1 #include "symbol.h" 2 #include "util.h" 3 4 #include <errno.h> 5 #include <stdio.h> 6 #include <fcntl.h> 7 #include <string.h> 8 #include <byteswap.h> 9 #include <sys/stat.h> 10 11 12 static bool check_need_swap(int file_endian) 13 { 14 const int data = 1; 15 u8 *check = (u8 *)&data; 16 int host_endian; 17 18 if (check[0] == 1) 19 host_endian = ELFDATA2LSB; 20 else 21 host_endian = ELFDATA2MSB; 22 23 return host_endian != file_endian; 24 } 25 26 #define NOTE_ALIGN(sz) (((sz) + 3) & ~3) 27 28 #define NT_GNU_BUILD_ID 3 29 30 static int read_build_id(void *note_data, size_t note_len, void *bf, 31 size_t size, bool need_swap) 32 { 33 struct { 34 u32 n_namesz; 35 u32 n_descsz; 36 u32 n_type; 37 } *nhdr; 38 void *ptr; 39 40 ptr = note_data; 41 while (ptr < (note_data + note_len)) { 42 const char *name; 43 size_t namesz, descsz; 44 45 nhdr = ptr; 46 if (need_swap) { 47 nhdr->n_namesz = bswap_32(nhdr->n_namesz); 48 nhdr->n_descsz = bswap_32(nhdr->n_descsz); 49 nhdr->n_type = bswap_32(nhdr->n_type); 50 } 51 52 namesz = NOTE_ALIGN(nhdr->n_namesz); 53 descsz = NOTE_ALIGN(nhdr->n_descsz); 54 55 ptr += sizeof(*nhdr); 56 name = ptr; 57 ptr += namesz; 58 if (nhdr->n_type == NT_GNU_BUILD_ID && 59 nhdr->n_namesz == sizeof("GNU")) { 60 if (memcmp(name, "GNU", sizeof("GNU")) == 0) { 61 size_t sz = min(size, descsz); 62 memcpy(bf, ptr, sz); 63 memset(bf + sz, 0, size - sz); 64 return 0; 65 } 66 } 67 ptr += descsz; 68 } 69 70 return -1; 71 } 72 73 int filename__read_debuglink(const char *filename __maybe_unused, 74 char *debuglink __maybe_unused, 75 size_t size __maybe_unused) 76 { 77 return -1; 78 } 79 80 /* 81 * Just try PT_NOTE header otherwise fails 82 */ 83 int filename__read_build_id(const char *filename, void *bf, size_t size) 84 { 85 FILE *fp; 86 int ret = -1; 87 bool need_swap = false; 88 u8 e_ident[EI_NIDENT]; 89 size_t buf_size; 90 void *buf; 91 int i; 92 93 fp = fopen(filename, "r"); 94 if (fp == NULL) 95 return -1; 96 97 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1) 98 goto out; 99 100 if (memcmp(e_ident, ELFMAG, SELFMAG) || 101 e_ident[EI_VERSION] != EV_CURRENT) 102 goto out; 103 104 need_swap = check_need_swap(e_ident[EI_DATA]); 105 106 /* for simplicity */ 107 fseek(fp, 0, SEEK_SET); 108 109 if (e_ident[EI_CLASS] == ELFCLASS32) { 110 Elf32_Ehdr ehdr; 111 Elf32_Phdr *phdr; 112 113 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) 114 goto out; 115 116 if (need_swap) { 117 ehdr.e_phoff = bswap_32(ehdr.e_phoff); 118 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); 119 ehdr.e_phnum = bswap_16(ehdr.e_phnum); 120 } 121 122 buf_size = ehdr.e_phentsize * ehdr.e_phnum; 123 buf = malloc(buf_size); 124 if (buf == NULL) 125 goto out; 126 127 fseek(fp, ehdr.e_phoff, SEEK_SET); 128 if (fread(buf, buf_size, 1, fp) != 1) 129 goto out_free; 130 131 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { 132 void *tmp; 133 long offset; 134 135 if (need_swap) { 136 phdr->p_type = bswap_32(phdr->p_type); 137 phdr->p_offset = bswap_32(phdr->p_offset); 138 phdr->p_filesz = bswap_32(phdr->p_filesz); 139 } 140 141 if (phdr->p_type != PT_NOTE) 142 continue; 143 144 buf_size = phdr->p_filesz; 145 offset = phdr->p_offset; 146 tmp = realloc(buf, buf_size); 147 if (tmp == NULL) 148 goto out_free; 149 150 buf = tmp; 151 fseek(fp, offset, SEEK_SET); 152 if (fread(buf, buf_size, 1, fp) != 1) 153 goto out_free; 154 155 ret = read_build_id(buf, buf_size, bf, size, need_swap); 156 if (ret == 0) 157 ret = size; 158 break; 159 } 160 } else { 161 Elf64_Ehdr ehdr; 162 Elf64_Phdr *phdr; 163 164 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) 165 goto out; 166 167 if (need_swap) { 168 ehdr.e_phoff = bswap_64(ehdr.e_phoff); 169 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); 170 ehdr.e_phnum = bswap_16(ehdr.e_phnum); 171 } 172 173 buf_size = ehdr.e_phentsize * ehdr.e_phnum; 174 buf = malloc(buf_size); 175 if (buf == NULL) 176 goto out; 177 178 fseek(fp, ehdr.e_phoff, SEEK_SET); 179 if (fread(buf, buf_size, 1, fp) != 1) 180 goto out_free; 181 182 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { 183 void *tmp; 184 long offset; 185 186 if (need_swap) { 187 phdr->p_type = bswap_32(phdr->p_type); 188 phdr->p_offset = bswap_64(phdr->p_offset); 189 phdr->p_filesz = bswap_64(phdr->p_filesz); 190 } 191 192 if (phdr->p_type != PT_NOTE) 193 continue; 194 195 buf_size = phdr->p_filesz; 196 offset = phdr->p_offset; 197 tmp = realloc(buf, buf_size); 198 if (tmp == NULL) 199 goto out_free; 200 201 buf = tmp; 202 fseek(fp, offset, SEEK_SET); 203 if (fread(buf, buf_size, 1, fp) != 1) 204 goto out_free; 205 206 ret = read_build_id(buf, buf_size, bf, size, need_swap); 207 if (ret == 0) 208 ret = size; 209 break; 210 } 211 } 212 out_free: 213 free(buf); 214 out: 215 fclose(fp); 216 return ret; 217 } 218 219 int sysfs__read_build_id(const char *filename, void *build_id, size_t size) 220 { 221 int fd; 222 int ret = -1; 223 struct stat stbuf; 224 size_t buf_size; 225 void *buf; 226 227 fd = open(filename, O_RDONLY); 228 if (fd < 0) 229 return -1; 230 231 if (fstat(fd, &stbuf) < 0) 232 goto out; 233 234 buf_size = stbuf.st_size; 235 buf = malloc(buf_size); 236 if (buf == NULL) 237 goto out; 238 239 if (read(fd, buf, buf_size) != (ssize_t) buf_size) 240 goto out_free; 241 242 ret = read_build_id(buf, buf_size, build_id, size, false); 243 out_free: 244 free(buf); 245 out: 246 close(fd); 247 return ret; 248 } 249 250 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, 251 enum dso_binary_type type) 252 { 253 int fd = open(name, O_RDONLY); 254 if (fd < 0) 255 goto out_errno; 256 257 ss->name = strdup(name); 258 if (!ss->name) 259 goto out_close; 260 261 ss->fd = fd; 262 ss->type = type; 263 264 return 0; 265 out_close: 266 close(fd); 267 out_errno: 268 dso->load_errno = errno; 269 return -1; 270 } 271 272 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused) 273 { 274 /* Assume all sym sources could be a runtime image. */ 275 return true; 276 } 277 278 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused) 279 { 280 return false; 281 } 282 283 void symsrc__destroy(struct symsrc *ss) 284 { 285 zfree(&ss->name); 286 close(ss->fd); 287 } 288 289 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused, 290 struct symsrc *ss __maybe_unused, 291 struct map *map __maybe_unused) 292 { 293 return 0; 294 } 295 296 static int fd__is_64_bit(int fd) 297 { 298 u8 e_ident[EI_NIDENT]; 299 300 if (lseek(fd, 0, SEEK_SET)) 301 return -1; 302 303 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident)) 304 return -1; 305 306 if (memcmp(e_ident, ELFMAG, SELFMAG) || 307 e_ident[EI_VERSION] != EV_CURRENT) 308 return -1; 309 310 return e_ident[EI_CLASS] == ELFCLASS64; 311 } 312 313 enum dso_type dso__type_fd(int fd) 314 { 315 Elf64_Ehdr ehdr; 316 int ret; 317 318 ret = fd__is_64_bit(fd); 319 if (ret < 0) 320 return DSO__TYPE_UNKNOWN; 321 322 if (ret) 323 return DSO__TYPE_64BIT; 324 325 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr)) 326 return DSO__TYPE_UNKNOWN; 327 328 if (ehdr.e_machine == EM_X86_64) 329 return DSO__TYPE_X32BIT; 330 331 return DSO__TYPE_32BIT; 332 } 333 334 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused, 335 struct symsrc *ss, 336 struct symsrc *runtime_ss __maybe_unused, 337 int kmodule __maybe_unused) 338 { 339 unsigned char build_id[BUILD_ID_SIZE]; 340 int ret; 341 342 ret = fd__is_64_bit(ss->fd); 343 if (ret >= 0) 344 dso->is_64_bit = ret; 345 346 if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) { 347 dso__set_build_id(dso, build_id); 348 } 349 return 0; 350 } 351 352 int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused, 353 mapfn_t mapfn __maybe_unused, void *data __maybe_unused, 354 bool *is_64_bit __maybe_unused) 355 { 356 return -1; 357 } 358 359 int kcore_extract__create(struct kcore_extract *kce __maybe_unused) 360 { 361 return -1; 362 } 363 364 void kcore_extract__delete(struct kcore_extract *kce __maybe_unused) 365 { 366 } 367 368 int kcore_copy(const char *from_dir __maybe_unused, 369 const char *to_dir __maybe_unused) 370 { 371 return -1; 372 } 373 374 void symbol__elf_init(void) 375 { 376 } 377 378 char *dso__demangle_sym(struct dso *dso __maybe_unused, 379 int kmodule __maybe_unused, 380 char *elf_name __maybe_unused) 381 { 382 return NULL; 383 } 384