tools/perf/util/symbol-minimal.c

   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 }