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