xref: /external/elfutils/libdwfl/dwfl_build_id_find_debuginfo.c

/* Find the debuginfo file for a module from its build ID.
   Copyright (C) 2007 Red Hat, Inc.
   This file is part of Red Hat elfutils.

   Red Hat elfutils is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by the
   Free Software Foundation; version 2 of the License.

   Red Hat elfutils is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License along
   with Red Hat elfutils; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.

   In addition, as a special exception, Red Hat, Inc. gives You the
   additional right to link the code of Red Hat elfutils with code licensed
   under any Open Source Initiative certified open source license
   (http://www.opensource.org/licenses/index.php) which requires the
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   this file solely under the GPL without exception.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
   Open Invention Network licensees cross-license their patents.  No patent
   license is granted, either expressly or impliedly, by designation as an
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#include "libdwflP.h"
#include <unistd.h>


int
dwfl_build_id_find_debuginfo (Dwfl_Module *mod,
			      void **userdata __attribute__ ((unused)),
			      const char *modname __attribute__ ((unused)),
			      Dwarf_Addr base __attribute__ ((unused)),
			      const char *file __attribute__ ((unused)),
			      const char *debuglink __attribute__ ((unused)),
			      GElf_Word crc __attribute__ ((unused)),
			      char **debuginfo_file_name)
{
  int fd = -1;
  const unsigned char *bits;
  GElf_Addr vaddr;
  if (INTUSE(dwfl_module_build_id) (mod, &bits, &vaddr) > 0)
    fd = __libdwfl_open_by_build_id (mod, true, debuginfo_file_name);
  if (fd >= 0)
    {
      /* We need to open an Elf handle on the file so we can check its
	 build ID note for validation.  Backdoor the handle into the
	 module data structure since we had to open it early anyway.  */
      mod->debug.elf = elf_begin (fd, ELF_C_READ_MMAP_PRIVATE, NULL);
      if (likely (__libdwfl_find_build_id (mod, false, mod->debug.elf) == 2))
	/* Also backdoor the gratuitous flag.  */
	mod->debug.valid = true;
      else
	{
	  /* A mismatch!  */
	  elf_end (mod->debug.elf);
	  mod->debug.elf = NULL;
	  close (fd);
	  fd = -1;
	  free (*debuginfo_file_name);
	  *debuginfo_file_name = NULL;
	  errno = 0;
	}
    }
  return fd;
}
INTDEF (dwfl_build_id_find_debuginfo)