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 16 static 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 else 25 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 3 33 34 static 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 79 int 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 fails 88 */ 89 int 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 } 220 out_free: 221 free(buf); 222 out: 223 fclose(fp); 224 return ret; 225 } 226 227 int 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); 251 out_free: 252 free(buf); 253 out: 254 close(fd); 255 return ret; 256 } 257 258 int 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; 273 out_close: 274 close(fd); 275 out_errno: 276 RC_CHK_ACCESS(dso)->load_errno = errno; 277 return -1; 278 } 279 280 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused) 281 { 282 /* Assume all sym sources could be a runtime image. */ 283 return true; 284 } 285 286 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused) 287 { 288 return false; 289 } 290 291 void symsrc__destroy(struct symsrc *ss) 292 { 293 zfree(&ss->name); 294 close(ss->fd); 295 } 296 297 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused, 298 struct symsrc *ss __maybe_unused) 299 { 300 return 0; 301 } 302 303 static 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 } 319 320 enum 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 } 340 341 int 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 } 357 358 int 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 } 364 365 int kcore_extract__create(struct kcore_extract *kce __maybe_unused) 366 { 367 return -1; 368 } 369 370 void kcore_extract__delete(struct kcore_extract *kce __maybe_unused) 371 { 372 } 373 374 int kcore_copy(const char *from_dir __maybe_unused, 375 const char *to_dir __maybe_unused) 376 { 377 return -1; 378 } 379 380 void symbol__elf_init(void) 381 { 382 } 383 384 char *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 } 390 391 bool filename__has_section(const char *filename __maybe_unused, const char *sec __maybe_unused) 392 { 393 return false; 394 } 395