| /* |
| * 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", "python", "ruby", "php", "node"}; |
| const char *language_c = "c"; |
| const int nb_languages = 5; |
| |
| 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)) |
| 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; |
| } |