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
  90         if (a2l->found)
  91                 return;
  92
  93         if ((bfd_get_section_flags(abfd, section) & SEC_ALLOC) == 0)
  94                 return;
  95
  96         pc = a2l->addr;
  97         vma = bfd_get_section_vma(abfd, section);
  98         size = bfd_get_section_size(section);
  99
 100         if (pc < vma || pc >= vma + size)
 101                 return;
 102
 103         a2l->found = bfd_find_nearest_line(abfd, section, a2l->syms, pc - vma,
 104                                            &a2l->filename, &a2l->funcname,
 105                                            &a2l->line);
 106 }
 107
 108 static struct a2l_data *addr2line_init(const char *path)
 109 {
 110         bfd *abfd;
 111         struct a2l_data *a2l = NULL;
 112
 113         abfd = bfd_openr(path, NULL);
 114         if (abfd == NULL)
 115                 return NULL;
 116
 117         if (!bfd_check_format(abfd, bfd_object))
 118                 goto out;
 119
 120         a2l = zalloc(sizeof(*a2l));
 121         if (a2l == NULL)
 122                 goto out;
 123
 124         a2l->abfd = abfd;
 125         a2l->input = strdup(path);
 126         if (a2l->input == NULL)
 127                 goto out;
 128
 129         if (slurp_symtab(abfd, a2l))
 130                 goto out;
 131
 132         return a2l;
 133
 134 out:
 135         if (a2l) {
 136                 zfree((char **)&a2l->input);
 137                 free(a2l);
 138         }
 139         bfd_close(abfd);
 140         return NULL;
 141 }
 142
 143 static void addr2line_cleanup(struct a2l_data *a2l)
 144 {
 145         if (a2l->abfd)
 146                 bfd_close(a2l->abfd);
 147         zfree((char **)&a2l->input);
 148         zfree(&a2l->syms);
 149         free(a2l);
 150 }
 151
 152 static int addr2line(const char *dso_name, u64 addr,
 153                      char **file, unsigned int *line, struct dso *dso)
 154 {
 155         int ret = 0;
 156         struct a2l_data *a2l = dso->a2l;
 157
 158         if (!a2l) {
 159                 dso->a2l = addr2line_init(dso_name);
 160                 a2l = dso->a2l;
 161         }
 162
 163         if (a2l == NULL) {
 164                 pr_warning("addr2line_init failed for %s\n", dso_name);
 165                 return 0;
 166         }
 167
 168         a2l->addr = addr;
 169         a2l->found = false;
 170
 171         bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);
 172
 173         if (a2l->found && a2l->filename) {
 174                 *file = strdup(a2l->filename);
 175                 *line = a2l->line;
 176
 177                 if (*file)
 178                         ret = 1;
 179         }
 180
 181         return ret;
 182 }
 183
 184 void dso__free_a2l(struct dso *dso)
 185 {
 186         struct a2l_data *a2l = dso->a2l;
 187
 188         if (!a2l)
 189                 return;
 190
 191         addr2line_cleanup(a2l);
 192
 193         dso->a2l = NULL;
 194 }
 195
 196 #else /* HAVE_LIBBFD_SUPPORT */
 197
 198 static int addr2line(const char *dso_name, u64 addr,
 199                      char **file, unsigned int *line_nr,
 200                      struct dso *dso __maybe_unused)
 201 {
 202         FILE *fp;
 203         char cmd[PATH_MAX];
 204         char *filename = NULL;
 205         size_t len;
 206         char *sep;
 207         int ret = 0;
 208
 209         scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64,
 210                   dso_name, addr);
 211
 212         fp = popen(cmd, "r");
 213         if (fp == NULL) {
 214                 pr_warning("popen failed for %s\n", dso_name);
 215                 return 0;
 216         }
 217
 218         if (getline(&filename, &len, fp) < 0 || !len) {
 219                 pr_warning("addr2line has no output for %s\n", dso_name);
 220                 goto out;
 221         }
 222
 223         sep = strchr(filename, '\n');
 224         if (sep)
 225                 *sep = '\0';
 226
 227         if (!strcmp(filename, "??:0")) {
 228                 pr_debug("no debugging info in %s\n", dso_name);
 229                 free(filename);
 230                 goto out;
 231         }
 232
 233         sep = strchr(filename, ':');
 234         if (sep) {
 235                 *sep++ = '\0';
 236                 *file = filename;
 237                 *line_nr = strtoul(sep, NULL, 0);
 238                 ret = 1;
 239         }
 240 out:
 241         pclose(fp);
 242         return ret;
 243 }
 244
 245 void dso__free_a2l(struct dso *dso __maybe_unused)
 246 {
 247 }
 248
 249 #endif /* HAVE_LIBBFD_SUPPORT */
 250
 251 /*
 252  * Number of addr2line failures (without success) before disabling it for that
 253  * dso.
 254  */
 255 #define A2L_FAIL_LIMIT 123
 256
 257 char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 258                   bool show_sym)
 259 {
 260         char *file = NULL;
 261         unsigned line = 0;
 262         char *srcline;
 263         const char *dso_name;
 264
 265         if (!dso->has_srcline)
 266                 goto out;
 267
 268         if (dso->symsrc_filename)
 269                 dso_name = dso->symsrc_filename;
 270         else
 271                 dso_name = dso->long_name;
 272
 273         if (dso_name[0] == '[')
 274                 goto out;
 275
 276         if (!strncmp(dso_name, "/tmp/perf-", 10))
 277                 goto out;
 278
 279         if (!addr2line(dso_name, addr, &file, &line, dso))
 280                 goto out;
 281
 282         if (asprintf(&srcline, "%s:%u",
 283                                 srcline_full_filename ? file : basename(file),
 284                                 line) < 0) {
 285                 free(file);
 286                 goto out;
 287         }
 288
 289         dso->a2l_fails = 0;
 290
 291         free(file);
 292         return srcline;
 293
 294 out:
 295         if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
 296                 dso->has_srcline = 0;
 297                 dso__free_a2l(dso);
 298         }
 299         if (sym) {
 300                 if (asprintf(&srcline, "%s+%" PRIu64, show_sym ? sym->name : "",
 301                                         addr - sym->start) < 0)
 302                         return SRCLINE_UNKNOWN;
 303         } else if (asprintf(&srcline, "%s[%" PRIx64 "]", dso->short_name, addr) < 0)
 304                 return SRCLINE_UNKNOWN;
 305         return srcline;
 306 }
 307
 308 void free_srcline(char *srcline)
 309 {
 310         if (srcline && strcmp(srcline, SRCLINE_UNKNOWN) != 0)
 311                 free(srcline);
 312 }