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