tools/perf/util/symbol-minimal.c

   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 }