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
41 GElf_Phdr *
gelf_getphdr(Elf * elf,int ndx,GElf_Phdr * dst)42 gelf_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