tools/perf/util/symbol-minimal.c

   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 }