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