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      1 /* Get ELF header.
      2    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2005, 2015 Red Hat, Inc.
      3    This file is part of elfutils.
      4    Written by Ulrich Drepper <drepper (at) 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 <gelf.h>
     35 #include <stddef.h>
     36 #include <stdlib.h>
     37 #include <string.h>
     38 
     39 #include "libelfP.h"
     40 
     41 
     42 GElf_Ehdr *
     43 internal_function
     44 __gelf_getehdr_rdlock (Elf *elf, GElf_Ehdr *dest)
     45 {
     46   GElf_Ehdr *result = NULL;
     47 
     48   if (elf == NULL)
     49     return NULL;
     50 
     51   if (unlikely (elf->kind != ELF_K_ELF))
     52     {
     53       __libelf_seterrno (ELF_E_INVALID_HANDLE);
     54       return NULL;
     55     }
     56 
     57   /* The following is an optimization: the ehdr element is at the same
     58      position in both the elf32 and elf64 structure.  */
     59   if (offsetof (struct Elf, state.elf32.ehdr)
     60       != offsetof (struct Elf, state.elf64.ehdr))
     61     abort ();
     62   /* Just pick one of the values.  */
     63  if (unlikely (elf->state.elf64.ehdr == NULL))
     64     /* Maybe no ELF header was created yet.  */
     65     __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
     66   else if (elf->class == ELFCLASS32)
     67     {
     68       Elf32_Ehdr *ehdr = elf->state.elf32.ehdr;
     69 
     70       /* Convert the 32-bit struct to an 64-bit one.  */
     71       memcpy (dest->e_ident, ehdr->e_ident, EI_NIDENT);
     72 #define COPY(name) \
     73       dest->name = ehdr->name
     74       COPY (e_type);
     75       COPY (e_machine);
     76       COPY (e_version);
     77       COPY (e_entry);
     78       COPY (e_phoff);
     79       COPY (e_shoff);
     80       COPY (e_flags);
     81       COPY (e_ehsize);
     82       COPY (e_phentsize);
     83       COPY (e_phnum);
     84       COPY (e_shentsize);
     85       COPY (e_shnum);
     86       COPY (e_shstrndx);
     87 
     88       result = dest;
     89     }
     90   else
     91     result = memcpy (dest, elf->state.elf64.ehdr, sizeof (*dest));
     92 
     93   return result;
     94 }
     95 
     96 GElf_Ehdr *
     97 gelf_getehdr (Elf *elf, GElf_Ehdr *dest)
     98 {
     99   GElf_Ehdr *result;
    100   if (elf == NULL)
    101     return NULL;
    102 
    103   rwlock_rdlock (elf->lock);
    104   result = __gelf_getehdr_rdlock (elf, dest);
    105   rwlock_unlock (elf->lock);
    106 
    107   return result;
    108 }
    109