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