1 /* Align section.
2 Copyright (C) 2002, 2005 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2002.
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 <inttypes.h>
35 #include <stdlib.h>
36 #include <sys/param.h>
37
38 #include <libasmP.h>
39 #include <system.h>
40
41
42 int
asm_align(asmscn,value)43 asm_align (asmscn, value)
44 AsmScn_t *asmscn;
45 GElf_Word value;
46 {
47 if (asmscn == NULL)
48 /* An earlier error. */
49 return -1;
50
51 /* The alignment value must be a power of two. */
52 if (unlikely (! powerof2 (value)))
53 {
54 __libasm_seterrno (ASM_E_INVALID);
55 return -1;
56 }
57
58 if (unlikely (asmscn->ctx->textp))
59 {
60 fprintf (asmscn->ctx->out.file, "\t.align %" PRId32 ", ",
61 (int32_t) value);
62 if (asmscn->pattern->len == 1)
63 fprintf (asmscn->ctx->out.file, "%02hhx\n", asmscn->pattern->bytes[0]);
64 else
65 {
66 fputc_unlocked ('"', asmscn->ctx->out.file);
67
68 for (size_t cnt = 0; cnt < asmscn->pattern->len; ++cnt)
69 fprintf (asmscn->ctx->out.file, "\\x%02hhx",
70 asmscn->pattern->bytes[cnt]);
71
72 fputs_unlocked ("\"\n", asmscn->ctx->out.file);
73 }
74 return 0;
75 }
76
77 rwlock_wrlock (asmscn->ctx->lock);
78
79 int result = 0;
80
81 /* Fillbytes necessary? */
82 if ((asmscn->offset & (value - 1)) != 0)
83 {
84 /* Add fillbytes. */
85 size_t cnt = value - (asmscn->offset & (value - 1));
86
87 /* Ensure there is enough room to add the fill bytes. */
88 result = __libasm_ensure_section_space (asmscn, cnt);
89 if (result != 0)
90 goto out;
91
92 /* Fill in the bytes. We align the pattern according to the
93 current offset. */
94 size_t byteptr = asmscn->offset % asmscn->pattern->len;
95
96 /* Update the total size. */
97 asmscn->offset += cnt;
98
99 do
100 {
101 asmscn->content->data[asmscn->content->len++]
102 = asmscn->pattern->bytes[byteptr++];
103
104 if (byteptr == asmscn->pattern->len)
105 byteptr = 0;
106 }
107 while (--cnt > 0);
108 }
109
110 /* Remember the maximum alignment for this subsection. */
111 if (asmscn->max_align < value)
112 {
113 asmscn->max_align = value;
114
115 /* Update the parent as well (if it exists). */
116 if (asmscn->subsection_id != 0)
117 {
118 rwlock_wrlock (asmscn->data.up->ctx->lock);
119
120 if (asmscn->data.up->max_align < value)
121 asmscn->data.up->max_align = value;
122
123 rwlock_unlock (asmscn->data.up->ctx->lock);
124 }
125 }
126
127 out:
128 rwlock_unlock (asmscn->ctx->lock);
129
130 return result;
131 }
132
133
134 /* Ensure there are at least LEN bytes available in the output buffer
135 for ASMSCN. */
136 int
__libasm_ensure_section_space(asmscn,len)137 __libasm_ensure_section_space (asmscn, len)
138 AsmScn_t *asmscn;
139 size_t len;
140 {
141 /* The blocks with the section content are kept in a circular
142 single-linked list. */
143 size_t size;
144
145 if (asmscn->content == NULL)
146 {
147 /* This is the first block. */
148 size = MAX (2 * len, 960);
149
150 asmscn->content = (struct AsmData *) malloc (sizeof (struct AsmData)
151 + size);
152 if (asmscn->content == NULL)
153 return -1;
154
155 asmscn->content->next = asmscn->content;
156 }
157 else
158 {
159 struct AsmData *newp;
160
161 if (asmscn->content->maxlen - asmscn->content->len >= len)
162 /* Nothing to do, there is enough space. */
163 return 0;
164
165 size = MAX (2 *len, MIN (32768, 2 * asmscn->offset));
166
167 newp = (struct AsmData *) malloc (sizeof (struct AsmData) + size);
168 if (newp == NULL)
169 return -1;
170
171 newp->next = asmscn->content->next;
172 asmscn->content = asmscn->content->next = newp;
173 }
174
175 asmscn->content->len = 0;
176 asmscn->content->maxlen = size;
177
178 return 0;
179 }
180