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, void *bf, 35 size_t size, bool need_swap) 36 { 37 struct { 38 u32 n_namesz; 39 u32 n_descsz; 40 u32 n_type; 41 } *nhdr; 42 void *ptr; 43 44 ptr = note_data; 45 while (ptr < (note_data + note_len)) { 46 const char *name; 47 size_t namesz, descsz; 48 49 nhdr = ptr; 50 if (need_swap) { 51 nhdr->n_namesz = bswap_32(nhdr->n_namesz); 52 nhdr->n_descsz = bswap_32(nhdr->n_descsz); 53 nhdr->n_type = bswap_32(nhdr->n_type); 54 } 55 56 namesz = NOTE_ALIGN(nhdr->n_namesz); 57 descsz = NOTE_ALIGN(nhdr->n_descsz); 58 59 ptr += sizeof(*nhdr); 60 name = ptr; 61 ptr += namesz; 62 if (nhdr->n_type == NT_GNU_BUILD_ID && 63 nhdr->n_namesz == sizeof("GNU")) { 64 if (memcmp(name, "GNU", sizeof("GNU")) == 0) { 65 size_t sz = min(size, descsz); 66 memcpy(bf, ptr, sz); 67 memset(bf + sz, 0, size - sz); 68 return 0; 69 } 70 } 71 ptr += descsz; 72 } 73 74 return -1; 75 } 76 77 int filename__read_debuglink(const char *filename __maybe_unused, 78 char *debuglink __maybe_unused, 79 size_t size __maybe_unused) 80 { 81 return -1; 82 } 83 84 /* 85 * Just try PT_NOTE header otherwise fails 86 */ 87 int filename__read_build_id(const char *filename, void *bf, size_t size) 88 { 89 FILE *fp; 90 int ret = -1; 91 bool need_swap = false; 92 u8 e_ident[EI_NIDENT]; 93 size_t buf_size; 94 void *buf; 95 int i; 96 97 fp = fopen(filename, "r"); 98 if (fp == NULL) 99 return -1; 100 101 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1) 102 goto out; 103 104 if (memcmp(e_ident, ELFMAG, SELFMAG) || 105 e_ident[EI_VERSION] != EV_CURRENT) 106 goto out; 107 108 need_swap = check_need_swap(e_ident[EI_DATA]); 109 110 /* for simplicity */ 111 fseek(fp, 0, SEEK_SET); 112 113 if (e_ident[EI_CLASS] == ELFCLASS32) { 114 Elf32_Ehdr ehdr; 115 Elf32_Phdr *phdr; 116 117 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) 118 goto out; 119 120 if (need_swap) { 121 ehdr.e_phoff = bswap_32(ehdr.e_phoff); 122 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); 123 ehdr.e_phnum = bswap_16(ehdr.e_phnum); 124 } 125 126 buf_size = ehdr.e_phentsize * ehdr.e_phnum; 127 buf = malloc(buf_size); 128 if (buf == NULL) 129 goto out; 130 131 fseek(fp, ehdr.e_phoff, SEEK_SET); 132 if (fread(buf, buf_size, 1, fp) != 1) 133 goto out_free; 134 135 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { 136 void *tmp; 137 long offset; 138 139 if (need_swap) { 140 phdr->p_type = bswap_32(phdr->p_type); 141 phdr->p_offset = bswap_32(phdr->p_offset); 142 phdr->p_filesz = bswap_32(phdr->p_filesz); 143 } 144 145 if (phdr->p_type != PT_NOTE) 146 continue; 147 148 buf_size = phdr->p_filesz; 149 offset = phdr->p_offset; 150 tmp = realloc(buf, buf_size); 151 if (tmp == NULL) 152 goto out_free; 153 154 buf = tmp; 155 fseek(fp, offset, SEEK_SET); 156 if (fread(buf, buf_size, 1, fp) != 1) 157 goto out_free; 158 159 ret = read_build_id(buf, buf_size, bf, size, need_swap); 160 if (ret == 0) 161 ret = size; 162 break; 163 } 164 } else { 165 Elf64_Ehdr ehdr; 166 Elf64_Phdr *phdr; 167 168 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) 169 goto out; 170 171 if (need_swap) { 172 ehdr.e_phoff = bswap_64(ehdr.e_phoff); 173 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); 174 ehdr.e_phnum = bswap_16(ehdr.e_phnum); 175 } 176 177 buf_size = ehdr.e_phentsize * ehdr.e_phnum; 178 buf = malloc(buf_size); 179 if (buf == NULL) 180 goto out; 181 182 fseek(fp, ehdr.e_phoff, SEEK_SET); 183 if (fread(buf, buf_size, 1, fp) != 1) 184 goto out_free; 185 186 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { 187 void *tmp; 188 long offset; 189 190 if (need_swap) { 191 phdr->p_type = bswap_32(phdr->p_type); 192 phdr->p_offset = bswap_64(phdr->p_offset); 193 phdr->p_filesz = bswap_64(phdr->p_filesz); 194 } 195 196 if (phdr->p_type != PT_NOTE) 197 continue; 198 199 buf_size = phdr->p_filesz; 200 offset = phdr->p_offset; 201 tmp = realloc(buf, buf_size); 202 if (tmp == NULL) 203 goto out_free; 204 205 buf = tmp; 206 fseek(fp, offset, SEEK_SET); 207 if (fread(buf, buf_size, 1, fp) != 1) 208 goto out_free; 209 210 ret = read_build_id(buf, buf_size, bf, size, need_swap); 211 if (ret == 0) 212 ret = size; 213 break; 214 } 215 } 216 out_free: 217 free(buf); 218 out: 219 fclose(fp); 220 return ret; 221 } 222 223 int sysfs__read_build_id(const char *filename, void *build_id, size_t size) 224 { 225 int fd; 226 int ret = -1; 227 struct stat stbuf; 228 size_t buf_size; 229 void *buf; 230 231 fd = open(filename, O_RDONLY); 232 if (fd < 0) 233 return -1; 234 235 if (fstat(fd, &stbuf) < 0) 236 goto out; 237 238 buf_size = stbuf.st_size; 239 buf = malloc(buf_size); 240 if (buf == NULL) 241 goto out; 242 243 if (read(fd, buf, buf_size) != (ssize_t) buf_size) 244 goto out_free; 245 246 ret = read_build_id(buf, buf_size, build_id, size, false); 247 out_free: 248 free(buf); 249 out: 250 close(fd); 251 return ret; 252 } 253 254 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, 255 enum dso_binary_type type) 256 { 257 int fd = open(name, O_RDONLY); 258 if (fd < 0) 259 goto out_errno; 260 261 ss->name = strdup(name); 262 if (!ss->name) 263 goto out_close; 264 265 ss->fd = fd; 266 ss->type = type; 267 268 return 0; 269 out_close: 270 close(fd); 271 out_errno: 272 dso->load_errno = errno; 273 return -1; 274 } 275 276 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused) 277 { 278 /* Assume all sym sources could be a runtime image. */ 279 return true; 280 } 281 282 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused) 283 { 284 return false; 285 } 286 287 void symsrc__destroy(struct symsrc *ss) 288 { 289 zfree(&ss->name); 290 close(ss->fd); 291 } 292 293 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused, 294 struct symsrc *ss __maybe_unused) 295 { 296 return 0; 297 } 298 299 static int fd__is_64_bit(int fd) 300 { 301 u8 e_ident[EI_NIDENT]; 302 303 if (lseek(fd, 0, SEEK_SET)) 304 return -1; 305 306 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident)) 307 return -1; 308 309 if (memcmp(e_ident, ELFMAG, SELFMAG) || 310 e_ident[EI_VERSION] != EV_CURRENT) 311 return -1; 312 313 return e_ident[EI_CLASS] == ELFCLASS64; 314 } 315 316 enum dso_type dso__type_fd(int fd) 317 { 318 Elf64_Ehdr ehdr; 319 int ret; 320 321 ret = fd__is_64_bit(fd); 322 if (ret < 0) 323 return DSO__TYPE_UNKNOWN; 324 325 if (ret) 326 return DSO__TYPE_64BIT; 327 328 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr)) 329 return DSO__TYPE_UNKNOWN; 330 331 if (ehdr.e_machine == EM_X86_64) 332 return DSO__TYPE_X32BIT; 333 334 return DSO__TYPE_32BIT; 335 } 336 337 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused, 338 struct symsrc *ss, 339 struct symsrc *runtime_ss __maybe_unused, 340 int kmodule __maybe_unused) 341 { 342 unsigned char build_id[BUILD_ID_SIZE]; 343 int ret; 344 345 ret = fd__is_64_bit(ss->fd); 346 if (ret >= 0) 347 dso->is_64_bit = ret; 348 349 if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) { 350 dso__set_build_id(dso, build_id); 351 } 352 return 0; 353 } 354 355 int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused, 356 mapfn_t mapfn __maybe_unused, void *data __maybe_unused, 357 bool *is_64_bit __maybe_unused) 358 { 359 return -1; 360 } 361 362 int kcore_extract__create(struct kcore_extract *kce __maybe_unused) 363 { 364 return -1; 365 } 366 367 void kcore_extract__delete(struct kcore_extract *kce __maybe_unused) 368 { 369 } 370 371 int kcore_copy(const char *from_dir __maybe_unused, 372 const char *to_dir __maybe_unused) 373 { 374 return -1; 375 } 376 377 void symbol__elf_init(void) 378 { 379 } 380 381 char *dso__demangle_sym(struct dso *dso __maybe_unused, 382 int kmodule __maybe_unused, 383 const char *elf_name __maybe_unused) 384 { 385 return NULL; 386 } 387