395 lines · c
1#include "dso.h"2#include "symbol.h"3#include "symsrc.h"4 5#include <errno.h>6#include <unistd.h>7#include <stdio.h>8#include <fcntl.h>9#include <string.h>10#include <stdlib.h>11#include <byteswap.h>12#include <sys/stat.h>13#include <linux/zalloc.h>14#include <internal/lib.h>15 16static bool check_need_swap(int file_endian)17{18 const int data = 1;19 u8 *check = (u8 *)&data;20 int host_endian;21 22 if (check[0] == 1)23 host_endian = ELFDATA2LSB;24 else25 host_endian = ELFDATA2MSB;26 27 return host_endian != file_endian;28}29 30#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)31 32#define NT_GNU_BUILD_ID 333 34static int read_build_id(void *note_data, size_t note_len, struct build_id *bid,35 bool need_swap)36{37 size_t size = sizeof(bid->data);38 struct {39 u32 n_namesz;40 u32 n_descsz;41 u32 n_type;42 } *nhdr;43 void *ptr;44 45 ptr = note_data;46 while (ptr < (note_data + note_len)) {47 const char *name;48 size_t namesz, descsz;49 50 nhdr = ptr;51 if (need_swap) {52 nhdr->n_namesz = bswap_32(nhdr->n_namesz);53 nhdr->n_descsz = bswap_32(nhdr->n_descsz);54 nhdr->n_type = bswap_32(nhdr->n_type);55 }56 57 namesz = NOTE_ALIGN(nhdr->n_namesz);58 descsz = NOTE_ALIGN(nhdr->n_descsz);59 60 ptr += sizeof(*nhdr);61 name = ptr;62 ptr += namesz;63 if (nhdr->n_type == NT_GNU_BUILD_ID &&64 nhdr->n_namesz == sizeof("GNU")) {65 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {66 size_t sz = min(size, descsz);67 memcpy(bid->data, ptr, sz);68 memset(bid->data + sz, 0, size - sz);69 bid->size = sz;70 return 0;71 }72 }73 ptr += descsz;74 }75 76 return -1;77}78 79int filename__read_debuglink(const char *filename __maybe_unused,80 char *debuglink __maybe_unused,81 size_t size __maybe_unused)82{83 return -1;84}85 86/*87 * Just try PT_NOTE header otherwise fails88 */89int filename__read_build_id(const char *filename, struct build_id *bid)90{91 FILE *fp;92 int ret = -1;93 bool need_swap = false;94 u8 e_ident[EI_NIDENT];95 size_t buf_size;96 void *buf;97 int i;98 99 fp = fopen(filename, "r");100 if (fp == NULL)101 return -1;102 103 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)104 goto out;105 106 if (memcmp(e_ident, ELFMAG, SELFMAG) ||107 e_ident[EI_VERSION] != EV_CURRENT)108 goto out;109 110 need_swap = check_need_swap(e_ident[EI_DATA]);111 112 /* for simplicity */113 fseek(fp, 0, SEEK_SET);114 115 if (e_ident[EI_CLASS] == ELFCLASS32) {116 Elf32_Ehdr ehdr;117 Elf32_Phdr *phdr;118 119 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)120 goto out;121 122 if (need_swap) {123 ehdr.e_phoff = bswap_32(ehdr.e_phoff);124 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);125 ehdr.e_phnum = bswap_16(ehdr.e_phnum);126 }127 128 buf_size = ehdr.e_phentsize * ehdr.e_phnum;129 buf = malloc(buf_size);130 if (buf == NULL)131 goto out;132 133 fseek(fp, ehdr.e_phoff, SEEK_SET);134 if (fread(buf, buf_size, 1, fp) != 1)135 goto out_free;136 137 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {138 void *tmp;139 long offset;140 141 if (need_swap) {142 phdr->p_type = bswap_32(phdr->p_type);143 phdr->p_offset = bswap_32(phdr->p_offset);144 phdr->p_filesz = bswap_32(phdr->p_filesz);145 }146 147 if (phdr->p_type != PT_NOTE)148 continue;149 150 buf_size = phdr->p_filesz;151 offset = phdr->p_offset;152 tmp = realloc(buf, buf_size);153 if (tmp == NULL)154 goto out_free;155 156 buf = tmp;157 fseek(fp, offset, SEEK_SET);158 if (fread(buf, buf_size, 1, fp) != 1)159 goto out_free;160 161 ret = read_build_id(buf, buf_size, bid, need_swap);162 if (ret == 0) {163 ret = bid->size;164 break;165 }166 }167 } else {168 Elf64_Ehdr ehdr;169 Elf64_Phdr *phdr;170 171 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)172 goto out;173 174 if (need_swap) {175 ehdr.e_phoff = bswap_64(ehdr.e_phoff);176 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);177 ehdr.e_phnum = bswap_16(ehdr.e_phnum);178 }179 180 buf_size = ehdr.e_phentsize * ehdr.e_phnum;181 buf = malloc(buf_size);182 if (buf == NULL)183 goto out;184 185 fseek(fp, ehdr.e_phoff, SEEK_SET);186 if (fread(buf, buf_size, 1, fp) != 1)187 goto out_free;188 189 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {190 void *tmp;191 long offset;192 193 if (need_swap) {194 phdr->p_type = bswap_32(phdr->p_type);195 phdr->p_offset = bswap_64(phdr->p_offset);196 phdr->p_filesz = bswap_64(phdr->p_filesz);197 }198 199 if (phdr->p_type != PT_NOTE)200 continue;201 202 buf_size = phdr->p_filesz;203 offset = phdr->p_offset;204 tmp = realloc(buf, buf_size);205 if (tmp == NULL)206 goto out_free;207 208 buf = tmp;209 fseek(fp, offset, SEEK_SET);210 if (fread(buf, buf_size, 1, fp) != 1)211 goto out_free;212 213 ret = read_build_id(buf, buf_size, bid, need_swap);214 if (ret == 0) {215 ret = bid->size;216 break;217 }218 }219 }220out_free:221 free(buf);222out:223 fclose(fp);224 return ret;225}226 227int sysfs__read_build_id(const char *filename, struct build_id *bid)228{229 int fd;230 int ret = -1;231 struct stat stbuf;232 size_t buf_size;233 void *buf;234 235 fd = open(filename, O_RDONLY);236 if (fd < 0)237 return -1;238 239 if (fstat(fd, &stbuf) < 0)240 goto out;241 242 buf_size = stbuf.st_size;243 buf = malloc(buf_size);244 if (buf == NULL)245 goto out;246 247 if (read(fd, buf, buf_size) != (ssize_t) buf_size)248 goto out_free;249 250 ret = read_build_id(buf, buf_size, bid, false);251out_free:252 free(buf);253out:254 close(fd);255 return ret;256}257 258int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,259 enum dso_binary_type type)260{261 int fd = open(name, O_RDONLY);262 if (fd < 0)263 goto out_errno;264 265 ss->name = strdup(name);266 if (!ss->name)267 goto out_close;268 269 ss->fd = fd;270 ss->type = type;271 272 return 0;273out_close:274 close(fd);275out_errno:276 RC_CHK_ACCESS(dso)->load_errno = errno;277 return -1;278}279 280bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)281{282 /* Assume all sym sources could be a runtime image. */283 return true;284}285 286bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)287{288 return false;289}290 291void symsrc__destroy(struct symsrc *ss)292{293 zfree(&ss->name);294 close(ss->fd);295}296 297int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,298 struct symsrc *ss __maybe_unused)299{300 return 0;301}302 303static int fd__is_64_bit(int fd)304{305 u8 e_ident[EI_NIDENT];306 307 if (lseek(fd, 0, SEEK_SET))308 return -1;309 310 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))311 return -1;312 313 if (memcmp(e_ident, ELFMAG, SELFMAG) ||314 e_ident[EI_VERSION] != EV_CURRENT)315 return -1;316 317 return e_ident[EI_CLASS] == ELFCLASS64;318}319 320enum dso_type dso__type_fd(int fd)321{322 Elf64_Ehdr ehdr;323 int ret;324 325 ret = fd__is_64_bit(fd);326 if (ret < 0)327 return DSO__TYPE_UNKNOWN;328 329 if (ret)330 return DSO__TYPE_64BIT;331 332 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))333 return DSO__TYPE_UNKNOWN;334 335 if (ehdr.e_machine == EM_X86_64)336 return DSO__TYPE_X32BIT;337 338 return DSO__TYPE_32BIT;339}340 341int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,342 struct symsrc *ss,343 struct symsrc *runtime_ss __maybe_unused,344 int kmodule __maybe_unused)345{346 struct build_id bid;347 int ret;348 349 ret = fd__is_64_bit(ss->fd);350 if (ret >= 0)351 RC_CHK_ACCESS(dso)->is_64_bit = ret;352 353 if (filename__read_build_id(ss->name, &bid) > 0)354 dso__set_build_id(dso, &bid);355 return 0;356}357 358int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,359 mapfn_t mapfn __maybe_unused, void *data __maybe_unused,360 bool *is_64_bit __maybe_unused)361{362 return -1;363}364 365int kcore_extract__create(struct kcore_extract *kce __maybe_unused)366{367 return -1;368}369 370void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)371{372}373 374int kcore_copy(const char *from_dir __maybe_unused,375 const char *to_dir __maybe_unused)376{377 return -1;378}379 380void symbol__elf_init(void)381{382}383 384char *dso__demangle_sym(struct dso *dso __maybe_unused,385 int kmodule __maybe_unused,386 const char *elf_name __maybe_unused)387{388 return NULL;389}390 391bool filename__has_section(const char *filename __maybe_unused, const char *sec __maybe_unused)392{393 return false;394}395