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

/* Recover relocatibility for addresses computed from debug information.
   Copyright (C) 2005, 2006 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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
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   this exception must only link to the code of Red Hat elfutils through
   those well defined interfaces identified in the file named EXCEPTION
   found in the source code files (the "Approved Interfaces").  The files
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   Inc. may make changes or additions to the list of Approved Interfaces.
   Red Hat's grant of this exception is conditioned upon your not adding
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   exception, please contact Red Hat.  You must obey the GNU General Public
   License in all respects for all of the Red Hat elfutils code and other
   code used in conjunction with Red Hat elfutils except the Non-GPL Code
   covered by this exception.  If you modify this file, you may extend this
   exception to your version of the file, but you are not obligated to do
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   you must delete this exception statement from your version and license
   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>

/* Since dwfl_report_elf lays out the sections already, this will only be
   called when the section headers of the debuginfo file are being
   consulted instead.  With binutils strip-to-debug, the symbol table
   is in the debuginfo file and relocation looks there.  */
int
dwfl_offline_section_address (Dwfl_Module *mod,
			      void **userdata __attribute__ ((unused)),
			      const char *modname __attribute__ ((unused)),
			      Dwarf_Addr base __attribute__ ((unused)),
			      const char *secname __attribute__ ((unused)),
			      Elf32_Word shndx,
			      const GElf_Shdr *shdr __attribute__ ((unused)),
			      Dwarf_Addr *addr)
{
  assert (mod->symfile != &mod->main);

  GElf_Shdr shdr_mem;
  GElf_Shdr *main_shdr = gelf_getshdr (elf_getscn (mod->main.elf, shndx),
				       &shdr_mem);
  if (unlikely (main_shdr == NULL))
    return -1;

  assert (shdr->sh_addr == 0);
  assert (shdr->sh_flags & SHF_ALLOC);
  assert (main_shdr->sh_addr != 0);
  assert (main_shdr->sh_flags == shdr->sh_flags);

  *addr = main_shdr->sh_addr;
  return 0;
}
INTDEF (dwfl_offline_section_address)

Dwfl_Module *
dwfl_report_offline (Dwfl *dwfl, const char *name,
		     const char *file_name, int fd)
{
  if (dwfl == NULL)
    return NULL;

  Dwfl_Module *mod = INTUSE(dwfl_report_elf) (dwfl, name, file_name, fd,
					      dwfl->offline_next_address);
  if (mod != NULL)
    {
      /* If this is an ET_EXEC file with fixed addresses, the address range
	 it consumed may or may not intersect with the arbitrary range we
	 will use for relocatable modules.  Make sure we always use a free
	 range for the offline allocations.  If this module did use
	 offline_next_address, it may have rounded it up for the module's
	 alignment requirements.  */
      if ((dwfl->offline_next_address >= mod->low_addr
	   || mod->low_addr - dwfl->offline_next_address < OFFLINE_REDZONE)
	  && dwfl->offline_next_address < mod->high_addr + OFFLINE_REDZONE)
	dwfl->offline_next_address = mod->high_addr + OFFLINE_REDZONE;

      /* Don't keep the file descriptor around.  */
      if (mod->main.fd != -1 && elf_cntl (mod->main.elf, ELF_C_FDREAD) == 0)
	{
	  close (mod->main.fd);
	  mod->main.fd = -1;
	}
    }

  return mod;
}
INTDEF (dwfl_report_offline)