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       1                 :            : /* Find the debuginfo file for a module from its build ID.
       2                 :            :    Copyright (C) 2007, 2009, 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                 :            : int
      36                 :        298 : dwfl_build_id_find_debuginfo (Dwfl_Module *mod,
      37                 :            :                               void **userdata __attribute__ ((unused)),
      38                 :            :                               const char *modname __attribute__ ((unused)),
      39                 :            :                               Dwarf_Addr base __attribute__ ((unused)),
      40                 :            :                               const char *file __attribute__ ((unused)),
      41                 :            :                               const char *debuglink __attribute__ ((unused)),
      42                 :            :                               GElf_Word crc __attribute__ ((unused)),
      43                 :            :                               char **debuginfo_file_name)
      44                 :            : {
      45                 :        298 :   int fd = -1;
      46                 :            : 
      47                 :            :   /* Are we looking for a separate debug file for the main file or for
      48                 :            :      an alternate (dwz multi) debug file?  Alternatively we could check
      49                 :            :      whether the dwbias == -1.  */
      50         [ +  + ]:        298 :   if (mod->dw != NULL)
      51                 :            :     {
      52                 :         70 :       const void *build_id;
      53                 :         70 :       const char *altname;
      54                 :         70 :       ssize_t build_id_len = INTUSE(dwelf_dwarf_gnu_debugaltlink) (mod->dw,
      55                 :            :                                                                    &altname,
      56                 :            :                                                                    &build_id);
      57         [ +  - ]:         70 :       if (build_id_len > 0)
      58                 :         70 :         fd = __libdwfl_open_by_build_id (mod, true, debuginfo_file_name,
      59                 :            :                                          build_id_len, build_id);
      60                 :            : 
      61         [ -  + ]:         70 :       if (fd >= 0)
      62                 :            :         {
      63                 :            :           /* We need to open an Elf handle on the file so we can check its
      64                 :            :              build ID note for validation.  Backdoor the handle into the
      65                 :            :              module data structure since we had to open it early anyway.  */
      66                 :          0 :           Dwfl_Error error = __libdw_open_file (&fd, &mod->alt_elf,
      67                 :            :                                                 true, false);
      68         [ #  # ]:          0 :           if (error != DWFL_E_NOERROR)
      69                 :          0 :             __libdwfl_seterrno (error);
      70                 :            :           else
      71                 :            :             {
      72                 :          0 :               const void *alt_build_id;
      73                 :          0 :               ssize_t alt_len = INTUSE(dwelf_elf_gnu_build_id) (mod->alt_elf,
      74                 :            :                                                                 &alt_build_id);
      75         [ #  # ]:          0 :               if (alt_len > 0 && alt_len == build_id_len
      76         [ #  # ]:          0 :                   && memcmp (build_id, alt_build_id, alt_len) == 0)
      77                 :          0 :                 return fd;
      78                 :            :               else
      79                 :            :                 {
      80                 :            :                   /* A mismatch!  */
      81                 :          0 :                   elf_end (mod->alt_elf);
      82                 :          0 :                   mod->alt_elf = NULL;
      83                 :          0 :                   close (fd);
      84                 :          0 :                   fd = -1;
      85                 :            :                 }
      86                 :          0 :               free (*debuginfo_file_name);
      87                 :          0 :               *debuginfo_file_name = NULL;
      88                 :          0 :               errno = 0;
      89                 :            :             }
      90                 :            :         }
      91                 :         70 :       return fd;
      92                 :            :     }
      93                 :            : 
      94                 :            :   /* We don't even have the Dwarf yet and it isn't in the main file.
      95                 :            :      Try to find separate debug file now using the module build id.  */
      96                 :        228 :   const unsigned char *bits;
      97                 :        228 :   GElf_Addr vaddr;
      98                 :            : 
      99         [ +  - ]:        228 :   if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0)
     100                 :        228 :     fd = __libdwfl_open_mod_by_build_id (mod, true, debuginfo_file_name);
     101         [ +  + ]:        228 :   if (fd >= 0)
     102                 :            :     {
     103                 :            :       /* We need to open an Elf handle on the file so we can check its
     104                 :            :          build ID note for validation.  Backdoor the handle into the
     105                 :            :          module data structure since we had to open it early anyway.  */
     106                 :         32 :       Dwfl_Error error = __libdw_open_file (&fd, &mod->debug.elf, true, false);
     107         [ -  + ]:         32 :       if (error != DWFL_E_NOERROR)
     108                 :          0 :         __libdwfl_seterrno (error);
     109         [ +  - ]:         32 :       else if (likely (__libdwfl_find_build_id (mod, false,
     110                 :            :                                                 mod->debug.elf) == 2))
     111                 :            :         {
     112                 :            :           /* Also backdoor the gratuitous flag.  */
     113                 :         32 :           mod->debug.valid = true;
     114                 :         32 :           return fd;
     115                 :            :         }
     116                 :            :       else
     117                 :            :         {
     118                 :            :           /* A mismatch!  */
     119                 :          0 :           elf_end (mod->debug.elf);
     120                 :          0 :           mod->debug.elf = NULL;
     121                 :          0 :           close (fd);
     122                 :          0 :           fd = -1;
     123                 :            :         }
     124                 :          0 :       free (*debuginfo_file_name);
     125                 :          0 :       *debuginfo_file_name = NULL;
     126                 :          0 :       errno = 0;
     127                 :            :     }
     128                 :        196 :   return fd;
     129                 :            : }
     130                 :            : INTDEF (dwfl_build_id_find_debuginfo)