1/* Return program header table entry.
2   Copyright (C) 1998-2010 Red Hat, Inc.
3   This file is part of Red Hat elfutils.
4   Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5
6   Red Hat elfutils is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by the
8   Free Software Foundation; version 2 of the License.
9
10   Red Hat elfutils is distributed in the hope that it will be useful, but
11   WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   General Public License for more details.
14
15   You should have received a copy of the GNU General Public License along
16   with Red Hat elfutils; if not, write to the Free Software Foundation,
17   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18
19   In addition, as a special exception, Red Hat, Inc. gives You the
20   additional right to link the code of Red Hat elfutils with code licensed
21   under any Open Source Initiative certified open source license
22   (http://www.opensource.org/licenses/index.php) which requires the
23   distribution of source code with any binary distribution and to
24   distribute linked combinations of the two.  Non-GPL Code permitted under
25   this exception must only link to the code of Red Hat elfutils through
26   those well defined interfaces identified in the file named EXCEPTION
27   found in the source code files (the "Approved Interfaces").  The files
28   of Non-GPL Code may instantiate templates or use macros or inline
29   functions from the Approved Interfaces without causing the resulting
30   work to be covered by the GNU General Public License.  Only Red Hat,
31   Inc. may make changes or additions to the list of Approved Interfaces.
32   Red Hat's grant of this exception is conditioned upon your not adding
33   any new exceptions.  If you wish to add a new Approved Interface or
34   exception, please contact Red Hat.  You must obey the GNU General Public
35   License in all respects for all of the Red Hat elfutils code and other
36   code used in conjunction with Red Hat elfutils except the Non-GPL Code
37   covered by this exception.  If you modify this file, you may extend this
38   exception to your version of the file, but you are not obligated to do
39   so.  If you do not wish to provide this exception without modification,
40   you must delete this exception statement from your version and license
41   this file solely under the GPL without exception.
42
43   Red Hat elfutils is an included package of the Open Invention Network.
44   An included package of the Open Invention Network is a package for which
45   Open Invention Network licensees cross-license their patents.  No patent
46   license is granted, either expressly or impliedly, by designation as an
47   included package.  Should you wish to participate in the Open Invention
48   Network licensing program, please visit www.openinventionnetwork.com
49   <http://www.openinventionnetwork.com>.  */
50
51#ifdef HAVE_CONFIG_H
52# include <config.h>
53#endif
54
55#include <gelf.h>
56#include <string.h>
57#include <stdbool.h>
58
59#include "libelfP.h"
60
61
62GElf_Phdr *
63gelf_getphdr (elf, ndx, dst)
64     Elf *elf;
65     int ndx;
66     GElf_Phdr *dst;
67{
68  GElf_Phdr *result = NULL;
69
70  if (elf == NULL)
71    return NULL;
72
73  if (unlikely (elf->kind != ELF_K_ELF))
74    {
75      __libelf_seterrno (ELF_E_INVALID_HANDLE);
76      return NULL;
77    }
78
79  if (dst == NULL)
80    {
81      __libelf_seterrno (ELF_E_INVALID_OPERAND);
82      return NULL;
83    }
84
85  rwlock_rdlock (elf->lock);
86
87  if (elf->class == ELFCLASS32)
88    {
89      /* Copy the elements one-by-one.  */
90      Elf32_Phdr *phdr = elf->state.elf32.phdr;
91
92      if (phdr == NULL)
93	{
94	  rwlock_unlock (elf->lock);
95	  phdr = INTUSE(elf32_getphdr) (elf);
96	  if (phdr == NULL)
97	    /* The error number is already set.  */
98	    return NULL;
99	  rwlock_rdlock (elf->lock);
100	}
101
102      /* Test whether the index is ok.  */
103      size_t phnum;
104      if (ndx >= elf->state.elf32.ehdr->e_phnum
105	  && (elf->state.elf32.ehdr->e_phnum != PN_XNUM
106	      || __elf_getphdrnum_rdlock (elf, &phnum) != 0
107	      || (size_t) ndx >= phnum))
108	{
109	  __libelf_seterrno (ELF_E_INVALID_INDEX);
110	  goto out;
111	}
112
113      /* We know the result now.  */
114      result = dst;
115
116      /* Now correct the pointer to point to the correct element.  */
117      phdr += ndx;
118
119#define COPY(Name) result->Name = phdr->Name
120      COPY (p_type);
121      COPY (p_offset);
122      COPY (p_vaddr);
123      COPY (p_paddr);
124      COPY (p_filesz);
125      COPY (p_memsz);
126      COPY (p_flags);
127      COPY (p_align);
128    }
129  else
130    {
131      /* Copy the elements one-by-one.  */
132      Elf64_Phdr *phdr = elf->state.elf64.phdr;
133
134      if (phdr == NULL)
135	{
136	  rwlock_unlock (elf->lock);
137	  phdr = INTUSE(elf64_getphdr) (elf);
138	  if (phdr == NULL)
139	    /* The error number is already set.  */
140	    return NULL;
141	  rwlock_rdlock (elf->lock);
142	}
143
144      /* Test whether the index is ok.  */
145      size_t phnum;
146      if (ndx >= elf->state.elf64.ehdr->e_phnum
147	  && (elf->state.elf64.ehdr->e_phnum != PN_XNUM
148	      || __elf_getphdrnum_rdlock (elf, &phnum) != 0
149	      || (size_t) ndx >= phnum))
150	{
151	  __libelf_seterrno (ELF_E_INVALID_INDEX);
152	  goto out;
153	}
154
155      /* We only have to copy the data.  */
156      result = memcpy (dst, phdr + ndx, sizeof (GElf_Phdr));
157    }
158
159 out:
160  rwlock_unlock (elf->lock);
161
162  return result;
163}
164