src/gelf_getphdr.c

   1 /* Return program header table entry.
   2    Copyright (C) 1998-2010 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 <string.h>
  35 #include <stdbool.h>
  36
  37 #include "libelfP.h"
  38 #include "gelf.h"
  39 #include "elf.h"
  40
  41
  42 GElf_Phdr *
  43 gelf_getphdr (elf, ndx, dst)
  44      Elf *elf;
  45      int ndx;
  46      GElf_Phdr *dst;
  47 {
  48   GElf_Phdr *result = NULL;
  49
  50   if (elf == NULL)
  51     return NULL;
  52
  53   if (unlikely (elf->kind != ELF_K_ELF))
  54     {
  55       __libelf_seterrno (ELF_E_INVALID_HANDLE);
  56       return NULL;
  57     }
  58
  59   if (dst == NULL)
  60     {
  61       __libelf_seterrno (ELF_E_INVALID_OPERAND);
  62       return NULL;
  63     }
  64
  65   rwlock_rdlock (elf->lock);
  66
  67   if (elf->class == ELFCLASS32)
  68     {
  69       /* Copy the elements one-by-one.  */
  70       Elf32_Phdr *phdr = elf->state.elf32.phdr;
  71
  72       if (phdr == NULL)
  73         {
  74           rwlock_unlock (elf->lock);
  75           phdr = INTUSE(elf32_getphdr) (elf);
  76           if (phdr == NULL)
  77             /* The error number is already set.  */
  78             return NULL;
  79           rwlock_rdlock (elf->lock);
  80         }
  81
  82       /* Test whether the index is ok.  */
  83       size_t phnum;
  84       if (ndx >= elf->state.elf32.ehdr->e_phnum
  85           && (elf->state.elf32.ehdr->e_phnum != PN_XNUM
  86               || __elf_getphdrnum_rdlock (elf, &phnum) != 0
  87               || (size_t) ndx >= phnum))
  88         {
  89           __libelf_seterrno (ELF_E_INVALID_INDEX);
  90           goto out;
  91         }
  92
  93       /* We know the result now.  */
  94       result = dst;
  95
  96       /* Now correct the pointer to point to the correct element.  */
  97       phdr += ndx;
  98
  99 #define COPY(Name) result->Name = phdr->Name
 100       COPY (p_type);
 101       COPY (p_offset);
 102       COPY (p_vaddr);
 103       COPY (p_paddr);
 104       COPY (p_filesz);
 105       COPY (p_memsz);
 106       COPY (p_flags);
 107       COPY (p_align);
 108     }
 109   else
 110     {
 111       /* Copy the elements one-by-one.  */
 112       Elf64_Phdr *phdr = elf->state.elf64.phdr;
 113
 114       if (phdr == NULL)
 115         {
 116           rwlock_unlock (elf->lock);
 117           phdr = INTUSE(elf64_getphdr) (elf);
 118           if (phdr == NULL)
 119             /* The error number is already set.  */
 120             return NULL;
 121           rwlock_rdlock (elf->lock);
 122         }
 123
 124       /* Test whether the index is ok.  */
 125       size_t phnum;
 126       if (ndx >= elf->state.elf64.ehdr->e_phnum
 127           && (elf->state.elf64.ehdr->e_phnum != PN_XNUM
 128               || __elf_getphdrnum_rdlock (elf, &phnum) != 0
 129               || (size_t) ndx >= phnum))
 130         {
 131           __libelf_seterrno (ELF_E_INVALID_INDEX);
 132           goto out;
 133         }
 134
 135       /* We only have to copy the data.  */
 136       result = memcpy (dst, phdr + ndx, sizeof (GElf_Phdr));
 137     }
 138
 139  out:
 140   rwlock_unlock (elf->lock);
 141
 142   return result;
 143 }