Line data    Source code

       1             : /* Try to get an ELF or debug file through the debuginfod.
       2             :    Copyright (C) 2019 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             : #include <dlfcn.h>
      35             : 
      36             : static __typeof__ (debuginfod_begin) *fp_debuginfod_begin;
      37             : static __typeof__ (debuginfod_find_executable) *fp_debuginfod_find_executable;
      38             : static __typeof__ (debuginfod_find_debuginfo) *fp_debuginfod_find_debuginfo;
      39             : static __typeof__ (debuginfod_end) *fp_debuginfod_end;
      40             : 
      41             : /* NB: this is slightly thread-unsafe */
      42             : 
      43             : static debuginfod_client *
      44           0 : get_client (Dwfl *dwfl)
      45             : {
      46           0 :   if (dwfl->debuginfod != NULL)
      47           0 :     return dwfl->debuginfod;
      48             : 
      49          71 :   if (fp_debuginfod_begin != NULL)
      50             :     {
      51           0 :       dwfl->debuginfod = (*fp_debuginfod_begin) ();
      52           0 :       return dwfl->debuginfod;
      53             :     }
      54             : 
      55             :   return NULL;
      56             : }
      57             : 
      58             : int
      59          14 : __libdwfl_debuginfod_find_executable (Dwfl *dwfl,
      60             :                                       const unsigned char *build_id_bits,
      61             :                                       size_t build_id_len)
      62             : {
      63          14 :   int fd = -1;
      64          14 :   if (build_id_len > 0)
      65             :     {
      66          14 :       debuginfod_client *c = get_client (dwfl);
      67           0 :       if (c != NULL)
      68           0 :         fd = (*fp_debuginfod_find_executable) (c, build_id_bits,
      69             :                                                build_id_len, NULL);
      70             :     }
      71             : 
      72          14 :   return fd;
      73             : }
      74             : 
      75             : int
      76          57 : __libdwfl_debuginfod_find_debuginfo (Dwfl *dwfl,
      77             :                                      const unsigned char *build_id_bits,
      78             :                                      size_t build_id_len)
      79             : {
      80          57 :   int fd = -1;
      81          57 :   if (build_id_len > 0)
      82             :     {
      83          57 :       debuginfod_client *c = get_client (dwfl);
      84           0 :       if (c != NULL)
      85           0 :         fd = (*fp_debuginfod_find_debuginfo) (c, build_id_bits,
      86             :                                               build_id_len, NULL);
      87             :     }
      88             : 
      89          57 :   return fd;
      90             : }
      91             : 
      92             : void
      93        5571 : __libdwfl_debuginfod_end (debuginfod_client *c)
      94             : {
      95        5571 :   if (c != NULL)
      96           0 :     (*fp_debuginfod_end) (c);
      97        5571 : }
      98             : 
      99             : /* Try to get the libdebuginfod library functions to make sure
     100             :    everything is initialized early.  */
     101             : void __attribute__ ((constructor))
     102         660 : __libdwfl_debuginfod_init (void)
     103             : {
     104         660 :   void *debuginfod_so = dlopen("libdebuginfod-" VERSION ".so", RTLD_LAZY);
     105             : 
     106         660 :   if (debuginfod_so == NULL)
     107         660 :     debuginfod_so = dlopen("libdebuginfod.so", RTLD_LAZY);
     108             : 
     109         660 :   if (debuginfod_so != NULL)
     110             :     {
     111           0 :       fp_debuginfod_begin = dlsym (debuginfod_so, "debuginfod_begin");
     112           0 :       fp_debuginfod_find_executable = dlsym (debuginfod_so,
     113             :                                              "debuginfod_find_executable");
     114           0 :       fp_debuginfod_find_debuginfo = dlsym (debuginfod_so,
     115             :                                             "debuginfod_find_debuginfo");
     116           0 :       fp_debuginfod_end = dlsym (debuginfod_so, "debuginfod_end");
     117             : 
     118             :       /* We either get them all, or we get none.  */
     119           0 :       if (fp_debuginfod_begin == NULL
     120           0 :           || fp_debuginfod_find_executable == NULL
     121           0 :           || fp_debuginfod_find_debuginfo == NULL
     122           0 :           || fp_debuginfod_end == NULL)
     123             :         {
     124           0 :           fp_debuginfod_begin = NULL;
     125           0 :           fp_debuginfod_find_executable = NULL;
     126           0 :           fp_debuginfod_find_debuginfo = NULL;
     127           0 :           fp_debuginfod_end = NULL;
     128           0 :           dlclose (debuginfod_so);
     129             :         }
     130             :     }
     131         660 : }