Line data    Source code

       1             : /* Return build ID information for a module.
       2             :    Copyright (C) 2007-2010, 2014 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             : 
       5             :    This file is free software; you can redistribute it and/or modify
       6             :    it under the terms of either
       7             : 
       8             :      * the GNU Lesser General Public License as published by the Free
       9             :        Software Foundation; either version 3 of the License, or (at
      10             :        your option) any later version
      11             : 
      12             :    or
      13             : 
      14             :      * the GNU General Public License as published by the Free
      15             :        Software Foundation; either version 2 of the License, or (at
      16             :        your option) any later version
      17             : 
      18             :    or both in parallel, as here.
      19             : 
      20             :    elfutils is distributed in the hope that it will be useful, but
      21             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23             :    General Public License for more details.
      24             : 
      25             :    You should have received copies of the GNU General Public License and
      26             :    the GNU Lesser General Public License along with this program.  If
      27             :    not, see <http://www.gnu.org/licenses/>.  */
      28             : 
      29             : #ifdef HAVE_CONFIG_H
      30             : # include <config.h>
      31             : #endif
      32             : 
      33             : #include "libdwflP.h"
      34             : 
      35             : static int
      36         104 : found_build_id (Dwfl_Module *mod, bool set,
      37             :                 const void *bits, int len, GElf_Addr vaddr)
      38             : {
      39         104 :   if (!set)
      40             :     /* When checking bits, we do not compare VADDR because the
      41             :        address found in a debuginfo file may not match the main
      42             :        file as modified by prelink.  */
      43          70 :     return 1 + (mod->build_id_len == len
      44          35 :                 && !memcmp (bits, mod->build_id_bits, len));
      45             : 
      46          69 :   void *copy = malloc (len);
      47          69 :   if (unlikely (copy == NULL))
      48             :     {
      49           0 :       __libdwfl_seterrno (DWFL_E_NOMEM);
      50           0 :       return -1;
      51             :     }
      52             : 
      53          69 :   mod->build_id_bits = memcpy (copy, bits, len);
      54          69 :   mod->build_id_vaddr = vaddr;
      55          69 :   mod->build_id_len = len;
      56          69 :   return len;
      57             : }
      58             : 
      59             : int
      60             : internal_function
      61         115 : __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
      62             : {
      63             :   const void *build_id_bits;
      64             :   GElf_Addr build_id_elfaddr;
      65             :   int build_id_len;
      66             : 
      67             :   /* For mod == NULL use dwelf_elf_gnu_build_id directly.  */
      68         115 :   assert (mod != NULL);
      69             : 
      70         115 :   int result = __libdwfl_find_elf_build_id (mod, elf, &build_id_bits,
      71             :                                             &build_id_elfaddr, &build_id_len);
      72         115 :   if (result <= 0)
      73             :     return result;
      74             : 
      75         208 :   GElf_Addr build_id_vaddr = build_id_elfaddr + (build_id_elfaddr != 0
      76         104 :                                                  ? mod->main_bias : 0);
      77         104 :   return found_build_id (mod, set, build_id_bits, build_id_len, build_id_vaddr);
      78             : }
      79             : 
      80             : int
      81         201 : dwfl_module_build_id (Dwfl_Module *mod,
      82             :                       const unsigned char **bits, GElf_Addr *vaddr)
      83             : {
      84         201 :   if (mod == NULL)
      85             :     return -1;
      86             : 
      87         201 :   if (mod->build_id_len == 0 && mod->main.elf != NULL)
      88             :     {
      89             :       /* We have the file, but have not examined it yet.  */
      90          80 :       int result = __libdwfl_find_build_id (mod, true, mod->main.elf);
      91          80 :       if (result <= 0)
      92             :         {
      93          11 :           mod->build_id_len = -1;    /* Cache negative result.  */
      94          11 :           return result;
      95             :         }
      96             :     }
      97             : 
      98         190 :   if (mod->build_id_len <= 0)
      99             :     return 0;
     100             : 
     101         186 :   *bits = mod->build_id_bits;
     102         186 :   *vaddr = mod->build_id_vaddr;
     103         186 :   return mod->build_id_len;
     104             : }
     105             : INTDEF (dwfl_module_build_id)
     106             : NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138)
     107             : 
     108             : #ifdef SYMBOL_VERSIONING
     109             : COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end)
     110             : 
     111             : int
     112             : _compat_vaddr_at_end_dwfl_module_build_id (Dwfl_Module *mod,
     113             :                                            const unsigned char **bits,
     114             :                                            GElf_Addr *vaddr)
     115             : {
     116             :   int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr);
     117             :   if (result > 0)
     118             :     *vaddr += (result + 3) & -4;
     119             :   return result;
     120             : }
     121             : #endif