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