1 /* Append new section.
2 Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
3 This file is part of Red Hat elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 1998.
5
6 Red Hat elfutils is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by the
8 Free Software Foundation; version 2 of the License.
9
10 Red Hat elfutils is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
14
15 You should have received a copy of the GNU General Public License along
16 with Red Hat elfutils; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
18
19 In addition, as a special exception, Red Hat, Inc. gives You the
20 additional right to link the code of Red Hat elfutils with code licensed
21 under any Open Source Initiative certified open source license
22 (http://www.opensource.org/licenses/index.php) which requires the
23 distribution of source code with any binary distribution and to
24 distribute linked combinations of the two. Non-GPL Code permitted under
25 this exception must only link to the code of Red Hat elfutils through
26 those well defined interfaces identified in the file named EXCEPTION
27 found in the source code files (the "Approved Interfaces"). The files
28 of Non-GPL Code may instantiate templates or use macros or inline
29 functions from the Approved Interfaces without causing the resulting
30 work to be covered by the GNU General Public License. Only Red Hat,
31 Inc. may make changes or additions to the list of Approved Interfaces.
32 Red Hat's grant of this exception is conditioned upon your not adding
33 any new exceptions. If you wish to add a new Approved Interface or
34 exception, please contact Red Hat. You must obey the GNU General Public
35 License in all respects for all of the Red Hat elfutils code and other
36 code used in conjunction with Red Hat elfutils except the Non-GPL Code
37 covered by this exception. If you modify this file, you may extend this
38 exception to your version of the file, but you are not obligated to do
39 so. If you do not wish to provide this exception without modification,
40 you must delete this exception statement from your version and license
41 this file solely under the GPL without exception.
42
43 Red Hat elfutils is an included package of the Open Invention Network.
44 An included package of the Open Invention Network is a package for which
45 Open Invention Network licensees cross-license their patents. No patent
46 license is granted, either expressly or impliedly, by designation as an
47 included package. Should you wish to participate in the Open Invention
48 Network licensing program, please visit www.openinventionnetwork.com
49 <http://www.openinventionnetwork.com>. */
50
51 #ifdef HAVE_CONFIG_H
52 # include <config.h>
53 #endif
54
55 #include <assert.h>
56 #include <stdbool.h>
57 #include <stddef.h>
58 #include <stdlib.h>
59 #include <string.h>
60
61 #include "libelfP.h"
62
63
64 Elf_Scn *
elf_newscn(elf)65 elf_newscn (elf)
66 Elf *elf;
67 {
68 Elf_Scn *result = NULL;
69 bool first = false;
70
71 if (elf == NULL)
72 return NULL;
73
74 /* We rely on the prefix of the `elf', `elf32', and `elf64' element
75 being the same. */
76 assert (offsetof (Elf, state.elf.scns_last)
77 == offsetof (Elf, state.elf32.scns_last));
78 assert (offsetof (Elf, state.elf.scns_last)
79 == offsetof (Elf, state.elf64.scns_last));
80 assert (offsetof (Elf, state.elf32.scns)
81 == offsetof (Elf, state.elf64.scns));
82
83 rwlock_wrlock (elf->lock);
84
85 again:
86 if (elf->state.elf.scns_last->cnt < elf->state.elf.scns_last->max)
87 {
88 result = &elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt];
89
90 if (++elf->state.elf.scns_last->cnt == 1
91 && (elf->state.elf.scns_last
92 == (elf->class == ELFCLASS32
93 || (offsetof (Elf, state.elf32.scns)
94 == offsetof (Elf, state.elf64.scns))
95 ? &elf->state.elf32.scns : &elf->state.elf64.scns)))
96 /* This is zeroth section. */
97 first = true;
98 else
99 {
100 assert (elf->state.elf.scns_last->cnt > 1);
101 result->index = result[-1].index + 1;
102 }
103 }
104 else
105 {
106 /* We must allocate a new element. */
107 Elf_ScnList *newp;
108
109 assert (elf->state.elf.scnincr > 0);
110
111 newp = (Elf_ScnList *) calloc (sizeof (Elf_ScnList)
112 + ((elf->state.elf.scnincr *= 2)
113 * sizeof (Elf_Scn)), 1);
114 if (newp == NULL)
115 {
116 __libelf_seterrno (ELF_E_NOMEM);
117 goto out;
118 }
119
120 result = &newp->data[0];
121
122 /* One section used. */
123 ++newp->cnt;
124
125 /* This is the number of sections we allocated. */
126 newp->max = elf->state.elf.scnincr;
127
128 /* Remember the index for the first section in this block. */
129 newp->data[0].index
130 = 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->max - 1].index;
131
132 /* Enqueue the new list element. */
133 elf->state.elf.scns_last = elf->state.elf.scns_last->next = newp;
134 }
135
136 /* Create a section header for this section. */
137 if (elf->class == ELFCLASS32)
138 {
139 result->shdr.e32 = (Elf32_Shdr *) calloc (1, sizeof (Elf32_Shdr));
140 if (result->shdr.e32 == NULL)
141 {
142 __libelf_seterrno (ELF_E_NOMEM);
143 goto out;
144 }
145 }
146 else
147 {
148 result->shdr.e64 = (Elf64_Shdr *) calloc (1, sizeof (Elf64_Shdr));
149 if (result->shdr.e64 == NULL)
150 {
151 __libelf_seterrno (ELF_E_NOMEM);
152 goto out;
153 }
154 }
155
156 result->elf = elf;
157 result->shdr_flags = ELF_F_DIRTY | ELF_F_MALLOCED;
158 result->list = elf->state.elf.scns_last;
159
160 /* Initialize the data part. */
161 result->data_read = 1;
162 if (unlikely (first))
163 {
164 /* For the first section we mark the data as already available. */
165 //result->data_list_rear = &result->data_list;
166 first = false;
167 goto again;
168 }
169
170 result->flags |= ELF_F_DIRTY;
171
172 out:
173 rwlock_unlock (elf->lock);
174
175 return result;
176 }
177