tools/perf/util/symbol-minimal.c

   1 #include "symbol.h"
   2
   3 #include <stdio.h>
   4 #include <fcntl.h>
   5 #include <string.h>
   6 #include <byteswap.h>
   7 #include <sys/stat.h>
   8
   9
  10 static bool check_need_swap(int file_endian)
  11 {
  12         const int data = 1;
  13         u8 *check = (u8 *)&data;
  14         int host_endian;
  15
  16         if (check[0] == 1)
  17                 host_endian = ELFDATA2LSB;
  18         else
  19                 host_endian = ELFDATA2MSB;
  20
  21         return host_endian != file_endian;
  22 }
  23
  24 #define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
  25
  26 #define NT_GNU_BUILD_ID 3
  27
  28 static int read_build_id(void *note_data, size_t note_len, void *bf,
  29                          size_t size, bool need_swap)
  30 {
  31         struct {
  32                 u32 n_namesz;
  33                 u32 n_descsz;
  34                 u32 n_type;
  35         } *nhdr;
  36         void *ptr;
  37
  38         ptr = note_data;
  39         while (ptr < (note_data + note_len)) {
  40                 const char *name;
  41                 size_t namesz, descsz;
  42
  43                 nhdr = ptr;
  44                 if (need_swap) {
  45                         nhdr->n_namesz = bswap_32(nhdr->n_namesz);
  46                         nhdr->n_descsz = bswap_32(nhdr->n_descsz);
  47                         nhdr->n_type = bswap_32(nhdr->n_type);
  48                 }
  49
  50                 namesz = NOTE_ALIGN(nhdr->n_namesz);
  51                 descsz = NOTE_ALIGN(nhdr->n_descsz);
  52
  53                 ptr += sizeof(*nhdr);
  54                 name = ptr;
  55                 ptr += namesz;
  56                 if (nhdr->n_type == NT_GNU_BUILD_ID &&
  57                     nhdr->n_namesz == sizeof("GNU")) {
  58                         if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
  59                                 size_t sz = min(size, descsz);
  60                                 memcpy(bf, ptr, sz);
  61                                 memset(bf + sz, 0, size - sz);
  62                                 return 0;
  63                         }
  64                 }
  65                 ptr += descsz;
  66         }
  67
  68         return -1;
  69 }
  70
  71 int filename__read_debuglink(const char *filename __maybe_unused,
  72                              char *debuglink __maybe_unused,
  73                              size_t size __maybe_unused)
  74 {
  75         return -1;
  76 }
  77
  78 /*
  79  * Just try PT_NOTE header otherwise fails
  80  */
  81 int filename__read_build_id(const char *filename, void *bf, size_t size)
  82 {
  83         FILE *fp;
  84         int ret = -1;
  85         bool need_swap = false;
  86         u8 e_ident[EI_NIDENT];
  87         size_t buf_size;
  88         void *buf;
  89         int i;
  90
  91         fp = fopen(filename, "r");
  92         if (fp == NULL)
  93                 return -1;
  94
  95         if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
  96                 goto out;
  97
  98         if (memcmp(e_ident, ELFMAG, SELFMAG) ||
  99             e_ident[EI_VERSION] != EV_CURRENT)
 100                 goto out;
 101
 102         need_swap = check_need_swap(e_ident[EI_DATA]);
 103
 104         /* for simplicity */
 105         fseek(fp, 0, SEEK_SET);
 106
 107         if (e_ident[EI_CLASS] == ELFCLASS32) {
 108                 Elf32_Ehdr ehdr;
 109                 Elf32_Phdr *phdr;
 110
 111                 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
 112                         goto out;
 113
 114                 if (need_swap) {
 115                         ehdr.e_phoff = bswap_32(ehdr.e_phoff);
 116                         ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
 117                         ehdr.e_phnum = bswap_16(ehdr.e_phnum);
 118                 }
 119
 120                 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
 121                 buf = malloc(buf_size);
 122                 if (buf == NULL)
 123                         goto out;
 124
 125                 fseek(fp, ehdr.e_phoff, SEEK_SET);
 126                 if (fread(buf, buf_size, 1, fp) != 1)
 127                         goto out_free;
 128
 129                 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
 130                         void *tmp;
 131
 132                         if (need_swap) {
 133                                 phdr->p_type = bswap_32(phdr->p_type);
 134                                 phdr->p_offset = bswap_32(phdr->p_offset);
 135                                 phdr->p_filesz = bswap_32(phdr->p_filesz);
 136                         }
 137
 138                         if (phdr->p_type != PT_NOTE)
 139                                 continue;
 140
 141                         buf_size = phdr->p_filesz;
 142                         tmp = realloc(buf, buf_size);
 143                         if (tmp == NULL)
 144                                 goto out_free;
 145
 146                         buf = tmp;
 147                         fseek(fp, phdr->p_offset, SEEK_SET);
 148                         if (fread(buf, buf_size, 1, fp) != 1)
 149                                 goto out_free;
 150
 151                         ret = read_build_id(buf, buf_size, bf, size, need_swap);
 152                         if (ret == 0)
 153                                 ret = size;
 154                         break;
 155                 }
 156         } else {
 157                 Elf64_Ehdr ehdr;
 158                 Elf64_Phdr *phdr;
 159
 160                 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
 161                         goto out;
 162
 163                 if (need_swap) {
 164                         ehdr.e_phoff = bswap_64(ehdr.e_phoff);
 165                         ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
 166                         ehdr.e_phnum = bswap_16(ehdr.e_phnum);
 167                 }
 168
 169                 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
 170                 buf = malloc(buf_size);
 171                 if (buf == NULL)
 172                         goto out;
 173
 174                 fseek(fp, ehdr.e_phoff, SEEK_SET);
 175                 if (fread(buf, buf_size, 1, fp) != 1)
 176                         goto out_free;
 177
 178                 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
 179                         void *tmp;
 180
 181                         if (need_swap) {
 182                                 phdr->p_type = bswap_32(phdr->p_type);
 183                                 phdr->p_offset = bswap_64(phdr->p_offset);
 184                                 phdr->p_filesz = bswap_64(phdr->p_filesz);
 185                         }
 186
 187                         if (phdr->p_type != PT_NOTE)
 188                                 continue;
 189
 190                         buf_size = phdr->p_filesz;
 191                         tmp = realloc(buf, buf_size);
 192                         if (tmp == NULL)
 193                                 goto out_free;
 194
 195                         buf = tmp;
 196                         fseek(fp, phdr->p_offset, SEEK_SET);
 197                         if (fread(buf, buf_size, 1, fp) != 1)
 198                                 goto out_free;
 199
 200                         ret = read_build_id(buf, buf_size, bf, size, need_swap);
 201                         if (ret == 0)
 202                                 ret = size;
 203                         break;
 204                 }
 205         }
 206 out_free:
 207         free(buf);
 208 out:
 209         fclose(fp);
 210         return ret;
 211 }
 212
 213 int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
 214 {
 215         int fd;
 216         int ret = -1;
 217         struct stat stbuf;
 218         size_t buf_size;
 219         void *buf;
 220
 221         fd = open(filename, O_RDONLY);
 222         if (fd < 0)
 223                 return -1;
 224
 225         if (fstat(fd, &stbuf) < 0)
 226                 goto out;
 227
 228         buf_size = stbuf.st_size;
 229         buf = malloc(buf_size);
 230         if (buf == NULL)
 231                 goto out;
 232
 233         if (read(fd, buf, buf_size) != (ssize_t) buf_size)
 234                 goto out_free;
 235
 236         ret = read_build_id(buf, buf_size, build_id, size, false);
 237 out_free:
 238         free(buf);
 239 out:
 240         close(fd);
 241         return ret;
 242 }
 243
 244 int symsrc__init(struct symsrc *ss, struct dso *dso __maybe_unused,
 245                  const char *name,
 246                  enum dso_binary_type type)
 247 {
 248         int fd = open(name, O_RDONLY);
 249         if (fd < 0)
 250                 return -1;
 251
 252         ss->name = strdup(name);
 253         if (!ss->name)
 254                 goto out_close;
 255
 256         ss->type = type;
 257
 258         return 0;
 259 out_close:
 260         close(fd);
 261         return -1;
 262 }
 263
 264 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
 265 {
 266         /* Assume all sym sources could be a runtime image. */
 267         return true;
 268 }
 269
 270 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
 271 {
 272         return false;
 273 }
 274
 275 void symsrc__destroy(struct symsrc *ss)
 276 {
 277         free(ss->name);
 278         close(ss->fd);
 279 }
 280
 281 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
 282                                 struct symsrc *ss __maybe_unused,
 283                                 struct map *map __maybe_unused,
 284                                 symbol_filter_t filter __maybe_unused)
 285 {
 286         return 0;
 287 }
 288
 289 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
 290                   struct symsrc *ss,
 291                   struct symsrc *runtime_ss __maybe_unused,
 292                   symbol_filter_t filter __maybe_unused,
 293                   int kmodule __maybe_unused)
 294 {
 295         unsigned char *build_id[BUILD_ID_SIZE];
 296
 297         if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) {
 298                 dso__set_build_id(dso, build_id);
 299                 return 1;
 300         }
 301         return 0;
 302 }
 303
 304 int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
 305                     mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
 306                     bool *is_64_bit __maybe_unused)
 307 {
 308         return -1;
 309 }
 310
 311 void symbol__elf_init(void)
 312 {
 313 }