tools/perf/util/symbol-minimal.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "symbol.h"
   3 #include "util.h"
   4
   5 #include <errno.h>
   6 #include <stdio.h>
   7 #include <fcntl.h>
   8 #include <string.h>
   9 #include <byteswap.h>
  10 #include <sys/stat.h>
  11
  12
  13 static bool check_need_swap(int file_endian)
  14 {
  15         const int data = 1;
  16         u8 *check = (u8 *)&data;
  17         int host_endian;
  18
  19         if (check[0] == 1)
  20                 host_endian = ELFDATA2LSB;
  21         else
  22                 host_endian = ELFDATA2MSB;
  23
  24         return host_endian != file_endian;
  25 }
  26
  27 #define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
  28
  29 #define NT_GNU_BUILD_ID 3
  30
  31 static int read_build_id(void *note_data, size_t note_len, void *bf,
  32                          size_t size, bool need_swap)
  33 {
  34         struct {
  35                 u32 n_namesz;
  36                 u32 n_descsz;
  37                 u32 n_type;
  38         } *nhdr;
  39         void *ptr;
  40
  41         ptr = note_data;
  42         while (ptr < (note_data + note_len)) {
  43                 const char *name;
  44                 size_t namesz, descsz;
  45
  46                 nhdr = ptr;
  47                 if (need_swap) {
  48                         nhdr->n_namesz = bswap_32(nhdr->n_namesz);
  49                         nhdr->n_descsz = bswap_32(nhdr->n_descsz);
  50                         nhdr->n_type = bswap_32(nhdr->n_type);
  51                 }
  52
  53                 namesz = NOTE_ALIGN(nhdr->n_namesz);
  54                 descsz = NOTE_ALIGN(nhdr->n_descsz);
  55
  56                 ptr += sizeof(*nhdr);
  57                 name = ptr;
  58                 ptr += namesz;
  59                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
  60                     nhdr->n_namesz == sizeof("GNU")) {
  61                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
  62                                 size_t sz = min(size, descsz);
  63                                 memcpy(bf, ptr, sz);
  64                                 memset(bf + sz, 0, size - sz);
  65                                 return 0;
  66                         }
  67                 }
  68                 ptr += descsz;
  69         }
  70
  71         return -1;
  72 }
  73
  74 int filename__read_debuglink(const char *filename __maybe_unused,
  75                              char *debuglink __maybe_unused,
  76                              size_t size __maybe_unused)
  77 {
  78         return -1;
  79 }
  80
  81 /*
  82  * Just try PT_NOTE header otherwise fails
  83  */
  84 int filename__read_build_id(const char *filename, void *bf, size_t size)
  85 {
  86         FILE *fp;
  87         int ret = -1;
  88         bool need_swap = false;
  89         u8 e_ident[EI_NIDENT];
  90         size_t buf_size;
  91         void *buf;
  92         int i;
  93
  94         fp = fopen(filename, "r");
  95         if (fp == NULL)
  96                 return -1;
  97
  98         if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
  99                 goto out;
 100
 101         if (memcmp(e_ident, ELFMAG, SELFMAG) ||
 102             e_ident[EI_VERSION] != EV_CURRENT)
 103                 goto out;
 104
 105         need_swap = check_need_swap(e_ident[EI_DATA]);
 106
 107         /* for simplicity */
 108         fseek(fp, 0, SEEK_SET);
 109
 110         if (e_ident[EI_CLASS] == ELFCLASS32) {
 111                 Elf32_Ehdr ehdr;
 112                 Elf32_Phdr *phdr;
 113
 114                 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
 115                         goto out;
 116
 117                 if (need_swap) {
 118                         ehdr.e_phoff = bswap_32(ehdr.e_phoff);
 119                         ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
 120                         ehdr.e_phnum = bswap_16(ehdr.e_phnum);
 121                 }
 122
 123                 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
 124                 buf = malloc(buf_size);
 125                 if (buf == NULL)
 126                         goto out;
 127
 128                 fseek(fp, ehdr.e_phoff, SEEK_SET);
 129                 if (fread(buf, buf_size, 1, fp) != 1)
 130                         goto out_free;
 131
 132                 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
 133                         void *tmp;
 134                         long offset;
 135
 136                         if (need_swap) {
 137                                 phdr->p_type = bswap_32(phdr->p_type);
 138                                 phdr->p_offset = bswap_32(phdr->p_offset);
 139                                 phdr->p_filesz = bswap_32(phdr->p_filesz);
 140                         }
 141
 142                         if (phdr->p_type != PT_NOTE)
 143                                 continue;
 144
 145                         buf_size = phdr->p_filesz;
 146                         offset = phdr->p_offset;
 147                         tmp = realloc(buf, buf_size);
 148                         if (tmp == NULL)
 149                                 goto out_free;
 150
 151                         buf = tmp;
 152                         fseek(fp, offset, SEEK_SET);
 153                         if (fread(buf, buf_size, 1, fp) != 1)
 154                                 goto out_free;
 155
 156                         ret = read_build_id(buf, buf_size, bf, size, need_swap);
 157                         if (ret == 0)
 158                                 ret = size;
 159                         break;
 160                 }
 161         } else {
 162                 Elf64_Ehdr ehdr;
 163                 Elf64_Phdr *phdr;
 164
 165                 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
 166                         goto out;
 167
 168                 if (need_swap) {
 169                         ehdr.e_phoff = bswap_64(ehdr.e_phoff);
 170                         ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
 171                         ehdr.e_phnum = bswap_16(ehdr.e_phnum);
 172                 }
 173
 174                 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
 175                 buf = malloc(buf_size);
 176                 if (buf == NULL)
 177                         goto out;
 178
 179                 fseek(fp, ehdr.e_phoff, SEEK_SET);
 180                 if (fread(buf, buf_size, 1, fp) != 1)
 181                         goto out_free;
 182
 183                 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
 184                         void *tmp;
 185                         long offset;
 186
 187                         if (need_swap) {
 188                                 phdr->p_type = bswap_32(phdr->p_type);
 189                                 phdr->p_offset = bswap_64(phdr->p_offset);
 190                                 phdr->p_filesz = bswap_64(phdr->p_filesz);
 191                         }
 192
 193                         if (phdr->p_type != PT_NOTE)
 194                                 continue;
 195
 196                         buf_size = phdr->p_filesz;
 197                         offset = phdr->p_offset;
 198                         tmp = realloc(buf, buf_size);
 199                         if (tmp == NULL)
 200                                 goto out_free;
 201
 202                         buf = tmp;
 203                         fseek(fp, offset, SEEK_SET);
 204                         if (fread(buf, buf_size, 1, fp) != 1)
 205                                 goto out_free;
 206
 207                         ret = read_build_id(buf, buf_size, bf, size, need_swap);
 208                         if (ret == 0)
 209                                 ret = size;
 210                         break;
 211                 }
 212         }
 213 out_free:
 214         free(buf);
 215 out:
 216         fclose(fp);
 217         return ret;
 218 }
 219
 220 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 221 {
 222         int fd;
 223         int ret = -1;
 224         struct stat stbuf;
 225         size_t buf_size;
 226         void *buf;
 227
 228         fd = open(filename, O_RDONLY);
 229         if (fd < 0)
 230                 return -1;
 231
 232         if (fstat(fd, &stbuf) < 0)
 233                 goto out;
 234
 235         buf_size = stbuf.st_size;
 236         buf = malloc(buf_size);
 237         if (buf == NULL)
 238                 goto out;
 239
 240         if (read(fd, buf, buf_size) != (ssize_t) buf_size)
 241                 goto out_free;
 242
 243         ret = read_build_id(buf, buf_size, build_id, size, false);
 244 out_free:
 245         free(buf);
 246 out:
 247         close(fd);
 248         return ret;
 249 }
 250
 251 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
 252                  enum dso_binary_type type)
 253 {
 254         int fd = open(name, O_RDONLY);
 255         if (fd < 0)
 256                 goto out_errno;
 257
 258         ss->name = strdup(name);
 259         if (!ss->name)
 260                 goto out_close;
 261
 262         ss->fd = fd;
 263         ss->type = type;
 264
 265         return 0;
 266 out_close:
 267         close(fd);
 268 out_errno:
 269         dso->load_errno = errno;
 270         return -1;
 271 }
 272
 273 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
 274 {
 275         /* Assume all sym sources could be a runtime image. */
 276         return true;
 277 }
 278
 279 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
 280 {
 281         return false;
 282 }
 283
 284 void symsrc__destroy(struct symsrc *ss)
 285 {
 286         zfree(&ss->name);
 287         close(ss->fd);
 288 }
 289
 290 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
 291                                 struct symsrc *ss __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                         const char *elf_name __maybe_unused)
 381 {
 382         return NULL;
 383 }