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             : #include "libdwflP.h"
      30             : 
      31             : static int
      32         104 : found_build_id (Dwfl_Module *mod, bool set,
      33             :                 const void *bits, int len, GElf_Addr vaddr)
      34             : {
      35         104 :   if (!set)
      36             :     /* When checking bits, we do not compare VADDR because the
      37             :        address found in a debuginfo file may not match the main
      38             :        file as modified by prelink.  */
      39          70 :     return 1 + (mod->build_id_len == len
      40          35 :                 && !memcmp (bits, mod->build_id_bits, len));
      41             : 
      42          69 :   void *copy = malloc (len);
      43          69 :   if (unlikely (copy == NULL))
      44             :     {
      45           0 :       __libdwfl_seterrno (DWFL_E_NOMEM);
      46           0 :       return -1;
      47             :     }
      48             : 
      49          69 :   mod->build_id_bits = memcpy (copy, bits, len);
      50          69 :   mod->build_id_vaddr = vaddr;
      51          69 :   mod->build_id_len = len;
      52          69 :   return len;
      53             : }
      54             : 
      55             : int
      56             : internal_function
      57         115 : __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
      58             : {
      59             :   const void *build_id_bits;
      60             :   GElf_Addr build_id_elfaddr;
      61             :   int build_id_len;
      62             : 
      63             :   /* For mod == NULL use dwelf_elf_gnu_build_id directly.  */
      64         115 :   assert (mod != NULL);
      65             : 
      66         115 :   int result = __libdwfl_find_elf_build_id (mod, elf, &build_id_bits,
      67             :                                             &build_id_elfaddr, &build_id_len);
      68         115 :   if (result <= 0)
      69             :     return result;
      70             : 
      71         208 :   GElf_Addr build_id_vaddr = build_id_elfaddr + (build_id_elfaddr != 0
      72         104 :                                                  ? mod->main_bias : 0);
      73         104 :   return found_build_id (mod, set, build_id_bits, build_id_len, build_id_vaddr);
      74             : }
      75             : 
      76             : int
      77         199 : dwfl_module_build_id (Dwfl_Module *mod,
      78             :                       const unsigned char **bits, GElf_Addr *vaddr)
      79             : {
      80         199 :   if (mod == NULL)
      81             :     return -1;
      82             : 
      83         199 :   if (mod->build_id_len == 0 && mod->main.elf != NULL)
      84             :     {
      85             :       /* We have the file, but have not examined it yet.  */
      86          80 :       int result = __libdwfl_find_build_id (mod, true, mod->main.elf);
      87          80 :       if (result <= 0)
      88             :         {
      89          11 :           mod->build_id_len = -1;    /* Cache negative result.  */
      90          11 :           return result;
      91             :         }
      92             :     }
      93             : 
      94         188 :   if (mod->build_id_len <= 0)
      95             :     return 0;
      96             : 
      97         184 :   *bits = mod->build_id_bits;
      98         184 :   *vaddr = mod->build_id_vaddr;
      99         184 :   return mod->build_id_len;
     100             : }
     101             : INTDEF (dwfl_module_build_id)
     102             : NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138)
     103             : 
     104             : #ifdef SYMBOL_VERSIONING
     105             : COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end)
     106             : 
     107             : int
     108             : _compat_vaddr_at_end_dwfl_module_build_id (Dwfl_Module *mod,
     109             :                                            const unsigned char **bits,
     110             :                                            GElf_Addr *vaddr)
     111             : {
     112             :   int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr);
     113             :   if (result > 0)
     114             :     *vaddr += (result + 3) & -4;
     115             :   return result;
     116             : }
     117             : #endif