src/elf.c

   1 /* bug-buddy bug submitting program
   2  *
   3  * Copyright (C) 2008 - 2010 Fernando Herrera <fherrera@onirica.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18
  19 #include <libelf.h>
  20 #include <gelf.h>
  21 #include <stdio.h>
  22 #include <fcntl.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25
  26 #include <glib.h>
  27
  28 #include <config.h>
  29
  30 #define N_TRIES 3
  31
  32 static gboolean
  33 find_in_debug_path (const char *filename, const char *debug_filename)
  34 {
  35         char *dir;
  36         char *tries[N_TRIES];
  37         gboolean result = FALSE;
  38         int i;
  39
  40         dir = g_path_get_dirname (filename);
  41         tries[0] = g_build_filename (dir, debug_filename, NULL);
  42         tries[1] = g_build_filename (dir, ".debug", debug_filename, NULL);
  43         tries[2] = g_build_filename ("/usr", "lib", "debug", dir, debug_filename, NULL);
  44
  45         g_free (dir);
  46
  47         for (i = 0; i < N_TRIES; ++i) {
  48                 if (g_file_test (tries[i], G_FILE_TEST_EXISTS)) {
  49                         result = TRUE;
  50                         break;
  51                 }
  52         }
  53
  54         for (i = 0; i < N_TRIES; i++)
  55                 g_free (tries [i]);
  56
  57         return result;
  58 }
  59
  60
  61 gboolean
  62 elf_has_debug_symbols (gint pid)
  63 {
  64         gchar *proc_path;
  65         gchar *filename;
  66         int fd;
  67         Elf *elf;
  68         GElf_Ehdr elf_header;
  69         Elf_Scn *section = 0;
  70
  71         if (pid <= 0)
  72                 return FALSE;
  73
  74         if (elf_version (EV_CURRENT) == EV_NONE ) {
  75                 fprintf(stderr, "Elf library out of date!n");
  76                 return FALSE;
  77         }
  78
  79         proc_path = g_strdup_printf ("/proc/%d/exe", pid);
  80         filename = g_file_read_link (proc_path, NULL);
  81         g_free (proc_path);
  82         if (!filename)
  83                 return FALSE;
  84
  85         fd = open (filename, O_RDONLY);
  86
  87         if ((elf = elf_begin (fd, ELF_C_READ, NULL)) == NULL){
  88                 close (fd);
  89                 return FALSE;
  90         }
  91         gelf_getehdr (elf, &elf_header);
  92         while ((section = elf_nextscn (elf, section)) != 0) {
  93                 GElf_Shdr shdr;
  94
  95                 /* Check for stabs debug information */
  96                 if (gelf_getshdr (section, &shdr) != 0) {
  97                         if (shdr.sh_type == SHT_SYMTAB) {
  98                                 elf_end (elf);
  99                                 return TRUE;
 100                         }
 101                 }
 102
 103                 /* Check for .gnu_debuglink separete debug file */
 104                 if (shdr.sh_type == SHT_PROGBITS) {
 105                         char *name = elf_strptr(elf, elf_header.e_shstrndx, shdr.sh_name);
 106                         if (strcmp (name, ".gnu_debuglink") == 0) {
 107                                 Elf_Data *edata;
 108
 109                                 edata = elf_getdata(section, NULL);
 110                                 if (edata != NULL && find_in_debug_path (filename, (const char*) edata->d_buf)) {
 111                                         elf_end (elf);
 112                                         return TRUE;
 113                                 }
 114                         }
 115                 }
 116         }
 117
 118         /* no symtab neither debug file present */
 119         elf_end (elf);
 120         return FALSE;
 121 }