1 /* Align section. 2 Copyright (C) 2002, 2005 Red Hat, Inc. 3 This file is part of elfutils. 4 Written by Ulrich Drepper <drepper (at) 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 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 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
