Line data    Source code

       1             : /* Get ELF header.
       2             :    Copyright (C) 1998, 1999, 2000, 2002, 2015 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             :    Written by Ulrich Drepper <drepper@redhat.com>, 1998.
       5             : 
       6             :    This file is free software; you can redistribute it and/or modify
       7             :    it under the terms of either
       8             : 
       9             :      * the GNU Lesser General Public License as published by the Free
      10             :        Software Foundation; either version 3 of the License, or (at
      11             :        your option) any later version
      12             : 
      13             :    or
      14             : 
      15             :      * the GNU General Public License as published by the Free
      16             :        Software Foundation; either version 2 of the License, or (at
      17             :        your option) any later version
      18             : 
      19             :    or both in parallel, as here.
      20             : 
      21             :    elfutils is distributed in the hope that it will be useful, but
      22             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      23             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      24             :    General Public License for more details.
      25             : 
      26             :    You should have received copies of the GNU General Public License and
      27             :    the GNU Lesser General Public License along with this program.  If
      28             :    not, see <http://www.gnu.org/licenses/>.  */
      29             : 
      30             : #ifdef HAVE_CONFIG_H
      31             : # include <config.h>
      32             : #endif
      33             : 
      34             : #include <libelf.h>
      35             : #include <stddef.h>
      36             : 
      37             : #include "libelfP.h"
      38             : 
      39             : #ifndef LIBELFBITS
      40             : # define LIBELFBITS 32
      41             : #endif
      42             : 
      43             : 
      44             : static ElfW2(LIBELFBITS,Ehdr) *
      45         534 : getehdr_impl (Elf *elf, int wrlock)
      46             : {
      47         534 :   if (elf == NULL)
      48             :     return NULL;
      49             : 
      50         534 :   if (unlikely (elf->kind != ELF_K_ELF))
      51             :     {
      52           0 :       __libelf_seterrno (ELF_E_INVALID_HANDLE);
      53           0 :       return NULL;
      54             :     }
      55             : 
      56         534 :  again:
      57         534 :   if (elf->class == 0)
      58             :     {
      59           0 :       if (!wrlock)
      60             :         {
      61             :           rwlock_unlock (elf->lock);
      62             :           rwlock_wrlock (elf->lock);
      63             :           wrlock = 1;
      64             :           goto again;
      65             :         }
      66           0 :       elf->class = ELFW(ELFCLASS,LIBELFBITS);
      67             :     }
      68         534 :   else if (unlikely (elf->class != ELFW(ELFCLASS,LIBELFBITS)))
      69             :     {
      70           0 :       __libelf_seterrno (ELF_E_INVALID_CLASS);
      71           0 :       return NULL;
      72             :     }
      73             : 
      74         534 :   return elf->state.ELFW(elf,LIBELFBITS).ehdr;
      75             : }
      76             : 
      77             : ElfW2(LIBELFBITS,Ehdr) *
      78             : internal_function
      79         528 : __elfw2(LIBELFBITS,getehdr_wrlock) (Elf *elf)
      80             : {
      81         528 :   return getehdr_impl (elf, 1);
      82             : }
      83             : 
      84             : ElfW2(LIBELFBITS,Ehdr) *
      85           6 : elfw2(LIBELFBITS,getehdr) (Elf *elf)
      86             : {
      87             :   ElfW2(LIBELFBITS,Ehdr) *result;
      88           6 :   if (elf == NULL)
      89             :     return NULL;
      90             : 
      91             :   rwlock_rdlock (elf->lock);
      92           6 :   result = getehdr_impl (elf, 0);
      93             :   rwlock_unlock (elf->lock);
      94             : 
      95           6 :   return result;
      96             : }