Line data Source code
1 : /* Return number of program headers in the ELF file.
2 : Copyright (C) 2010, 2014, 2015, 2016 Red Hat, Inc.
3 : This file is part of elfutils.
4 :
5 : This file is free software; you can redistribute it and/or modify
6 : it under the terms of either
7 :
8 : * the GNU Lesser General Public License as published by the Free
9 : Software Foundation; either version 3 of the License, or (at
10 : your option) any later version
11 :
12 : or
13 :
14 : * the GNU General Public License as published by the Free
15 : Software Foundation; either version 2 of the License, or (at
16 : your option) any later version
17 :
18 : or both in parallel, as here.
19 :
20 : elfutils is distributed in the hope that it will be useful, but
21 : WITHOUT ANY WARRANTY; without even the implied warranty of
22 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 : General Public License for more details.
24 :
25 : You should have received copies of the GNU General Public License and
26 : the GNU Lesser General Public License along with this program. If
27 : not, see <http://www.gnu.org/licenses/>. */
28 :
29 : #ifdef HAVE_CONFIG_H
30 : # include <config.h>
31 : #endif
32 :
33 : #include <assert.h>
34 : #include <gelf.h>
35 : #include <stddef.h>
36 :
37 : #include "libelfP.h"
38 :
39 :
40 : int
41 : internal_function
42 70683 : __elf_getphdrnum_rdlock (Elf *elf, size_t *dst)
43 : {
44 70683 : if (unlikely (elf->state.elf64.ehdr == NULL))
45 : {
46 : /* Maybe no ELF header was created yet. */
47 0 : __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
48 0 : return -1;
49 : }
50 :
51 141366 : *dst = (elf->class == ELFCLASS32
52 13645 : ? elf->state.elf32.ehdr->e_phnum
53 70683 : : elf->state.elf64.ehdr->e_phnum);
54 :
55 70683 : if (*dst == PN_XNUM)
56 : {
57 0 : const Elf_ScnList *const scns = (elf->class == ELFCLASS32
58 : ? &elf->state.elf32.scns
59 : : &elf->state.elf64.scns);
60 :
61 : /* If there are no section headers, perhaps this is really just 65536
62 : written without PN_XNUM support. Either that or it's bad data. */
63 :
64 0 : if (elf->class == ELFCLASS32)
65 : {
66 0 : if (likely (scns->cnt > 0
67 : && elf->state.elf32.scns.data[0].shdr.e32 != NULL))
68 0 : *dst = scns->data[0].shdr.e32->sh_info;
69 : }
70 : else
71 : {
72 0 : if (likely (scns->cnt > 0
73 : && elf->state.elf64.scns.data[0].shdr.e64 != NULL))
74 0 : *dst = scns->data[0].shdr.e64->sh_info;
75 : }
76 : }
77 :
78 : return 0;
79 : }
80 :
81 : int
82 : internal_function
83 62939 : __elf_getphdrnum_chk_rdlock (Elf *elf, size_t *dst)
84 : {
85 62939 : int result = __elf_getphdrnum_rdlock (elf, dst);
86 :
87 : /* If the phdrs haven't been created or read in yet then do some
88 : sanity checking to make sure phnum and phoff are consistent. */
89 62939 : if (elf->state.elf.phdr == NULL)
90 : {
91 15284 : Elf64_Off off = (elf->class == ELFCLASS32
92 763 : ? elf->state.elf32.ehdr->e_phoff
93 7642 : : elf->state.elf64.ehdr->e_phoff);
94 7642 : if (unlikely (off == 0))
95 : {
96 1223 : *dst = 0;
97 1223 : return result;
98 : }
99 :
100 6419 : if (unlikely (off >= elf->maximum_size))
101 : {
102 0 : __libelf_seterrno (ELF_E_INVALID_DATA);
103 0 : return -1;
104 : }
105 :
106 : /* Check for too many sections. */
107 12838 : size_t phdr_size = (elf->class == ELFCLASS32
108 6419 : ? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr));
109 6419 : if (unlikely (*dst > SIZE_MAX / phdr_size))
110 : {
111 0 : __libelf_seterrno (ELF_E_INVALID_DATA);
112 0 : return -1;
113 : }
114 :
115 : /* Truncated file? Don't return more than can be indexed. */
116 6419 : if (unlikely (elf->maximum_size - off < *dst * phdr_size))
117 0 : *dst = (elf->maximum_size - off) / phdr_size;
118 : }
119 :
120 : return result;
121 : }
122 :
123 : int
124 8660 : elf_getphdrnum (Elf *elf, size_t *dst)
125 : {
126 8660 : int result;
127 :
128 8660 : if (elf == NULL)
129 : return -1;
130 :
131 8660 : if (unlikely (elf->kind != ELF_K_ELF))
132 : {
133 0 : __libelf_seterrno (ELF_E_INVALID_HANDLE);
134 0 : return -1;
135 : }
136 :
137 8660 : rwlock_rdlock (elf->lock);
138 8660 : result = __elf_getphdrnum_chk_rdlock (elf, dst);
139 8660 : rwlock_unlock (elf->lock);
140 :
141 8660 : return result;
142 : }
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