tools/perf/util/srcline.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4
   5 #include <linux/kernel.h>
   6
   7 #include "util/dso.h"
   8 #include "util/util.h"
   9 #include "util/debug.h"
  10
  11 #include "symbol.h"
  12
  13 bool srcline_full_filename;
  14
  15 #ifdef HAVE_LIBBFD_SUPPORT
  16
  17 /*
  18  * Implement addr2line using libbfd.
  19  */
  20 #define PACKAGE "perf"
  21 #include <bfd.h>
  22
  23 struct a2l_data {
  24         const char      *input;
  25         u64             addr;
  26
  27         bool            found;
  28         const char      *filename;
  29         const char      *funcname;
  30         unsigned        line;
  31
  32         bfd             *abfd;
  33         asymbol         **syms;
  34 };
  35
  36 static int bfd_error(const char *string)
  37 {
  38         const char *errmsg;
  39
  40         errmsg = bfd_errmsg(bfd_get_error());
  41         fflush(stdout);
  42
  43         if (string)
  44                 pr_debug("%s: %s\n", string, errmsg);
  45         else
  46                 pr_debug("%s\n", errmsg);
  47
  48         return -1;
  49 }
  50
  51 static int slurp_symtab(bfd *abfd, struct a2l_data *a2l)
  52 {
  53         long storage;
  54         long symcount;
  55         asymbol **syms;
  56         bfd_boolean dynamic = FALSE;
  57
  58         if ((bfd_get_file_flags(abfd) & HAS_SYMS) == 0)
  59                 return bfd_error(bfd_get_filename(abfd));
  60
  61         storage = bfd_get_symtab_upper_bound(abfd);
  62         if (storage == 0L) {
  63                 storage = bfd_get_dynamic_symtab_upper_bound(abfd);
  64                 dynamic = TRUE;
  65         }
  66         if (storage < 0L)
  67                 return bfd_error(bfd_get_filename(abfd));
  68
  69         syms = malloc(storage);
  70         if (dynamic)
  71                 symcount = bfd_canonicalize_dynamic_symtab(abfd, syms);
  72         else
  73                 symcount = bfd_canonicalize_symtab(abfd, syms);
  74
  75         if (symcount < 0) {
  76                 free(syms);
  77                 return bfd_error(bfd_get_filename(abfd));
  78         }
  79
  80         a2l->syms = syms;
  81         return 0;
  82 }
  83
  84 static void find_address_in_section(bfd *abfd, asection *section, void *data)
  85 {
  86         bfd_vma pc, vma;
  87         bfd_size_type size;
  88         struct a2l_data *a2l = data;
  89         flagword flags;
  90
  91         if (a2l->found)
  92                 return;
  93
  94 #ifdef bfd_get_section_flags
  95         flags = bfd_get_section_flags(abfd, section);
  96 #else
  97         flags = bfd_section_flags(section);
  98 #endif
  99         if ((flags & SEC_ALLOC) == 0)
 100                 return;
 101
 102         pc = a2l->addr;
 103 #ifdef bfd_get_section_vma
 104         vma = bfd_get_section_vma(abfd, section);
 105 #else
 106         vma = bfd_section_vma(section);
 107 #endif
 108 #ifdef bfd_get_section_size
 109         size = bfd_get_section_size(section);
 110 #else
 111         size = bfd_section_size(section);
 112 #endif
 113
 114         if (pc < vma || pc >= vma + size)
 115                 return;
 116
 117         a2l->found = bfd_find_nearest_line(abfd, section, a2l->syms, pc - vma,
 118                                            &a2l->filename, &a2l->funcname,
 119                                            &a2l->line);
 120 }
 121
 122 static struct a2l_data *addr2line_init(const char *path)
 123 {
 124         bfd *abfd;
 125         struct a2l_data *a2l = NULL;
 126
 127         abfd = bfd_openr(path, NULL);
 128         if (abfd == NULL)
 129                 return NULL;
 130
 131         if (!bfd_check_format(abfd, bfd_object))
 132                 goto out;
 133
 134         a2l = zalloc(sizeof(*a2l));
 135         if (a2l == NULL)
 136                 goto out;
 137
 138         a2l->abfd = abfd;
 139         a2l->input = strdup(path);
 140         if (a2l->input == NULL)
 141                 goto out;
 142
 143         if (slurp_symtab(abfd, a2l))
 144                 goto out;
 145
 146         return a2l;
 147
 148 out:
 149         if (a2l) {
 150                 zfree((char **)&a2l->input);
 151                 free(a2l);
 152         }
 153         bfd_close(abfd);
 154         return NULL;
 155 }
 156
 157 static void addr2line_cleanup(struct a2l_data *a2l)
 158 {
 159         if (a2l->abfd)
 160                 bfd_close(a2l->abfd);
 161         zfree((char **)&a2l->input);
 162         zfree(&a2l->syms);
 163         free(a2l);
 164 }
 165
 166 #define MAX_INLINE_NEST 1024
 167
 168 static int addr2line(const char *dso_name, u64 addr,
 169                      char **file, unsigned int *line, struct dso *dso,
 170                      bool unwind_inlines)
 171 {
 172         int ret = 0;
 173         struct a2l_data *a2l = dso->a2l;
 174
 175         if (!a2l) {
 176                 dso->a2l = addr2line_init(dso_name);
 177                 a2l = dso->a2l;
 178         }
 179
 180         if (a2l == NULL) {
 181                 pr_warning("addr2line_init failed for %s\n", dso_name);
 182                 return 0;
 183         }
 184
 185         a2l->addr = addr;
 186         a2l->found = false;
 187
 188         bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);
 189
 190         if (a2l->found && unwind_inlines) {
 191                 int cnt = 0;
 192
 193                 while (bfd_find_inliner_info(a2l->abfd, &a2l->filename,
 194                                              &a2l->funcname, &a2l->line) &&
 195                        cnt++ < MAX_INLINE_NEST)
 196                         ;
 197         }
 198
 199         if (a2l->found && a2l->filename) {
 200                 *file = strdup(a2l->filename);
 201                 *line = a2l->line;
 202
 203                 if (*file)
 204                         ret = 1;
 205         }
 206
 207         return ret;
 208 }
 209
 210 void dso__free_a2l(struct dso *dso)
 211 {
 212         struct a2l_data *a2l = dso->a2l;
 213
 214         if (!a2l)
 215                 return;
 216
 217         addr2line_cleanup(a2l);
 218
 219         dso->a2l = NULL;
 220 }
 221
 222 #else /* HAVE_LIBBFD_SUPPORT */
 223
 224 static int addr2line(const char *dso_name, u64 addr,
 225                      char **file, unsigned int *line_nr,
 226                      struct dso *dso __maybe_unused,
 227                      bool unwind_inlines __maybe_unused)
 228 {
 229         FILE *fp;
 230         char cmd[PATH_MAX];
 231         char *filename = NULL;
 232         size_t len;
 233         char *sep;
 234         int ret = 0;
 235
 236         scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64,
 237                   dso_name, addr);
 238
 239         fp = popen(cmd, "r");
 240         if (fp == NULL) {
 241                 pr_warning("popen failed for %s\n", dso_name);
 242                 return 0;
 243         }
 244
 245         if (getline(&filename, &len, fp) < 0 || !len) {
 246                 pr_warning("addr2line has no output for %s\n", dso_name);
 247                 goto out;
 248         }
 249
 250         sep = strchr(filename, '\n');
 251         if (sep)
 252                 *sep = '\0';
 253
 254         if (!strcmp(filename, "??:0")) {
 255                 pr_debug("no debugging info in %s\n", dso_name);
 256                 free(filename);
 257                 goto out;
 258         }
 259
 260         sep = strchr(filename, ':');
 261         if (sep) {
 262                 *sep++ = '\0';
 263                 *file = filename;
 264                 *line_nr = strtoul(sep, NULL, 0);
 265                 ret = 1;
 266         }
 267 out:
 268         pclose(fp);
 269         return ret;
 270 }
 271
 272 void dso__free_a2l(struct dso *dso __maybe_unused)
 273 {
 274 }
 275
 276 #endif /* HAVE_LIBBFD_SUPPORT */
 277
 278 /*
 279  * Number of addr2line failures (without success) before disabling it for that
 280  * dso.
 281  */
 282 #define A2L_FAIL_LIMIT 123
 283
 284 char *__get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 285                   bool show_sym, bool unwind_inlines)
 286 {
 287         char *file = NULL;
 288         unsigned line = 0;
 289         char *srcline;
 290         const char *dso_name;
 291
 292         if (!dso->has_srcline)
 293                 goto out;
 294
 295         if (dso->symsrc_filename)
 296                 dso_name = dso->symsrc_filename;
 297         else
 298                 dso_name = dso->long_name;
 299
 300         if (dso_name[0] == '[')
 301                 goto out;
 302
 303         if (!strncmp(dso_name, "/tmp/perf-", 10))
 304                 goto out;
 305
 306         if (!addr2line(dso_name, addr, &file, &line, dso, unwind_inlines))
 307                 goto out;
 308
 309         if (asprintf(&srcline, "%s:%u",
 310                                 srcline_full_filename ? file : basename(file),
 311                                 line) < 0) {
 312                 free(file);
 313                 goto out;
 314         }
 315
 316         dso->a2l_fails = 0;
 317
 318         free(file);
 319         return srcline;
 320
 321 out:
 322         if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
 323                 dso->has_srcline = 0;
 324                 dso__free_a2l(dso);
 325         }
 326         if (sym) {
 327                 if (asprintf(&srcline, "%s+%" PRIu64, show_sym ? sym->name : "",
 328                                         addr - sym->start) < 0)
 329                         return SRCLINE_UNKNOWN;
 330         } else if (asprintf(&srcline, "%s[%" PRIx64 "]", dso->short_name, addr) < 0)
 331                 return SRCLINE_UNKNOWN;
 332         return srcline;
 333 }
 334
 335 void free_srcline(char *srcline)
 336 {
 337         if (srcline && strcmp(srcline, SRCLINE_UNKNOWN) != 0)
 338                 free(srcline);
 339 }
 340
 341 char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 342                   bool show_sym)
 343 {
 344         return __get_srcline(dso, addr, sym, show_sym, false);
 345 }