/*
|
* Copyright (c) 2016 GitHub, Inc.
|
*
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
* you may not use this file except in compliance with the License.
|
* You may obtain a copy of the License at
|
*
|
* http://www.apache.org/licenses/LICENSE-2.0
|
*
|
* Unless required by applicable law or agreed to in writing, software
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
* See the License for the specific language governing permissions and
|
* limitations under the License.
|
*/
|
|
#include <sys/types.h>
|
#include <sys/stat.h>
|
#include <sys/mman.h>
|
#include <ctype.h>
|
#include <fcntl.h>
|
#include <limits.h>
|
#include <math.h>
|
#include <stdbool.h>
|
#include <stdint.h>
|
#include <stdio.h>
|
#include <stdlib.h>
|
#include <string.h>
|
#include <unistd.h>
|
|
#include "bcc_perf_map.h"
|
#include "bcc_proc.h"
|
#include "bcc_elf.h"
|
|
#ifdef __x86_64__
|
// https://www.kernel.org/doc/Documentation/x86/x86_64/mm.txt
|
const unsigned long long kernelAddrSpace = 0x00ffffffffffffff;
|
#else
|
const unsigned long long kernelAddrSpace = 0x0;
|
#endif
|
|
char *bcc_procutils_which(const char *binpath) {
|
char buffer[4096];
|
const char *PATH;
|
|
if (strchr(binpath, '/'))
|
return bcc_elf_is_exe(binpath) ? strdup(binpath) : 0;
|
|
if (!(PATH = getenv("PATH")))
|
return 0;
|
|
while (PATH) {
|
const char *next = strchr(PATH, ':') ?: strchr(PATH, '\0');
|
const size_t path_len = next - PATH;
|
|
if (path_len) {
|
int ret = snprintf(buffer, sizeof(buffer), "%.*s/%s",
|
(int)path_len, PATH, binpath);
|
if (ret < 0 || ret >= sizeof(buffer))
|
return 0;
|
|
if (bcc_elf_is_exe(buffer))
|
return strdup(buffer);
|
}
|
|
PATH = *next ? (next + 1) : 0;
|
}
|
|
return 0;
|
}
|
|
#define STARTS_WITH(mapname, prefix) (!strncmp(mapname, prefix, sizeof(prefix)-1))
|
|
int bcc_mapping_is_file_backed(const char *mapname) {
|
return mapname[0] && !(
|
STARTS_WITH(mapname, "//anon") ||
|
STARTS_WITH(mapname, "/dev/zero") ||
|
STARTS_WITH(mapname, "/anon_hugepage") ||
|
STARTS_WITH(mapname, "[stack") ||
|
STARTS_WITH(mapname, "/SYSV") ||
|
STARTS_WITH(mapname, "[heap]") ||
|
STARTS_WITH(mapname, "[vsyscall]"));
|
}
|
|
int bcc_procutils_each_module(int pid, bcc_procutils_modulecb callback,
|
void *payload) {
|
char procmap_filename[128];
|
FILE *procmap;
|
snprintf(procmap_filename, sizeof(procmap_filename), "/proc/%ld/maps",
|
(long)pid);
|
procmap = fopen(procmap_filename, "r");
|
if (!procmap)
|
return -1;
|
|
char buf[PATH_MAX + 1], perm[5], dev[8];
|
char *name;
|
uint64_t begin, end, inode;
|
unsigned long long offset;
|
while (true) {
|
buf[0] = '\0';
|
// From fs/proc/task_mmu.c:show_map_vma
|
if (fscanf(procmap, "%lx-%lx %s %llx %s %lu%[^\n]", &begin, &end, perm,
|
&offset, dev, &inode, buf) != 7)
|
break;
|
|
if (perm[2] != 'x')
|
continue;
|
|
name = buf;
|
while (isspace(*name))
|
name++;
|
if (!bcc_mapping_is_file_backed(name))
|
continue;
|
|
if (callback(name, begin, end, (uint64_t)offset, true, payload) < 0)
|
break;
|
}
|
|
fclose(procmap);
|
|
// Address mapping for the entire address space maybe in /tmp/perf-<PID>.map
|
// This will be used if symbols aren't resolved in an earlier mapping.
|
char map_path[4096];
|
// Try perf-<PID>.map path with process's mount namespace, chroot and NSPID,
|
// in case it is generated by the process itself.
|
if (bcc_perf_map_path(map_path, sizeof(map_path), pid))
|
if (callback(map_path, 0, -1, 0, true, payload) < 0)
|
return 0;
|
// Try perf-<PID>.map path with global root and PID, in case it is generated
|
// by other Process. Avoid checking mount namespace for this.
|
int res = snprintf(map_path, 4096, "/tmp/perf-%d.map", pid);
|
if (res > 0 && res < 4096)
|
if (callback(map_path, 0, -1, 0, false, payload) < 0)
|
return 0;
|
|
return 0;
|
}
|
|
int bcc_procutils_each_ksym(bcc_procutils_ksymcb callback, void *payload) {
|
char line[2048];
|
char *symname, *endsym;
|
FILE *kallsyms;
|
unsigned long long addr;
|
|
/* root is needed to list ksym addresses */
|
if (geteuid() != 0)
|
return -1;
|
|
kallsyms = fopen("/proc/kallsyms", "r");
|
if (!kallsyms)
|
return -1;
|
|
while (fgets(line, sizeof(line), kallsyms)) {
|
addr = strtoull(line, &symname, 16);
|
if (addr == 0 || addr == ULLONG_MAX)
|
continue;
|
if (addr < kernelAddrSpace)
|
continue;
|
|
symname++;
|
// Ignore data symbols
|
if (*symname == 'b' || *symname == 'B' || *symname == 'd' ||
|
*symname == 'D' || *symname == 'r' || *symname =='R')
|
continue;
|
|
endsym = (symname = symname + 2);
|
while (*endsym && !isspace(*endsym)) endsym++;
|
*endsym = '\0';
|
|
callback(symname, addr, payload);
|
}
|
|
fclose(kallsyms);
|
return 0;
|
}
|
|
#define CACHE1_HEADER "ld.so-1.7.0"
|
#define CACHE1_HEADER_LEN (sizeof(CACHE1_HEADER) - 1)
|
|
#define CACHE2_HEADER "glibc-ld.so.cache"
|
#define CACHE2_HEADER_LEN (sizeof(CACHE2_HEADER) - 1)
|
#define CACHE2_VERSION "1.1"
|
|
struct ld_cache1_entry {
|
int32_t flags;
|
uint32_t key;
|
uint32_t value;
|
};
|
|
struct ld_cache1 {
|
char header[CACHE1_HEADER_LEN];
|
uint32_t entry_count;
|
struct ld_cache1_entry entries[0];
|
};
|
|
struct ld_cache2_entry {
|
int32_t flags;
|
uint32_t key;
|
uint32_t value;
|
uint32_t pad1_;
|
uint64_t pad2_;
|
};
|
|
struct ld_cache2 {
|
char header[CACHE2_HEADER_LEN];
|
char version[3];
|
uint32_t entry_count;
|
uint32_t string_table_len;
|
uint32_t pad_[5];
|
struct ld_cache2_entry entries[0];
|
};
|
|
static int lib_cache_count;
|
static struct ld_lib {
|
char *libname;
|
char *path;
|
int flags;
|
} * lib_cache;
|
|
static int read_cache1(const char *ld_map) {
|
struct ld_cache1 *ldcache = (struct ld_cache1 *)ld_map;
|
const char *ldstrings =
|
(const char *)(ldcache->entries + ldcache->entry_count);
|
uint32_t i;
|
|
lib_cache =
|
(struct ld_lib *)malloc(ldcache->entry_count * sizeof(struct ld_lib));
|
lib_cache_count = (int)ldcache->entry_count;
|
|
for (i = 0; i < ldcache->entry_count; ++i) {
|
const char *key = ldstrings + ldcache->entries[i].key;
|
const char *val = ldstrings + ldcache->entries[i].value;
|
const int flags = ldcache->entries[i].flags;
|
|
lib_cache[i].libname = strdup(key);
|
lib_cache[i].path = strdup(val);
|
lib_cache[i].flags = flags;
|
}
|
return 0;
|
}
|
|
static int read_cache2(const char *ld_map) {
|
struct ld_cache2 *ldcache = (struct ld_cache2 *)ld_map;
|
uint32_t i;
|
|
if (memcmp(ld_map, CACHE2_HEADER, CACHE2_HEADER_LEN))
|
return -1;
|
|
lib_cache =
|
(struct ld_lib *)malloc(ldcache->entry_count * sizeof(struct ld_lib));
|
lib_cache_count = (int)ldcache->entry_count;
|
|
for (i = 0; i < ldcache->entry_count; ++i) {
|
const char *key = ld_map + ldcache->entries[i].key;
|
const char *val = ld_map + ldcache->entries[i].value;
|
const int flags = ldcache->entries[i].flags;
|
|
lib_cache[i].libname = strdup(key);
|
lib_cache[i].path = strdup(val);
|
lib_cache[i].flags = flags;
|
}
|
return 0;
|
}
|
|
static int load_ld_cache(const char *cache_path) {
|
struct stat st;
|
size_t ld_size;
|
const char *ld_map;
|
int ret, fd = open(cache_path, O_RDONLY);
|
|
if (fd < 0)
|
return -1;
|
|
if (fstat(fd, &st) < 0 || st.st_size < sizeof(struct ld_cache1)) {
|
close(fd);
|
return -1;
|
}
|
|
ld_size = st.st_size;
|
ld_map = (const char *)mmap(NULL, ld_size, PROT_READ, MAP_PRIVATE, fd, 0);
|
if (ld_map == MAP_FAILED) {
|
close(fd);
|
return -1;
|
}
|
|
if (memcmp(ld_map, CACHE1_HEADER, CACHE1_HEADER_LEN) == 0) {
|
const struct ld_cache1 *cache1 = (struct ld_cache1 *)ld_map;
|
size_t cache1_len = sizeof(struct ld_cache1) +
|
(cache1->entry_count * sizeof(struct ld_cache1_entry));
|
cache1_len = (cache1_len + 0x7) & ~0x7ULL;
|
|
if (ld_size > (cache1_len + sizeof(struct ld_cache2)))
|
ret = read_cache2(ld_map + cache1_len);
|
else
|
ret = read_cache1(ld_map);
|
} else {
|
ret = read_cache2(ld_map);
|
}
|
|
munmap((void *)ld_map, ld_size);
|
close(fd);
|
return ret;
|
}
|
|
#define LD_SO_CACHE "/etc/ld.so.cache"
|
#define FLAG_TYPE_MASK 0x00ff
|
#define TYPE_ELF_LIBC6 0x0003
|
#define FLAG_ABI_MASK 0xff00
|
#define ABI_SPARC_LIB64 0x0100
|
#define ABI_IA64_LIB64 0x0200
|
#define ABI_X8664_LIB64 0x0300
|
#define ABI_S390_LIB64 0x0400
|
#define ABI_POWERPC_LIB64 0x0500
|
#define ABI_AARCH64_LIB64 0x0a00
|
|
static bool match_so_flags(int flags) {
|
if ((flags & FLAG_TYPE_MASK) != TYPE_ELF_LIBC6)
|
return false;
|
|
switch (flags & FLAG_ABI_MASK) {
|
case ABI_SPARC_LIB64:
|
case ABI_IA64_LIB64:
|
case ABI_X8664_LIB64:
|
case ABI_S390_LIB64:
|
case ABI_POWERPC_LIB64:
|
case ABI_AARCH64_LIB64:
|
return (sizeof(void *) == 8);
|
}
|
|
return sizeof(void *) == 4;
|
}
|
|
static bool which_so_in_process(const char* libname, int pid, char* libpath) {
|
int ret, found = false;
|
char endline[4096], *mapname = NULL, *newline;
|
char mappings_file[128];
|
const size_t search_len = strlen(libname) + strlen("/lib.");
|
char search1[search_len + 1];
|
char search2[search_len + 1];
|
|
snprintf(mappings_file, sizeof(mappings_file), "/proc/%ld/maps", (long)pid);
|
FILE *fp = fopen(mappings_file, "r");
|
if (!fp)
|
return NULL;
|
|
snprintf(search1, search_len + 1, "/lib%s.", libname);
|
snprintf(search2, search_len + 1, "/lib%s-", libname);
|
|
do {
|
ret = fscanf(fp, "%*x-%*x %*s %*x %*s %*d");
|
if (!fgets(endline, sizeof(endline), fp))
|
break;
|
|
mapname = endline;
|
newline = strchr(endline, '\n');
|
if (newline)
|
newline[0] = '\0';
|
|
while (isspace(mapname[0])) mapname++;
|
|
if (strstr(mapname, ".so") && (strstr(mapname, search1) ||
|
strstr(mapname, search2))) {
|
found = true;
|
memcpy(libpath, mapname, strlen(mapname) + 1);
|
break;
|
}
|
} while (ret != EOF);
|
|
fclose(fp);
|
return found;
|
}
|
|
char *bcc_procutils_which_so(const char *libname, int pid) {
|
const size_t soname_len = strlen(libname) + strlen("lib.so");
|
char soname[soname_len + 1];
|
char libpath[4096];
|
int i;
|
|
if (strchr(libname, '/'))
|
return strdup(libname);
|
|
if (pid && which_so_in_process(libname, pid, libpath))
|
return strdup(libpath);
|
|
if (lib_cache_count < 0)
|
return NULL;
|
|
if (!lib_cache_count && load_ld_cache(LD_SO_CACHE) < 0) {
|
lib_cache_count = -1;
|
return NULL;
|
}
|
|
snprintf(soname, soname_len + 1, "lib%s.so", libname);
|
|
for (i = 0; i < lib_cache_count; ++i) {
|
if (!strncmp(lib_cache[i].libname, soname, soname_len) &&
|
match_so_flags(lib_cache[i].flags)) {
|
return strdup(lib_cache[i].path);
|
}
|
}
|
return NULL;
|
}
|
|
void bcc_procutils_free(const char *ptr) {
|
free((void *)ptr);
|
}
|
|
/* Detects the following languages + C. */
|
const char *languages[] = {"java", "node", "perl", "php", "python", "ruby"};
|
const char *language_c = "c";
|
const int nb_languages = 6;
|
|
const char *bcc_procutils_language(int pid) {
|
char procfilename[24], line[4096], pathname[32], *str;
|
FILE *procfile;
|
int i, ret;
|
|
/* Look for clues in the absolute path to the executable. */
|
snprintf(procfilename, sizeof(procfilename), "/proc/%ld/exe", (long)pid);
|
if (realpath(procfilename, line)) {
|
for (i = 0; i < nb_languages; i++)
|
if (strstr(line, languages[i]))
|
return languages[i];
|
}
|
|
|
snprintf(procfilename, sizeof(procfilename), "/proc/%ld/maps", (long)pid);
|
procfile = fopen(procfilename, "r");
|
if (!procfile)
|
return NULL;
|
|
/* Look for clues in memory mappings. */
|
bool libc = false;
|
do {
|
char perm[8], dev[8];
|
long long begin, end, size, inode;
|
ret = fscanf(procfile, "%llx-%llx %s %llx %s %lld", &begin, &end, perm,
|
&size, dev, &inode);
|
if (!fgets(line, sizeof(line), procfile))
|
break;
|
if (ret == 6) {
|
char *mapname = line;
|
char *newline = strchr(line, '\n');
|
if (newline)
|
newline[0] = '\0';
|
while (isspace(mapname[0])) mapname++;
|
for (i = 0; i < nb_languages; i++) {
|
snprintf(pathname, sizeof(pathname), "/lib%s", languages[i]);
|
if (strstr(mapname, pathname)) {
|
fclose(procfile);
|
return languages[i];
|
}
|
if ((str = strstr(mapname, "libc")) &&
|
(str[4] == '-' || str[4] == '.'))
|
libc = true;
|
}
|
}
|
} while (ret && ret != EOF);
|
|
fclose(procfile);
|
|
/* Return C as the language if libc was found and nothing else. */
|
return libc ? language_c : NULL;
|
}
|
