1 // SPDX-License-Identifier: GPL-2.0 2 #include "dso.h" 3 #include "symbol.h" 4 #include "symsrc.h" 5 #include "util.h" 6 7 #include <errno.h> 8 #include <unistd.h> 9 #include <stdio.h> 10 #include <fcntl.h> 11 #include <string.h> 12 #include <stdlib.h> 13 #include <byteswap.h> 14 #include <sys/stat.h> 15 #include <linux/zalloc.h> 16 17 static bool check_need_swap(int file_endian) 18 { 19 const int data = 1; 20 u8 *check = (u8 *)&data; 21 int host_endian; 22 23 if (check[0] == 1) 24 host_endian = ELFDATA2LSB; 25 else 26 host_endian = ELFDATA2MSB; 27 28 return host_endian != file_endian; 29 } 30 31 #define NOTE_ALIGN(sz) (((sz) + 3) & ~3) 32 33 #define NT_GNU_BUILD_ID 3 34 35 static int read_build_id(void *note_data, size_t note_len, void *bf, 36 size_t size, bool need_swap) 37 { 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(bf, ptr, sz); 68 memset(bf + sz, 0, size - sz); 69 return 0; 70 } 71 } 72 ptr += descsz; 73 } 74 75 return -1; 76 } 77 78 int filename__read_debuglink(const char *filename __maybe_unused, 79 char *debuglink __maybe_unused, 80 size_t size __maybe_unused) 81 { 82 return -1; 83 } 84 85 /* 86 * Just try PT_NOTE header otherwise fails 87 */ 88 int filename__read_build_id(const char *filename, void *bf, size_t size) 89 { 90 FILE *fp; 91 int ret = -1; 92 bool need_swap = false; 93 u8 e_ident[EI_NIDENT]; 94 size_t buf_size; 95 void *buf; 96 int i; 97 98 fp = fopen(filename, "r"); 99 if (fp == NULL) 100 return -1; 101 102 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1) 103 goto out; 104 105 if (memcmp(e_ident, ELFMAG, SELFMAG) || 106 e_ident[EI_VERSION] != EV_CURRENT) 107 goto out; 108 109 need_swap = check_need_swap(e_ident[EI_DATA]); 110 111 /* for simplicity */ 112 fseek(fp, 0, SEEK_SET); 113 114 if (e_ident[EI_CLASS] == ELFCLASS32) { 115 Elf32_Ehdr ehdr; 116 Elf32_Phdr *phdr; 117 118 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) 119 goto out; 120 121 if (need_swap) { 122 ehdr.e_phoff = bswap_32(ehdr.e_phoff); 123 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); 124 ehdr.e_phnum = bswap_16(ehdr.e_phnum); 125 } 126 127 buf_size = ehdr.e_phentsize * ehdr.e_phnum; 128 buf = malloc(buf_size); 129 if (buf == NULL) 130 goto out; 131 132 fseek(fp, ehdr.e_phoff, SEEK_SET); 133 if (fread(buf, buf_size, 1, fp) != 1) 134 goto out_free; 135 136 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { 137 void *tmp; 138 long offset; 139 140 if (need_swap) { 141 phdr->p_type = bswap_32(phdr->p_type); 142 phdr->p_offset = bswap_32(phdr->p_offset); 143 phdr->p_filesz = bswap_32(phdr->p_filesz); 144 } 145 146 if (phdr->p_type != PT_NOTE) 147 continue; 148 149 buf_size = phdr->p_filesz; 150 offset = phdr->p_offset; 151 tmp = realloc(buf, buf_size); 152 if (tmp == NULL) 153 goto out_free; 154 155 buf = tmp; 156 fseek(fp, offset, SEEK_SET); 157 if (fread(buf, buf_size, 1, fp) != 1) 158 goto out_free; 159 160 ret = read_build_id(buf, buf_size, bf, size, need_swap); 161 if (ret == 0) 162 ret = size; 163 break; 164 } 165 } else { 166 Elf64_Ehdr ehdr; 167 Elf64_Phdr *phdr; 168 169 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) 170 goto out; 171 172 if (need_swap) { 173 ehdr.e_phoff = bswap_64(ehdr.e_phoff); 174 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); 175 ehdr.e_phnum = bswap_16(ehdr.e_phnum); 176 } 177 178 buf_size = ehdr.e_phentsize * ehdr.e_phnum; 179 buf = malloc(buf_size); 180 if (buf == NULL) 181 goto out; 182 183 fseek(fp, ehdr.e_phoff, SEEK_SET); 184 if (fread(buf, buf_size, 1, fp) != 1) 185 goto out_free; 186 187 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { 188 void *tmp; 189 long offset; 190 191 if (need_swap) { 192 phdr->p_type = bswap_32(phdr->p_type); 193 phdr->p_offset = bswap_64(phdr->p_offset); 194 phdr->p_filesz = bswap_64(phdr->p_filesz); 195 } 196 197 if (phdr->p_type != PT_NOTE) 198 continue; 199 200 buf_size = phdr->p_filesz; 201 offset = phdr->p_offset; 202 tmp = realloc(buf, buf_size); 203 if (tmp == NULL) 204 goto out_free; 205 206 buf = tmp; 207 fseek(fp, offset, SEEK_SET); 208 if (fread(buf, buf_size, 1, fp) != 1) 209 goto out_free; 210 211 ret = read_build_id(buf, buf_size, bf, size, need_swap); 212 if (ret == 0) 213 ret = size; 214 break; 215 } 216 } 217 out_free: 218 free(buf); 219 out: 220 fclose(fp); 221 return ret; 222 } 223 224 int sysfs__read_build_id(const char *filename, void *build_id, size_t size) 225 { 226 int fd; 227 int ret = -1; 228 struct stat stbuf; 229 size_t buf_size; 230 void *buf; 231 232 fd = open(filename, O_RDONLY); 233 if (fd < 0) 234 return -1; 235 236 if (fstat(fd, &stbuf) < 0) 237 goto out; 238 239 buf_size = stbuf.st_size; 240 buf = malloc(buf_size); 241 if (buf == NULL) 242 goto out; 243 244 if (read(fd, buf, buf_size) != (ssize_t) buf_size) 245 goto out_free; 246 247 ret = read_build_id(buf, buf_size, build_id, size, false); 248 out_free: 249 free(buf); 250 out: 251 close(fd); 252 return ret; 253 } 254 255 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, 256 enum dso_binary_type type) 257 { 258 int fd = open(name, O_RDONLY); 259 if (fd < 0) 260 goto out_errno; 261 262 ss->name = strdup(name); 263 if (!ss->name) 264 goto out_close; 265 266 ss->fd = fd; 267 ss->type = type; 268 269 return 0; 270 out_close: 271 close(fd); 272 out_errno: 273 dso->load_errno = errno; 274 return -1; 275 } 276 277 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused) 278 { 279 /* Assume all sym sources could be a runtime image. */ 280 return true; 281 } 282 283 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused) 284 { 285 return false; 286 } 287 288 void symsrc__destroy(struct symsrc *ss) 289 { 290 zfree(&ss->name); 291 close(ss->fd); 292 } 293 294 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused, 295 struct symsrc *ss __maybe_unused) 296 { 297 return 0; 298 } 299 300 static int fd__is_64_bit(int fd) 301 { 302 u8 e_ident[EI_NIDENT]; 303 304 if (lseek(fd, 0, SEEK_SET)) 305 return -1; 306 307 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident)) 308 return -1; 309 310 if (memcmp(e_ident, ELFMAG, SELFMAG) || 311 e_ident[EI_VERSION] != EV_CURRENT) 312 return -1; 313 314 return e_ident[EI_CLASS] == ELFCLASS64; 315 } 316 317 enum dso_type dso__type_fd(int fd) 318 { 319 Elf64_Ehdr ehdr; 320 int ret; 321 322 ret = fd__is_64_bit(fd); 323 if (ret < 0) 324 return DSO__TYPE_UNKNOWN; 325 326 if (ret) 327 return DSO__TYPE_64BIT; 328 329 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr)) 330 return DSO__TYPE_UNKNOWN; 331 332 if (ehdr.e_machine == EM_X86_64) 333 return DSO__TYPE_X32BIT; 334 335 return DSO__TYPE_32BIT; 336 } 337 338 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused, 339 struct symsrc *ss, 340 struct symsrc *runtime_ss __maybe_unused, 341 int kmodule __maybe_unused) 342 { 343 unsigned char build_id[BUILD_ID_SIZE]; 344 int ret; 345 346 ret = fd__is_64_bit(ss->fd); 347 if (ret >= 0) 348 dso->is_64_bit = ret; 349 350 if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) { 351 dso__set_build_id(dso, build_id); 352 } 353 return 0; 354 } 355 356 int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused, 357 mapfn_t mapfn __maybe_unused, void *data __maybe_unused, 358 bool *is_64_bit __maybe_unused) 359 { 360 return -1; 361 } 362 363 int kcore_extract__create(struct kcore_extract *kce __maybe_unused) 364 { 365 return -1; 366 } 367 368 void kcore_extract__delete(struct kcore_extract *kce __maybe_unused) 369 { 370 } 371 372 int kcore_copy(const char *from_dir __maybe_unused, 373 const char *to_dir __maybe_unused) 374 { 375 return -1; 376 } 377 378 void symbol__elf_init(void) 379 { 380 } 381 382 char *dso__demangle_sym(struct dso *dso __maybe_unused, 383 int kmodule __maybe_unused, 384 const char *elf_name __maybe_unused) 385 { 386 return NULL; 387 } 388