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 #define MAX_INLINE_NEST 1024
 153
 154 static int addr2line(const char *dso_name, u64 addr,
 155                      char **file, unsigned int *line, struct dso *dso,
 156                      bool unwind_inlines)
 157 {
 158         int ret = 0;
 159         struct a2l_data *a2l = dso->a2l;
 160
 161         if (!a2l) {
 162                 dso->a2l = addr2line_init(dso_name);
 163                 a2l = dso->a2l;
 164         }
 165
 166         if (a2l == NULL) {
 167                 pr_warning("addr2line_init failed for %s\n", dso_name);
 168                 return 0;
 169         }
 170
 171         a2l->addr = addr;
 172         a2l->found = false;
 173
 174         bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);
 175
 176         if (a2l->found && unwind_inlines) {
 177                 int cnt = 0;
 178
 179                 while (bfd_find_inliner_info(a2l->abfd, &a2l->filename,
 180                                              &a2l->funcname, &a2l->line) &&
 181                        cnt++ < MAX_INLINE_NEST)
 182                         ;
 183         }
 184
 185         if (a2l->found && a2l->filename) {
 186                 *file = strdup(a2l->filename);
 187                 *line = a2l->line;
 188
 189                 if (*file)
 190                         ret = 1;
 191         }
 192
 193         return ret;
 194 }
 195
 196 void dso__free_a2l(struct dso *dso)
 197 {
 198         struct a2l_data *a2l = dso->a2l;
 199
 200         if (!a2l)
 201                 return;
 202
 203         addr2line_cleanup(a2l);
 204
 205         dso->a2l = NULL;
 206 }
 207
 208 #else /* HAVE_LIBBFD_SUPPORT */
 209
 210 static int addr2line(const char *dso_name, u64 addr,
 211                      char **file, unsigned int *line_nr,
 212                      struct dso *dso __maybe_unused,
 213                      bool unwind_inlines __maybe_unused)
 214 {
 215         FILE *fp;
 216         char cmd[PATH_MAX];
 217         char *filename = NULL;
 218         size_t len;
 219         char *sep;
 220         int ret = 0;
 221
 222         scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64,
 223                   dso_name, addr);
 224
 225         fp = popen(cmd, "r");
 226         if (fp == NULL) {
 227                 pr_warning("popen failed for %s\n", dso_name);
 228                 return 0;
 229         }
 230
 231         if (getline(&filename, &len, fp) < 0 || !len) {
 232                 pr_warning("addr2line has no output for %s\n", dso_name);
 233                 goto out;
 234         }
 235
 236         sep = strchr(filename, '\n');
 237         if (sep)
 238                 *sep = '\0';
 239
 240         if (!strcmp(filename, "??:0")) {
 241                 pr_debug("no debugging info in %s\n", dso_name);
 242                 free(filename);
 243                 goto out;
 244         }
 245
 246         sep = strchr(filename, ':');
 247         if (sep) {
 248                 *sep++ = '\0';
 249                 *file = filename;
 250                 *line_nr = strtoul(sep, NULL, 0);
 251                 ret = 1;
 252         }
 253 out:
 254         pclose(fp);
 255         return ret;
 256 }
 257
 258 void dso__free_a2l(struct dso *dso __maybe_unused)
 259 {
 260 }
 261
 262 #endif /* HAVE_LIBBFD_SUPPORT */
 263
 264 /*
 265  * Number of addr2line failures (without success) before disabling it for that
 266  * dso.
 267  */
 268 #define A2L_FAIL_LIMIT 123
 269
 270 char *__get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 271                   bool show_sym, bool unwind_inlines)
 272 {
 273         char *file = NULL;
 274         unsigned line = 0;
 275         char *srcline;
 276         const char *dso_name;
 277
 278         if (!dso->has_srcline)
 279                 goto out;
 280
 281         if (dso->symsrc_filename)
 282                 dso_name = dso->symsrc_filename;
 283         else
 284                 dso_name = dso->long_name;
 285
 286         if (dso_name[0] == '[')
 287                 goto out;
 288
 289         if (!strncmp(dso_name, "/tmp/perf-", 10))
 290                 goto out;
 291
 292         if (!addr2line(dso_name, addr, &file, &line, dso, unwind_inlines))
 293                 goto out;
 294
 295         if (asprintf(&srcline, "%s:%u",
 296                                 srcline_full_filename ? file : basename(file),
 297                                 line) < 0) {
 298                 free(file);
 299                 goto out;
 300         }
 301
 302         dso->a2l_fails = 0;
 303
 304         free(file);
 305         return srcline;
 306
 307 out:
 308         if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
 309                 dso->has_srcline = 0;
 310                 dso__free_a2l(dso);
 311         }
 312         if (sym) {
 313                 if (asprintf(&srcline, "%s+%" PRIu64, show_sym ? sym->name : "",
 314                                         addr - sym->start) < 0)
 315                         return SRCLINE_UNKNOWN;
 316         } else if (asprintf(&srcline, "%s[%" PRIx64 "]", dso->short_name, addr) < 0)
 317                 return SRCLINE_UNKNOWN;
 318         return srcline;
 319 }
 320
 321 void free_srcline(char *srcline)
 322 {
 323         if (srcline && strcmp(srcline, SRCLINE_UNKNOWN) != 0)
 324                 free(srcline);
 325 }
 326
 327 char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,
 328                   bool show_sym)
 329 {
 330         return __get_srcline(dso, addr, sym, show_sym, false);
 331 }