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                 free((void *)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         free((void *)a2l->input);
 144         free(a2l->syms);
 145         free(a2l);
 146 }
 147
 148 static int addr2line(const char *dso_name, unsigned long addr,
 149                      char **file, unsigned int *line)
 150 {
 151         int ret = 0;
 152         struct a2l_data *a2l;
 153
 154         a2l = addr2line_init(dso_name);
 155         if (a2l == NULL) {
 156                 pr_warning("addr2line_init failed for %s\n", dso_name);
 157                 return 0;
 158         }
 159
 160         a2l->addr = addr;
 161         bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);
 162
 163         if (a2l->found && a2l->filename) {
 164                 *file = strdup(a2l->filename);
 165                 *line = a2l->line;
 166
 167                 if (*file)
 168                         ret = 1;
 169         }
 170
 171         addr2line_cleanup(a2l);
 172         return ret;
 173 }
 174
 175 #else /* HAVE_LIBBFD_SUPPORT */
 176
 177 static int addr2line(const char *dso_name, unsigned long addr,
 178                      char **file, unsigned int *line_nr)
 179 {
 180         FILE *fp;
 181         char cmd[PATH_MAX];
 182         char *filename = NULL;
 183         size_t len;
 184         char *sep;
 185         int ret = 0;
 186
 187         scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64,
 188                   dso_name, addr);
 189
 190         fp = popen(cmd, "r");
 191         if (fp == NULL) {
 192                 pr_warning("popen failed for %s\n", dso_name);
 193                 return 0;
 194         }
 195
 196         if (getline(&filename, &len, fp) < 0 || !len) {
 197                 pr_warning("addr2line has no output for %s\n", dso_name);
 198                 goto out;
 199         }
 200
 201         sep = strchr(filename, '\n');
 202         if (sep)
 203                 *sep = '\0';
 204
 205         if (!strcmp(filename, "??:0")) {
 206                 pr_debug("no debugging info in %s\n", dso_name);
 207                 free(filename);
 208                 goto out;
 209         }
 210
 211         sep = strchr(filename, ':');
 212         if (sep) {
 213                 *sep++ = '\0';
 214                 *file = filename;
 215                 *line_nr = strtoul(sep, NULL, 0);
 216                 ret = 1;
 217         }
 218 out:
 219         pclose(fp);
 220         return ret;
 221 }
 222 #endif /* HAVE_LIBBFD_SUPPORT */
 223
 224 char *get_srcline(struct dso *dso, unsigned long addr)
 225 {
 226         char *file = NULL;
 227         unsigned line = 0;
 228         char *srcline;
 229         char *dso_name = dso->long_name;
 230         size_t size;
 231
 232         if (!dso->has_srcline)
 233                 return SRCLINE_UNKNOWN;
 234
 235         if (dso_name[0] == '[')
 236                 goto out;
 237
 238         if (!strncmp(dso_name, "/tmp/perf-", 10))
 239                 goto out;
 240
 241         if (!addr2line(dso_name, addr, &file, &line))
 242                 goto out;
 243
 244         /* just calculate actual length */
 245         size = snprintf(NULL, 0, "%s:%u", file, line) + 1;
 246
 247         srcline = malloc(size);
 248         if (srcline)
 249                 snprintf(srcline, size, "%s:%u", file, line);
 250         else
 251                 srcline = SRCLINE_UNKNOWN;
 252
 253         free(file);
 254         return srcline;
 255
 256 out:
 257         dso->has_srcline = 0;
 258         return SRCLINE_UNKNOWN;
 259 }
 260
 261 void free_srcline(char *srcline)
 262 {
 263         if (srcline && strcmp(srcline, SRCLINE_UNKNOWN) != 0)
 264                 free(srcline);
 265 }