Line data Source code
1 : /* Create new ELF program header table.
2 : Copyright (C) 1999-2010, 2014, 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 <assert.h>
35 : #include <stdlib.h>
36 : #include <string.h>
37 :
38 : #include "libelfP.h"
39 :
40 : #ifndef LIBELFBITS
41 : # define LIBELFBITS 32
42 : #endif
43 :
44 :
45 : ElfW2(LIBELFBITS,Phdr) *
46 254 : elfw2(LIBELFBITS,newphdr) (Elf *elf, size_t count)
47 : {
48 : ElfW2(LIBELFBITS,Phdr) *result;
49 :
50 254 : if (elf == NULL)
51 : return NULL;
52 :
53 254 : if (unlikely (elf->kind != ELF_K_ELF))
54 : {
55 0 : __libelf_seterrno (ELF_E_INVALID_HANDLE);
56 0 : return NULL;
57 : }
58 :
59 254 : if (unlikely ((ElfW2(LIBELFBITS,Word)) count != count))
60 : {
61 0 : __libelf_seterrno (ELF_E_INVALID_OPERAND);
62 0 : return NULL;
63 : }
64 :
65 : rwlock_wrlock (elf->lock);
66 :
67 254 : if (elf->class == 0)
68 0 : elf->class = ELFW(ELFCLASS,LIBELFBITS);
69 254 : else if (unlikely (elf->class != ELFW(ELFCLASS,LIBELFBITS)))
70 : {
71 0 : __libelf_seterrno (ELF_E_INVALID_CLASS);
72 0 : result = NULL;
73 0 : goto out;
74 : }
75 :
76 254 : if (unlikely (elf->state.ELFW(elf,LIBELFBITS).ehdr == NULL))
77 : {
78 0 : __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
79 0 : result = NULL;
80 0 : goto out;
81 : }
82 :
83 : /* A COUNT of zero means remove existing table. */
84 254 : if (count == 0)
85 : {
86 : /* Free the old program header. */
87 0 : if (elf->state.ELFW(elf,LIBELFBITS).phdr != NULL)
88 : {
89 0 : if (elf->state.ELFW(elf,LIBELFBITS).phdr_flags & ELF_F_MALLOCED)
90 0 : free (elf->state.ELFW(elf,LIBELFBITS).phdr);
91 :
92 : /* Set the pointer to NULL. */
93 0 : elf->state.ELFW(elf,LIBELFBITS).phdr = NULL;
94 : /* Set the `e_phnum' member to the new value. */
95 0 : elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum = 0;
96 : /* Also clear any old PN_XNUM extended value. */
97 0 : if (elf->state.ELFW(elf,LIBELFBITS).scns.cnt > 0)
98 : elf->state.ELFW(elf,LIBELFBITS).scns.data[0]
99 0 : .shdr.ELFW(e,LIBELFBITS)->sh_info = 0;
100 : /* Also set the size. */
101 0 : elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phentsize =
102 : sizeof (ElfW2(LIBELFBITS,Phdr));
103 :
104 0 : elf->state.ELFW(elf,LIBELFBITS).phdr_flags |= ELF_F_DIRTY;
105 0 : elf->flags |= ELF_F_DIRTY;
106 0 : __libelf_seterrno (ELF_E_NOERROR);
107 : }
108 :
109 : result = NULL;
110 : }
111 254 : else if (elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum != count
112 21 : || count == PN_XNUM
113 21 : || elf->state.ELFW(elf,LIBELFBITS).phdr == NULL)
114 : {
115 243 : if (unlikely (count > SIZE_MAX / sizeof (ElfW2(LIBELFBITS,Phdr))))
116 : {
117 0 : __libelf_seterrno (ELF_E_INVALID_INDEX);
118 0 : result = NULL;
119 0 : goto out;
120 : }
121 :
122 243 : Elf_Scn *scn0 = &elf->state.ELFW(elf,LIBELFBITS).scns.data[0];
123 243 : if (unlikely (count >= PN_XNUM && scn0->shdr.ELFW(e,LIBELFBITS) == NULL))
124 : {
125 : /* Something is wrong with section zero, but we need it to write
126 : the extended phdr count. */
127 0 : __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER);
128 0 : result = NULL;
129 0 : goto out;
130 : }
131 :
132 : /* Allocate a new program header with the appropriate number of
133 : elements. */
134 243 : result = (ElfW2(LIBELFBITS,Phdr) *)
135 243 : realloc (elf->state.ELFW(elf,LIBELFBITS).phdr,
136 : count * sizeof (ElfW2(LIBELFBITS,Phdr)));
137 243 : if (result == NULL)
138 0 : __libelf_seterrno (ELF_E_NOMEM);
139 : else
140 : {
141 : /* Now set the result. */
142 243 : elf->state.ELFW(elf,LIBELFBITS).phdr = result;
143 243 : if (count >= PN_XNUM)
144 : {
145 : /* We have to write COUNT into the zeroth section's sh_info. */
146 0 : if (elf->state.ELFW(elf,LIBELFBITS).scns.cnt == 0)
147 : {
148 0 : assert (elf->state.ELFW(elf,LIBELFBITS).scns.max > 0);
149 0 : elf->state.ELFW(elf,LIBELFBITS).scns.cnt = 1;
150 : }
151 0 : scn0->shdr.ELFW(e,LIBELFBITS)->sh_info = count;
152 0 : scn0->shdr_flags |= ELF_F_DIRTY;
153 0 : elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum = PN_XNUM;
154 : }
155 : else
156 : /* Set the `e_phnum' member to the new value. */
157 243 : elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phnum = count;
158 : /* Clear the whole memory. */
159 243 : memset (result, '\0', count * sizeof (ElfW2(LIBELFBITS,Phdr)));
160 : /* Also set the size. */
161 486 : elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phentsize =
162 243 : elf_typesize (LIBELFBITS, ELF_T_PHDR, 1);
163 : /* Remember we allocated the array and mark the structure is
164 : modified. */
165 243 : elf->state.ELFW(elf,LIBELFBITS).phdr_flags |=
166 : ELF_F_DIRTY | ELF_F_MALLOCED;
167 : /* We have to rewrite the entire file if the size of the
168 : program header is changed. */
169 243 : elf->flags |= ELF_F_DIRTY;
170 : }
171 : }
172 : else
173 : {
174 : /* We have the same number of entries. Just clear the array. */
175 11 : assert (elf->state.ELFW(elf,LIBELFBITS).ehdr->e_phentsize
176 : == elf_typesize (LIBELFBITS, ELF_T_PHDR, 1));
177 :
178 : /* Mark the structure as modified. */
179 11 : elf->state.ELFW(elf,LIBELFBITS).phdr_flags |= ELF_F_DIRTY;
180 :
181 11 : result = elf->state.ELFW(elf,LIBELFBITS).phdr;
182 11 : memset (result, '\0', count * sizeof (ElfW2(LIBELFBITS,Phdr)));
183 : }
184 :
185 : out:
186 : rwlock_unlock (elf->lock);
187 :
188 254 : return result;
189 : }
190 : INTDEF(elfw2(LIBELFBITS,newphdr))
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