kcov = true;
+ }
}
return 0;
@@ -1214,9 +2092,14 @@
bool found = false;
/*
- * This searches for the .rodata section or multiple .rodata.func_name
- * sections if -fdata-sections is being used. The .str.1.1 and .str.1.8
- * rodata sections are ignored as they don't contain jump tables.
+ * Search for the following rodata sections, each of which can
+ * potentially contain jump tables:
+ *
+ * - .rodata: can contain GCC switch tables
+ * - .rodata.<func>: same, if -fdata-sections is being used
+ * - .rodata..c_jump_table: contains C annotated jump tables
+ *
+ * .rodata.str1.* sections are ignored; they don't contain jump tables.
*/
for_each_sec(file, sec) {
if (!strncmp(sec->name, ".rodata", 7) &&
@@ -1244,11 +2127,24 @@
return ret;
add_ignores(file);
+ add_uaccess_safe(file);
+ add_cfi_jumptables(file);
- ret = add_nospec_ignores(file);
+ ret = add_ignore_alternatives(file);
if (ret)
return ret;
+ /*
+ * Must be before add_{jump_call}_destination.
+ */
+ ret = classify_symbols(file);
+ if (ret)
+ return ret;
+
+ /*
+ * Must be before add_special_section_alts() as that depends on
+ * jump_dest being set.
+ */
ret = add_jump_destinations(file);
if (ret)
return ret;
@@ -1257,11 +2153,19 @@
if (ret)
return ret;
+ /*
+ * Must be before add_call_destination(); it changes INSN_CALL to
+ * INSN_JUMP.
+ */
+ ret = read_intra_function_calls(file);
+ if (ret)
+ return ret;
+
ret = add_call_destinations(file);
if (ret)
return ret;
- ret = add_switch_table_alts(file);
+ ret = add_jump_table_alts(file);
if (ret)
return ret;
@@ -1273,63 +2177,80 @@
if (ret)
return ret;
+ ret = read_instr_hints(file);
+ if (ret)
+ return ret;
+
return 0;
}
-static bool is_fentry_call(struct instruction *insn)
+static bool is_special_call(struct instruction *insn)
{
- if (insn->type == INSN_CALL &&
- insn->call_dest->type == STT_NOTYPE &&
- !strcmp(insn->call_dest->name, "__fentry__"))
- return true;
+ if (insn->type == INSN_CALL) {
+ struct symbol *dest = insn->call_dest;
+
+ if (!dest)
+ return false;
+
+ if (dest->fentry)
+ return true;
+ }
return false;
}
-static bool has_modified_stack_frame(struct insn_state *state)
+static bool has_modified_stack_frame(struct instruction *insn, struct insn_state *state)
{
+ struct cfi_state *cfi = &state->cfi;
int i;
- if (state->cfa.base != initial_func_cfi.cfa.base ||
- state->cfa.offset != initial_func_cfi.cfa.offset ||
- state->stack_size != initial_func_cfi.cfa.offset ||
- state->drap)
+ if (cfi->cfa.base != initial_func_cfi.cfa.base || cfi->drap)
return true;
- for (i = 0; i < CFI_NUM_REGS; i++)
- if (state->regs[i].base != initial_func_cfi.regs[i].base ||
- state->regs[i].offset != initial_func_cfi.regs[i].offset)
+ if (cfi->cfa.offset != initial_func_cfi.cfa.offset)
+ return true;
+
+ if (cfi->stack_size != initial_func_cfi.cfa.offset)
+ return true;
+
+ for (i = 0; i < CFI_NUM_REGS; i++) {
+ if (cfi->regs[i].base != initial_func_cfi.regs[i].base ||
+ cfi->regs[i].offset != initial_func_cfi.regs[i].offset)
return true;
+ }
return false;
}
static bool has_valid_stack_frame(struct insn_state *state)
{
- if (state->cfa.base == CFI_BP && state->regs[CFI_BP].base == CFI_CFA &&
- state->regs[CFI_BP].offset == -16)
+ struct cfi_state *cfi = &state->cfi;
+
+ if (cfi->cfa.base == CFI_BP && cfi->regs[CFI_BP].base == CFI_CFA &&
+ cfi->regs[CFI_BP].offset == -16)
return true;
- if (state->drap && state->regs[CFI_BP].base == CFI_BP)
+ if (cfi->drap && cfi->regs[CFI_BP].base == CFI_BP)
return true;
return false;
}
-static int update_insn_state_regs(struct instruction *insn, struct insn_state *state)
+static int update_cfi_state_regs(struct instruction *insn,
+ struct cfi_state *cfi,
+ struct stack_op *op)
{
- struct cfi_reg *cfa = &state->cfa;
- struct stack_op *op = &insn->stack_op;
+ struct cfi_reg *cfa = &cfi->cfa;
if (cfa->base != CFI_SP && cfa->base != CFI_SP_INDIRECT)
return 0;
/* push */
- if (op->dest.type == OP_DEST_PUSH)
+ if (op->dest.type == OP_DEST_PUSH || op->dest.type == OP_DEST_PUSHF)
cfa->offset += 8;
/* pop */
- if (op->src.type == OP_SRC_POP)
+ if (op->src.type == OP_SRC_POP || op->src.type == OP_SRC_POPF)
cfa->offset -= 8;
/* add immediate to sp */
@@ -1340,20 +2261,19 @@
return 0;
}
-static void save_reg(struct insn_state *state, unsigned char reg, int base,
- int offset)
+static void save_reg(struct cfi_state *cfi, unsigned char reg, int base, int offset)
{
if (arch_callee_saved_reg(reg) &&
- state->regs[reg].base == CFI_UNDEFINED) {
- state->regs[reg].base = base;
- state->regs[reg].offset = offset;
+ cfi->regs[reg].base == CFI_UNDEFINED) {
+ cfi->regs[reg].base = base;
+ cfi->regs[reg].offset = offset;
}
}
-static void restore_reg(struct insn_state *state, unsigned char reg)
+static void restore_reg(struct cfi_state *cfi, unsigned char reg)
{
- state->regs[reg].base = CFI_UNDEFINED;
- state->regs[reg].offset = 0;
+ cfi->regs[reg].base = initial_func_cfi.regs[reg].base;
+ cfi->regs[reg].offset = initial_func_cfi.regs[reg].offset;
}
/*
@@ -1409,11 +2329,11 @@
* 41 5d pop %r13
* c3 retq
*/
-static int update_insn_state(struct instruction *insn, struct insn_state *state)
+static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
+ struct stack_op *op)
{
- struct stack_op *op = &insn->stack_op;
- struct cfi_reg *cfa = &state->cfa;
- struct cfi_reg *regs = state->regs;
+ struct cfi_reg *cfa = &cfi->cfa;
+ struct cfi_reg *regs = cfi->regs;
/* stack operations don't make sense with an undefined CFA */
if (cfa->base == CFI_UNDEFINED) {
@@ -1424,8 +2344,9 @@
return 0;
}
- if (state->type == ORC_TYPE_REGS || state->type == ORC_TYPE_REGS_IRET)
- return update_insn_state_regs(insn, state);
+ if (cfi->type == UNWIND_HINT_TYPE_REGS ||
+ cfi->type == UNWIND_HINT_TYPE_REGS_PARTIAL)
+ return update_cfi_state_regs(insn, cfi, op);
switch (op->dest.type) {
@@ -1440,16 +2361,16 @@
/* mov %rsp, %rbp */
cfa->base = op->dest.reg;
- state->bp_scratch = false;
+ cfi->bp_scratch = false;
}
else if (op->src.reg == CFI_SP &&
- op->dest.reg == CFI_BP && state->drap) {
+ op->dest.reg == CFI_BP && cfi->drap) {
/* drap: mov %rsp, %rbp */
regs[CFI_BP].base = CFI_BP;
- regs[CFI_BP].offset = -state->stack_size;
- state->bp_scratch = false;
+ regs[CFI_BP].offset = -cfi->stack_size;
+ cfi->bp_scratch = false;
}
else if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
@@ -1464,8 +2385,8 @@
* ...
* mov %rax, %rsp
*/
- state->vals[op->dest.reg].base = CFI_CFA;
- state->vals[op->dest.reg].offset = -state->stack_size;
+ cfi->vals[op->dest.reg].base = CFI_CFA;
+ cfi->vals[op->dest.reg].offset = -cfi->stack_size;
}
else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP &&
@@ -1476,14 +2397,14 @@
*
* Restore the original stack pointer (Clang).
*/
- state->stack_size = -state->regs[CFI_BP].offset;
+ cfi->stack_size = -cfi->regs[CFI_BP].offset;
}
else if (op->dest.reg == cfa->base) {
/* mov %reg, %rsp */
if (cfa->base == CFI_SP &&
- state->vals[op->src.reg].base == CFI_CFA) {
+ cfi->vals[op->src.reg].base == CFI_CFA) {
/*
* This is needed for the rare case
@@ -1493,8 +2414,8 @@
* ...
* mov %rcx, %rsp
*/
- cfa->offset = -state->vals[op->src.reg].offset;
- state->stack_size = cfa->offset;
+ cfa->offset = -cfi->vals[op->src.reg].offset;
+ cfi->stack_size = cfa->offset;
} else {
cfa->base = CFI_UNDEFINED;
@@ -1508,7 +2429,7 @@
if (op->dest.reg == CFI_SP && op->src.reg == CFI_SP) {
/* add imm, %rsp */
- state->stack_size -= op->src.offset;
+ cfi->stack_size -= op->src.offset;
if (cfa->base == CFI_SP)
cfa->offset -= op->src.offset;
break;
@@ -1517,14 +2438,14 @@
if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) {
/* lea disp(%rbp), %rsp */
- state->stack_size = -(op->src.offset + regs[CFI_BP].offset);
+ cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset);
break;
}
if (op->src.reg == CFI_SP && cfa->base == CFI_SP) {
/* drap: lea disp(%rsp), %drap */
- state->drap_reg = op->dest.reg;
+ cfi->drap_reg = op->dest.reg;
/*
* lea disp(%rsp), %reg
@@ -1536,25 +2457,25 @@
* ...
* mov %rcx, %rsp
*/
- state->vals[op->dest.reg].base = CFI_CFA;
- state->vals[op->dest.reg].offset = \
- -state->stack_size + op->src.offset;
+ cfi->vals[op->dest.reg].base = CFI_CFA;
+ cfi->vals[op->dest.reg].offset = \
+ -cfi->stack_size + op->src.offset;
break;
}
- if (state->drap && op->dest.reg == CFI_SP &&
- op->src.reg == state->drap_reg) {
+ if (cfi->drap && op->dest.reg == CFI_SP &&
+ op->src.reg == cfi->drap_reg) {
/* drap: lea disp(%drap), %rsp */
cfa->base = CFI_SP;
- cfa->offset = state->stack_size = -op->src.offset;
- state->drap_reg = CFI_UNDEFINED;
- state->drap = false;
+ cfa->offset = cfi->stack_size = -op->src.offset;
+ cfi->drap_reg = CFI_UNDEFINED;
+ cfi->drap = false;
break;
}
- if (op->dest.reg == state->cfa.base) {
+ if (op->dest.reg == cfi->cfa.base) {
WARN_FUNC("unsupported stack register modification",
insn->sec, insn->offset);
return -1;
@@ -1564,18 +2485,18 @@
case OP_SRC_AND:
if (op->dest.reg != CFI_SP ||
- (state->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) ||
- (state->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) {
+ (cfi->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) ||
+ (cfi->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) {
WARN_FUNC("unsupported stack pointer realignment",
insn->sec, insn->offset);
return -1;
}
- if (state->drap_reg != CFI_UNDEFINED) {
+ if (cfi->drap_reg != CFI_UNDEFINED) {
/* drap: and imm, %rsp */
- cfa->base = state->drap_reg;
- cfa->offset = state->stack_size = 0;
- state->drap = true;
+ cfa->base = cfi->drap_reg;
+ cfa->offset = cfi->stack_size = 0;
+ cfi->drap = true;
}
/*
@@ -1586,57 +2507,56 @@
break;
case OP_SRC_POP:
- if (!state->drap && op->dest.type == OP_DEST_REG &&
- op->dest.reg == cfa->base) {
+ case OP_SRC_POPF:
+ if (!cfi->drap && op->dest.reg == cfa->base) {
/* pop %rbp */
cfa->base = CFI_SP;
}
- if (state->drap && cfa->base == CFI_BP_INDIRECT &&
- op->dest.type == OP_DEST_REG &&
- op->dest.reg == state->drap_reg &&
- state->drap_offset == -state->stack_size) {
+ if (cfi->drap && cfa->base == CFI_BP_INDIRECT &&
+ op->dest.reg == cfi->drap_reg &&
+ cfi->drap_offset == -cfi->stack_size) {
/* drap: pop %drap */
- cfa->base = state->drap_reg;
+ cfa->base = cfi->drap_reg;
cfa->offset = 0;
- state->drap_offset = -1;
+ cfi->drap_offset = -1;
- } else if (regs[op->dest.reg].offset == -state->stack_size) {
+ } else if (regs[op->dest.reg].offset == -cfi->stack_size) {
/* pop %reg */
- restore_reg(state, op->dest.reg);
+ restore_reg(cfi, op->dest.reg);
}
- state->stack_size -= 8;
+ cfi->stack_size -= 8;
if (cfa->base == CFI_SP)
cfa->offset -= 8;
break;
case OP_SRC_REG_INDIRECT:
- if (state->drap && op->src.reg == CFI_BP &&
- op->src.offset == state->drap_offset) {
+ if (cfi->drap && op->src.reg == CFI_BP &&
+ op->src.offset == cfi->drap_offset) {
/* drap: mov disp(%rbp), %drap */
- cfa->base = state->drap_reg;
+ cfa->base = cfi->drap_reg;
cfa->offset = 0;
- state->drap_offset = -1;
+ cfi->drap_offset = -1;
}
- if (state->drap && op->src.reg == CFI_BP &&
+ if (cfi->drap && op->src.reg == CFI_BP &&
op->src.offset == regs[op->dest.reg].offset) {
/* drap: mov disp(%rbp), %reg */
- restore_reg(state, op->dest.reg);
+ restore_reg(cfi, op->dest.reg);
} else if (op->src.reg == cfa->base &&
op->src.offset == regs[op->dest.reg].offset + cfa->offset) {
/* mov disp(%rbp), %reg */
/* mov disp(%rsp), %reg */
- restore_reg(state, op->dest.reg);
+ restore_reg(cfi, op->dest.reg);
}
break;
@@ -1650,78 +2570,77 @@
break;
case OP_DEST_PUSH:
- state->stack_size += 8;
+ case OP_DEST_PUSHF:
+ cfi->stack_size += 8;
if (cfa->base == CFI_SP)
cfa->offset += 8;
if (op->src.type != OP_SRC_REG)
break;
- if (state->drap) {
- if (op->src.reg == cfa->base && op->src.reg == state->drap_reg) {
+ if (cfi->drap) {
+ if (op->src.reg == cfa->base && op->src.reg == cfi->drap_reg) {
/* drap: push %drap */
cfa->base = CFI_BP_INDIRECT;
- cfa->offset = -state->stack_size;
+ cfa->offset = -cfi->stack_size;
/* save drap so we know when to restore it */
- state->drap_offset = -state->stack_size;
+ cfi->drap_offset = -cfi->stack_size;
- } else if (op->src.reg == CFI_BP && cfa->base == state->drap_reg) {
+ } else if (op->src.reg == CFI_BP && cfa->base == cfi->drap_reg) {
/* drap: push %rbp */
- state->stack_size = 0;
+ cfi->stack_size = 0;
- } else if (regs[op->src.reg].base == CFI_UNDEFINED) {
+ } else {
/* drap: push %reg */
- save_reg(state, op->src.reg, CFI_BP, -state->stack_size);
+ save_reg(cfi, op->src.reg, CFI_BP, -cfi->stack_size);
}
} else {
/* push %reg */
- save_reg(state, op->src.reg, CFI_CFA, -state->stack_size);
+ save_reg(cfi, op->src.reg, CFI_CFA, -cfi->stack_size);
}
/* detect when asm code uses rbp as a scratch register */
if (!no_fp && insn->func && op->src.reg == CFI_BP &&
cfa->base != CFI_BP)
- state->bp_scratch = true;
+ cfi->bp_scratch = true;
break;
case OP_DEST_REG_INDIRECT:
- if (state->drap) {
- if (op->src.reg == cfa->base && op->src.reg == state->drap_reg) {
+ if (cfi->drap) {
+ if (op->src.reg == cfa->base && op->src.reg == cfi->drap_reg) {
/* drap: mov %drap, disp(%rbp) */
cfa->base = CFI_BP_INDIRECT;
cfa->offset = op->dest.offset;
/* save drap offset so we know when to restore it */
- state->drap_offset = op->dest.offset;
- }
-
- else if (regs[op->src.reg].base == CFI_UNDEFINED) {
+ cfi->drap_offset = op->dest.offset;
+ } else {
/* drap: mov reg, disp(%rbp) */
- save_reg(state, op->src.reg, CFI_BP, op->dest.offset);
+ save_reg(cfi, op->src.reg, CFI_BP, op->dest.offset);
}
} else if (op->dest.reg == cfa->base) {
/* mov reg, disp(%rbp) */
/* mov reg, disp(%rsp) */
- save_reg(state, op->src.reg, CFI_CFA,
- op->dest.offset - state->cfa.offset);
+ save_reg(cfi, op->src.reg, CFI_CFA,
+ op->dest.offset - cfi->cfa.offset);
}
break;
case OP_DEST_LEAVE:
- if ((!state->drap && cfa->base != CFI_BP) ||
- (state->drap && cfa->base != state->drap_reg)) {
+ if ((!cfi->drap && cfa->base != CFI_BP) ||
+ (cfi->drap && cfa->base != cfi->drap_reg)) {
WARN_FUNC("leave instruction with modified stack frame",
insn->sec, insn->offset);
return -1;
@@ -1729,10 +2648,10 @@
/* leave (mov %rbp, %rsp; pop %rbp) */
- state->stack_size = -state->regs[CFI_BP].offset - 8;
- restore_reg(state, CFI_BP);
+ cfi->stack_size = -cfi->regs[CFI_BP].offset - 8;
+ restore_reg(cfi, CFI_BP);
- if (!state->drap) {
+ if (!cfi->drap) {
cfa->base = CFI_SP;
cfa->offset -= 8;
}
@@ -1740,14 +2659,14 @@
break;
case OP_DEST_MEM:
- if (op->src.type != OP_SRC_POP) {
+ if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) {
WARN_FUNC("unknown stack-related memory operation",
insn->sec, insn->offset);
return -1;
}
/* pop mem */
- state->stack_size -= 8;
+ cfi->stack_size -= 8;
if (cfa->base == CFI_SP)
cfa->offset -= 8;
@@ -1762,46 +2681,260 @@
return 0;
}
-static bool insn_state_match(struct instruction *insn, struct insn_state *state)
+/*
+ * The stack layouts of alternatives instructions can sometimes diverge when
+ * they have stack modifications. That's fine as long as the potential stack
+ * layouts don't conflict at any given potential instruction boundary.
+ *
+ * Flatten the CFIs of the different alternative code streams (both original
+ * and replacement) into a single shared CFI array which can be used to detect
+ * conflicts and nicely feed a linear array of ORC entries to the unwinder.
+ */
+static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn)
{
- struct insn_state *state1 = &insn->state, *state2 = state;
+ struct cfi_state **alt_cfi;
+ int group_off;
+
+ if (!insn->alt_group)
+ return 0;
+
+ if (!insn->cfi) {
+ WARN("CFI missing");
+ return -1;
+ }
+
+ alt_cfi = insn->alt_group->cfi;
+ group_off = insn->offset - insn->alt_group->first_insn->offset;
+
+ if (!alt_cfi[group_off]) {
+ alt_cfi[group_off] = insn->cfi;
+ } else {
+ if (cficmp(alt_cfi[group_off], insn->cfi)) {
+ WARN_FUNC("stack layout conflict in alternatives",
+ insn->sec, insn->offset);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
+{
+ struct stack_op *op;
+
+ list_for_each_entry(op, &insn->stack_ops, list) {
+
+ if (update_cfi_state(insn, &state->cfi, op))
+ return 1;
+
+ if (op->dest.type == OP_DEST_PUSHF) {
+ if (!state->uaccess_stack) {
+ state->uaccess_stack = 1;
+ } else if (state->uaccess_stack >> 31) {
+ WARN_FUNC("PUSHF stack exhausted",
+ insn->sec, insn->offset);
+ return 1;
+ }
+ state->uaccess_stack <<= 1;
+ state->uaccess_stack |= state->uaccess;
+ }
+
+ if (op->src.type == OP_SRC_POPF) {
+ if (state->uaccess_stack) {
+ state->uaccess = state->uaccess_stack & 1;
+ state->uaccess_stack >>= 1;
+ if (state->uaccess_stack == 1)
+ state->uaccess_stack = 0;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
+{
+ struct cfi_state *cfi1 = insn->cfi;
int i;
- if (memcmp(&state1->cfa, &state2->cfa, sizeof(state1->cfa))) {
+ if (!cfi1) {
+ WARN("CFI missing");
+ return false;
+ }
+
+ if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) {
+
WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
insn->sec, insn->offset,
- state1->cfa.base, state1->cfa.offset,
- state2->cfa.base, state2->cfa.offset);
+ cfi1->cfa.base, cfi1->cfa.offset,
+ cfi2->cfa.base, cfi2->cfa.offset);
- } else if (memcmp(&state1->regs, &state2->regs, sizeof(state1->regs))) {
+ } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) {
for (i = 0; i < CFI_NUM_REGS; i++) {
- if (!memcmp(&state1->regs[i], &state2->regs[i],
+ if (!memcmp(&cfi1->regs[i], &cfi2->regs[i],
sizeof(struct cfi_reg)))
continue;
WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d",
insn->sec, insn->offset,
- i, state1->regs[i].base, state1->regs[i].offset,
- i, state2->regs[i].base, state2->regs[i].offset);
+ i, cfi1->regs[i].base, cfi1->regs[i].offset,
+ i, cfi2->regs[i].base, cfi2->regs[i].offset);
break;
}
- } else if (state1->type != state2->type) {
- WARN_FUNC("stack state mismatch: type1=%d type2=%d",
- insn->sec, insn->offset, state1->type, state2->type);
+ } else if (cfi1->type != cfi2->type) {
- } else if (state1->drap != state2->drap ||
- (state1->drap && state1->drap_reg != state2->drap_reg) ||
- (state1->drap && state1->drap_offset != state2->drap_offset)) {
+ WARN_FUNC("stack state mismatch: type1=%d type2=%d",
+ insn->sec, insn->offset, cfi1->type, cfi2->type);
+
+ } else if (cfi1->drap != cfi2->drap ||
+ (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) ||
+ (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) {
+
WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)",
insn->sec, insn->offset,
- state1->drap, state1->drap_reg, state1->drap_offset,
- state2->drap, state2->drap_reg, state2->drap_offset);
+ cfi1->drap, cfi1->drap_reg, cfi1->drap_offset,
+ cfi2->drap, cfi2->drap_reg, cfi2->drap_offset);
} else
return true;
return false;
+}
+
+static inline bool func_uaccess_safe(struct symbol *func)
+{
+ if (func)
+ return func->uaccess_safe;
+
+ return false;
+}
+
+static inline const char *call_dest_name(struct instruction *insn)
+{
+ if (insn->call_dest)
+ return insn->call_dest->name;
+
+ return "{dynamic}";
+}
+
+static inline bool noinstr_call_dest(struct symbol *func)
+{
+ /*
+ * We can't deal with indirect function calls at present;
+ * assume they're instrumented.
+ */
+ if (!func)
+ return false;
+
+ /*
+ * If the symbol is from a noinstr section; we good.
+ */
+ if (func->sec->noinstr)
+ return true;
+
+ /*
+ * The __ubsan_handle_*() calls are like WARN(), they only happen when
+ * something 'BAD' happened. At the risk of taking the machine down,
+ * let them proceed to get the message out.
+ */
+ if (!strncmp(func->name, "__ubsan_handle_", 15))
+ return true;
+
+ return false;
+}
+
+static int validate_call(struct instruction *insn, struct insn_state *state)
+{
+ if (state->noinstr && state->instr <= 0 &&
+ !noinstr_call_dest(insn->call_dest)) {
+ WARN_FUNC("call to %s() leaves .noinstr.text section",
+ insn->sec, insn->offset, call_dest_name(insn));
+ return 1;
+ }
+
+ if (state->uaccess && !func_uaccess_safe(insn->call_dest)) {
+ WARN_FUNC("call to %s() with UACCESS enabled",
+ insn->sec, insn->offset, call_dest_name(insn));
+ return 1;
+ }
+
+ if (state->df) {
+ WARN_FUNC("call to %s() with DF set",
+ insn->sec, insn->offset, call_dest_name(insn));
+ return 1;
+ }
+
+ return 0;
+}
+
+static int validate_sibling_call(struct instruction *insn, struct insn_state *state)
+{
+ if (has_modified_stack_frame(insn, state)) {
+ WARN_FUNC("sibling call from callable instruction with modified stack frame",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ return validate_call(insn, state);
+}
+
+static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state)
+{
+ if (state->noinstr && state->instr > 0) {
+ WARN_FUNC("return with instrumentation enabled",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (state->uaccess && !func_uaccess_safe(func)) {
+ WARN_FUNC("return with UACCESS enabled",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (!state->uaccess && func_uaccess_safe(func)) {
+ WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (state->df) {
+ WARN_FUNC("return with DF set",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (func && has_modified_stack_frame(insn, state)) {
+ WARN_FUNC("return with modified stack frame",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ if (state->cfi.bp_scratch) {
+ WARN_FUNC("BP used as a scratch register",
+ insn->sec, insn->offset);
+ return 1;
+ }
+
+ return 0;
+}
+
+static struct instruction *next_insn_to_validate(struct objtool_file *file,
+ struct instruction *insn)
+{
+ struct alt_group *alt_group = insn->alt_group;
+
+ /*
+ * Simulate the fact that alternatives are patched in-place. When the
+ * end of a replacement alt_group is reached, redirect objtool flow to
+ * the end of the original alt_group.
+ */
+ if (alt_group && insn == alt_group->last_insn && alt_group->orig_group)
+ return next_insn_same_sec(file, alt_group->orig_group->last_insn);
+
+ return next_insn_same_sec(file, insn);
}
/*
@@ -1810,26 +2943,19 @@
* each instruction and validate all the rules described in
* tools/objtool/Documentation/stack-validation.txt.
*/
-static int validate_branch(struct objtool_file *file, struct instruction *first,
- struct insn_state state)
+static int validate_branch(struct objtool_file *file, struct symbol *func,
+ struct instruction *insn, struct insn_state state)
{
struct alternative *alt;
- struct instruction *insn, *next_insn;
+ struct instruction *next_insn, *prev_insn = NULL;
struct section *sec;
- struct symbol *func = NULL;
+ u8 visited;
int ret;
- insn = first;
sec = insn->sec;
- if (insn->alt_group && list_empty(&insn->alts)) {
- WARN_FUNC("don't know how to handle branch to middle of alternative instruction group",
- sec, insn->offset);
- return 1;
- }
-
while (1) {
- next_insn = next_insn_same_sec(file, insn);
+ next_insn = next_insn_to_validate(file, insn);
if (file->c_file && func && insn->func && func != insn->func->pfunc) {
WARN("%s() falls through to next function %s()",
@@ -1837,21 +2963,25 @@
return 1;
}
- if (insn->func)
- func = insn->func->pfunc;
-
if (func && insn->ignore) {
WARN_FUNC("BUG: why am I validating an ignored function?",
sec, insn->offset);
return 1;
}
- if (insn->visited) {
- if (!insn->hint && !insn_state_match(insn, &state))
+ visited = VISITED_BRANCH << state.uaccess;
+ if (insn->visited & VISITED_BRANCH_MASK) {
+ if (!insn->hint && !insn_cfi_match(insn, &state.cfi))
return 1;
- return 0;
+ if (insn->visited & visited)
+ return 0;
+ } else {
+ nr_insns_visited++;
}
+
+ if (state.noinstr)
+ state.instr += insn->instr;
if (insn->hint) {
if (insn->restore) {
@@ -1859,7 +2989,8 @@
i = insn;
save_insn = NULL;
- func_for_each_insn_continue_reverse(file, insn->func, i) {
+
+ sym_for_each_insn_continue_reverse(file, func, i) {
if (i->save) {
save_insn = i;
break;
@@ -1873,89 +3004,97 @@
}
if (!save_insn->visited) {
- /*
- * Oops, no state to copy yet.
- * Hopefully we can reach this
- * instruction from another branch
- * after the save insn has been
- * visited.
- */
- if (insn == first)
- return 0;
-
WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
sec, insn->offset);
return 1;
}
- insn->state = save_insn->state;
+ insn->cfi = save_insn->cfi;
+ nr_cfi_reused++;
}
- state = insn->state;
+ state.cfi = *insn->cfi;
+ } else {
+ /* XXX track if we actually changed state.cfi */
- } else
- insn->state = state;
-
- insn->visited = true;
-
- if (!insn->ignore_alts) {
- list_for_each_entry(alt, &insn->alts, list) {
- ret = validate_branch(file, alt->insn, state);
- if (ret)
- return 1;
+ if (prev_insn && !cficmp(prev_insn->cfi, &state.cfi)) {
+ insn->cfi = prev_insn->cfi;
+ nr_cfi_reused++;
+ } else {
+ insn->cfi = cfi_hash_find_or_add(&state.cfi);
}
}
+
+ insn->visited |= visited;
+
+ if (propagate_alt_cfi(file, insn))
+ return 1;
+
+ if (!insn->ignore_alts && !list_empty(&insn->alts)) {
+ bool skip_orig = false;
+
+ list_for_each_entry(alt, &insn->alts, list) {
+ if (alt->skip_orig)
+ skip_orig = true;
+
+ ret = validate_branch(file, func, alt->insn, state);
+ if (ret) {
+ if (backtrace)
+ BT_FUNC("(alt)", insn);
+ return ret;
+ }
+ }
+
+ if (skip_orig)
+ return 0;
+ }
+
+ if (handle_insn_ops(insn, &state))
+ return 1;
switch (insn->type) {
case INSN_RETURN:
- if (func && has_modified_stack_frame(&state)) {
- WARN_FUNC("return with modified stack frame",
- sec, insn->offset);
- return 1;
+ if (sls && !insn->retpoline_safe &&
+ next_insn && next_insn->type != INSN_TRAP) {
+ WARN_FUNC("missing int3 after ret",
+ insn->sec, insn->offset);
}
-
- if (state.bp_scratch) {
- WARN("%s uses BP as a scratch register",
- insn->func->name);
- return 1;
- }
-
- return 0;
+ return validate_return(func, insn, &state);
case INSN_CALL:
- if (is_fentry_call(insn))
- break;
-
- ret = dead_end_function(file, insn->call_dest);
- if (ret == 1)
- return 0;
- if (ret == -1)
- return 1;
-
- /* fallthrough */
case INSN_CALL_DYNAMIC:
- if (!no_fp && func && !has_valid_stack_frame(&state)) {
+ ret = validate_call(insn, &state);
+ if (ret)
+ return ret;
+
+ if (!no_fp && func && !is_special_call(insn) &&
+ !has_valid_stack_frame(&state)) {
WARN_FUNC("call without frame pointer save/setup",
sec, insn->offset);
return 1;
}
+
+ if (dead_end_function(file, insn->call_dest))
+ return 0;
+
break;
case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
- if (insn->jump_dest &&
- (!func || !insn->jump_dest->func ||
- insn->jump_dest->func->pfunc == func)) {
- ret = validate_branch(file, insn->jump_dest,
- state);
+ if (is_sibling_call(insn)) {
+ ret = validate_sibling_call(insn, &state);
if (ret)
- return 1;
+ return ret;
- } else if (func && has_modified_stack_frame(&state)) {
- WARN_FUNC("sibling call from callable instruction with modified stack frame",
- sec, insn->offset);
- return 1;
+ } else if (insn->jump_dest) {
+ ret = validate_branch(file, func,
+ insn->jump_dest, state);
+ if (ret) {
+ if (backtrace)
+ BT_FUNC("(branch)", insn);
+ return ret;
+ }
}
if (insn->type == INSN_JUMP_UNCONDITIONAL)
@@ -1964,14 +3103,24 @@
break;
case INSN_JUMP_DYNAMIC:
- if (func && list_empty(&insn->alts) &&
- has_modified_stack_frame(&state)) {
- WARN_FUNC("sibling call from callable instruction with modified stack frame",
- sec, insn->offset);
- return 1;
+ if (sls && !insn->retpoline_safe &&
+ next_insn && next_insn->type != INSN_TRAP) {
+ WARN_FUNC("missing int3 after indirect jump",
+ insn->sec, insn->offset);
}
- return 0;
+ /* fallthrough */
+ case INSN_JUMP_DYNAMIC_CONDITIONAL:
+ if (is_sibling_call(insn)) {
+ ret = validate_sibling_call(insn, &state);
+ if (ret)
+ return ret;
+ }
+
+ if (insn->type == INSN_JUMP_DYNAMIC)
+ return 0;
+
+ break;
case INSN_CONTEXT_SWITCH:
if (func && (!next_insn || !next_insn->hint)) {
@@ -1981,10 +3130,45 @@
}
return 0;
- case INSN_STACK:
- if (update_insn_state(insn, &state))
+ case INSN_STAC:
+ if (state.uaccess) {
+ WARN_FUNC("recursive UACCESS enable", sec, insn->offset);
return 1;
+ }
+ state.uaccess = true;
+ break;
+
+ case INSN_CLAC:
+ if (!state.uaccess && func) {
+ WARN_FUNC("redundant UACCESS disable", sec, insn->offset);
+ return 1;
+ }
+
+ if (func_uaccess_safe(func) && !state.uaccess_stack) {
+ WARN_FUNC("UACCESS-safe disables UACCESS", sec, insn->offset);
+ return 1;
+ }
+
+ state.uaccess = false;
+ break;
+
+ case INSN_STD:
+ if (state.df) {
+ WARN_FUNC("recursive STD", sec, insn->offset);
+ return 1;
+ }
+
+ state.df = true;
+ break;
+
+ case INSN_CLD:
+ if (!state.df && func) {
+ WARN_FUNC("redundant CLD", sec, insn->offset);
+ return 1;
+ }
+
+ state.df = false;
break;
default:
@@ -1995,34 +3179,186 @@
return 0;
if (!next_insn) {
- if (state.cfa.base == CFI_UNDEFINED)
+ if (state.cfi.cfa.base == CFI_UNDEFINED)
return 0;
WARN("%s: unexpected end of section", sec->name);
return 1;
}
+ prev_insn = insn;
insn = next_insn;
}
return 0;
}
-static int validate_unwind_hints(struct objtool_file *file)
+static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
{
struct instruction *insn;
- int ret, warnings = 0;
struct insn_state state;
+ int ret, warnings = 0;
if (!file->hints)
return 0;
- clear_insn_state(&state);
+ init_insn_state(&state, sec);
- for_each_insn(file, insn) {
+ if (sec) {
+ insn = find_insn(file, sec, 0);
+ if (!insn)
+ return 0;
+ } else {
+ insn = list_first_entry(&file->insn_list, typeof(*insn), list);
+ }
+
+ while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) {
if (insn->hint && !insn->visited) {
- ret = validate_branch(file, insn, state);
+ ret = validate_branch(file, insn->func, insn, state);
+ if (ret && backtrace)
+ BT_FUNC("<=== (hint)", insn);
warnings += ret;
}
+
+ insn = list_next_entry(insn, list);
+ }
+
+ return warnings;
+}
+
+/*
+ * Validate rethunk entry constraint: must untrain RET before the first RET.
+ *
+ * Follow every branch (intra-function) and ensure ANNOTATE_UNRET_END comes
+ * before an actual RET instruction.
+ */
+static int validate_entry(struct objtool_file *file, struct instruction *insn)
+{
+ struct instruction *next, *dest;
+ int ret, warnings = 0;
+
+ for (;;) {
+ next = next_insn_to_validate(file, insn);
+
+ if (insn->visited & VISITED_ENTRY)
+ return 0;
+
+ insn->visited |= VISITED_ENTRY;
+
+ if (!insn->ignore_alts && !list_empty(&insn->alts)) {
+ struct alternative *alt;
+ bool skip_orig = false;
+
+ list_for_each_entry(alt, &insn->alts, list) {
+ if (alt->skip_orig)
+ skip_orig = true;
+
+ ret = validate_entry(file, alt->insn);
+ if (ret) {
+ if (backtrace)
+ BT_FUNC("(alt)", insn);
+ return ret;
+ }
+ }
+
+ if (skip_orig)
+ return 0;
+ }
+
+ switch (insn->type) {
+
+ case INSN_CALL_DYNAMIC:
+ case INSN_JUMP_DYNAMIC:
+ case INSN_JUMP_DYNAMIC_CONDITIONAL:
+ WARN_FUNC("early indirect call", insn->sec, insn->offset);
+ return 1;
+
+ case INSN_JUMP_UNCONDITIONAL:
+ case INSN_JUMP_CONDITIONAL:
+ if (!is_sibling_call(insn)) {
+ if (!insn->jump_dest) {
+ WARN_FUNC("unresolved jump target after linking?!?",
+ insn->sec, insn->offset);
+ return -1;
+ }
+ ret = validate_entry(file, insn->jump_dest);
+ if (ret) {
+ if (backtrace) {
+ BT_FUNC("(branch%s)", insn,
+ insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : "");
+ }
+ return ret;
+ }
+
+ if (insn->type == INSN_JUMP_UNCONDITIONAL)
+ return 0;
+
+ break;
+ }
+
+ /* fallthrough */
+ case INSN_CALL:
+ dest = find_insn(file, insn->call_dest->sec,
+ insn->call_dest->offset);
+ if (!dest) {
+ WARN("Unresolved function after linking!?: %s",
+ insn->call_dest->name);
+ return -1;
+ }
+
+ ret = validate_entry(file, dest);
+ if (ret) {
+ if (backtrace)
+ BT_FUNC("(call)", insn);
+ return ret;
+ }
+ /*
+ * If a call returns without error, it must have seen UNTRAIN_RET.
+ * Therefore any non-error return is a success.
+ */
+ return 0;
+
+ case INSN_RETURN:
+ WARN_FUNC("RET before UNTRAIN", insn->sec, insn->offset);
+ return 1;
+
+ case INSN_NOP:
+ if (insn->retpoline_safe)
+ return 0;
+ break;
+
+ default:
+ break;
+ }
+
+ if (!next) {
+ WARN_FUNC("teh end!", insn->sec, insn->offset);
+ return -1;
+ }
+ insn = next;
+ }
+
+ return warnings;
+}
+
+/*
+ * Validate that all branches starting at 'insn->entry' encounter UNRET_END
+ * before RET.
+ */
+static int validate_unret(struct objtool_file *file)
+{
+ struct instruction *insn;
+ int ret, warnings = 0;
+
+ for_each_insn(file, insn) {
+ if (!insn->entry)
+ continue;
+
+ ret = validate_entry(file, insn);
+ if (ret < 0) {
+ WARN_FUNC("Failed UNRET validation", insn->sec, insn->offset);
+ return ret;
+ }
+ warnings += ret;
}
return warnings;
@@ -2035,7 +3371,8 @@
for_each_insn(file, insn) {
if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC)
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN)
continue;
if (insn->retpoline_safe)
@@ -2050,9 +3387,17 @@
if (!strcmp(insn->sec->name, ".init.text") && !module)
continue;
- WARN_FUNC("indirect %s found in RETPOLINE build",
- insn->sec, insn->offset,
- insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
+ if (insn->type == INSN_RETURN) {
+ if (rethunk) {
+ WARN_FUNC("'naked' return found in RETHUNK build",
+ insn->sec, insn->offset);
+ } else
+ continue;
+ } else {
+ WARN_FUNC("indirect %s found in RETPOLINE build",
+ insn->sec, insn->offset,
+ insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
+ }
warnings++;
}
@@ -2073,11 +3418,12 @@
"__ubsan_handle_builtin_unreachable"));
}
-static bool ignore_unreachable_insn(struct instruction *insn)
+static bool ignore_unreachable_insn(struct objtool_file *file, struct instruction *insn)
{
int i;
+ struct instruction *prev_insn;
- if (insn->ignore || insn->type == INSN_NOP)
+ if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP)
return true;
/*
@@ -2100,8 +3446,11 @@
* __builtin_unreachable(). The BUG() macro has an unreachable() after
* the UD2, which causes GCC's undefined trap logic to emit another UD2
* (or occasionally a JMP to UD2).
+ *
+ * It may also insert a UD2 after calling a __noreturn function.
*/
- if (list_prev_entry(insn, list)->dead_end &&
+ prev_insn = list_prev_entry(insn, list);
+ if ((prev_insn->dead_end || dead_end_function(file, prev_insn->call_dest)) &&
(insn->type == INSN_BUG ||
(insn->type == INSN_JUMP_UNCONDITIONAL &&
insn->jump_dest && insn->jump_dest->type == INSN_BUG)))
@@ -2137,33 +3486,81 @@
return false;
}
+static int validate_symbol(struct objtool_file *file, struct section *sec,
+ struct symbol *sym, struct insn_state *state)
+{
+ struct instruction *insn;
+ int ret;
+
+ if (!sym->len) {
+ WARN("%s() is missing an ELF size annotation", sym->name);
+ return 1;
+ }
+
+ if (sym->pfunc != sym || sym->alias != sym)
+ return 0;
+
+ insn = find_insn(file, sec, sym->offset);
+ if (!insn || insn->ignore || insn->visited)
+ return 0;
+
+ state->uaccess = sym->uaccess_safe;
+
+ ret = validate_branch(file, insn->func, insn, *state);
+ if (ret && backtrace)
+ BT_FUNC("<=== (sym)", insn);
+ return ret;
+}
+
+static int validate_section(struct objtool_file *file, struct section *sec)
+{
+ struct insn_state state;
+ struct symbol *func;
+ int warnings = 0;
+
+ list_for_each_entry(func, &sec->symbol_list, list) {
+ if (func->type != STT_FUNC)
+ continue;
+
+ init_insn_state(&state, sec);
+ set_func_state(&state.cfi);
+
+ warnings += validate_symbol(file, sec, func, &state);
+ }
+
+ return warnings;
+}
+
+static int validate_vmlinux_functions(struct objtool_file *file)
+{
+ struct section *sec;
+ int warnings = 0;
+
+ sec = find_section_by_name(file->elf, ".noinstr.text");
+ if (sec) {
+ warnings += validate_section(file, sec);
+ warnings += validate_unwind_hints(file, sec);
+ }
+
+ sec = find_section_by_name(file->elf, ".entry.text");
+ if (sec) {
+ warnings += validate_section(file, sec);
+ warnings += validate_unwind_hints(file, sec);
+ }
+
+ return warnings;
+}
+
static int validate_functions(struct objtool_file *file)
{
struct section *sec;
- struct symbol *func;
- struct instruction *insn;
- struct insn_state state;
- int ret, warnings = 0;
-
- clear_insn_state(&state);
-
- state.cfa = initial_func_cfi.cfa;
- memcpy(&state.regs, &initial_func_cfi.regs,
- CFI_NUM_REGS * sizeof(struct cfi_reg));
- state.stack_size = initial_func_cfi.cfa.offset;
+ int warnings = 0;
for_each_sec(file, sec) {
- list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->type != STT_FUNC || func->pfunc != func)
- continue;
+ if (!(sec->sh.sh_flags & SHF_EXECINSTR))
+ continue;
- insn = find_insn(file, sec, func->offset);
- if (!insn || insn->ignore)
- continue;
-
- ret = validate_branch(file, insn, state);
- warnings += ret;
- }
+ warnings += validate_section(file, sec);
}
return warnings;
@@ -2177,7 +3574,7 @@
return 0;
for_each_insn(file, insn) {
- if (insn->visited || ignore_unreachable_insn(insn))
+ if (insn->visited || ignore_unreachable_insn(file, insn))
continue;
WARN_FUNC("unreachable instruction", insn->sec, insn->offset);
@@ -2187,95 +3584,112 @@
return 0;
}
-static void cleanup(struct objtool_file *file)
-{
- struct instruction *insn, *tmpinsn;
- struct alternative *alt, *tmpalt;
-
- list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) {
- list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) {
- list_del(&alt->list);
- free(alt);
- }
- list_del(&insn->list);
- hash_del(&insn->hash);
- free(insn);
- }
- elf_close(file->elf);
-}
-
-static struct objtool_file file;
-
-int check(const char *_objname, bool orc)
+int check(struct objtool_file *file)
{
int ret, warnings = 0;
- objname = _objname;
-
- file.elf = elf_open(objname, orc ? O_RDWR : O_RDONLY);
- if (!file.elf)
- return 1;
-
- INIT_LIST_HEAD(&file.insn_list);
- hash_init(file.insn_hash);
- file.whitelist = find_section_by_name(file.elf, ".discard.func_stack_frame_non_standard");
- file.c_file = find_section_by_name(file.elf, ".comment");
- file.ignore_unreachables = no_unreachable;
- file.hints = false;
-
arch_initial_func_cfi_state(&initial_func_cfi);
+ init_cfi_state(&init_cfi);
+ init_cfi_state(&func_cfi);
+ set_func_state(&func_cfi);
- ret = decode_sections(&file);
+ if (!cfi_hash_alloc())
+ goto out;
+
+ cfi_hash_add(&init_cfi);
+ cfi_hash_add(&func_cfi);
+
+ ret = decode_sections(file);
if (ret < 0)
goto out;
+
warnings += ret;
- if (list_empty(&file.insn_list))
+ if (list_empty(&file->insn_list))
goto out;
+ if (vmlinux && !validate_dup) {
+ ret = validate_vmlinux_functions(file);
+ if (ret < 0)
+ goto out;
+
+ warnings += ret;
+ goto out;
+ }
+
if (retpoline) {
- ret = validate_retpoline(&file);
+ ret = validate_retpoline(file);
if (ret < 0)
return ret;
warnings += ret;
}
- ret = validate_functions(&file);
+ ret = validate_functions(file);
if (ret < 0)
goto out;
warnings += ret;
- ret = validate_unwind_hints(&file);
+ ret = validate_unwind_hints(file, NULL);
if (ret < 0)
goto out;
warnings += ret;
+
+ if (unret) {
+ /*
+ * Must be after validate_branch() and friends, it plays
+ * further games with insn->visited.
+ */
+ ret = validate_unret(file);
+ if (ret < 0)
+ return ret;
+ warnings += ret;
+ }
if (!warnings) {
- ret = validate_reachable_instructions(&file);
+ ret = validate_reachable_instructions(file);
if (ret < 0)
goto out;
warnings += ret;
}
- if (orc) {
- ret = create_orc(&file);
- if (ret < 0)
- goto out;
+ ret = create_static_call_sections(file);
+ if (ret < 0)
+ goto out;
+ warnings += ret;
- ret = create_orc_sections(&file);
+ if (mcount) {
+ ret = create_mcount_loc_sections(file);
if (ret < 0)
goto out;
+ warnings += ret;
+ }
- ret = elf_write(file.elf);
+ if (retpoline) {
+ ret = create_retpoline_sites_sections(file);
if (ret < 0)
goto out;
+ warnings += ret;
+ }
+
+ if (rethunk) {
+ ret = create_return_sites_sections(file);
+ if (ret < 0)
+ goto out;
+ warnings += ret;
+ }
+
+ if (stats) {
+ printf("nr_insns_visited: %ld\n", nr_insns_visited);
+ printf("nr_cfi: %ld\n", nr_cfi);
+ printf("nr_cfi_reused: %ld\n", nr_cfi_reused);
+ printf("nr_cfi_cache: %ld\n", nr_cfi_cache);
}
out:
- cleanup(&file);
-
- /* ignore warnings for now until we get all the code cleaned up */
- if (ret || warnings)
- return 0;
+ /*
+ * For now, don't fail the kernel build on fatal warnings. These
+ * errors are still fairly common due to the growing matrix of
+ * supported toolchains and their recent pace of change.
+ */
return 0;
}
--
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