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