| 1 | /* simple.c -- BFD simple client routines |
| 2 | Copyright (C) 2002-2020 Free Software Foundation, Inc. |
| 3 | Contributed by MontaVista Software, Inc. |
| 4 | |
| 5 | This file is part of BFD, the Binary File Descriptor library. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 20 | MA 02110-1301, USA. */ |
| 21 | |
| 22 | #include "sysdep.h" |
| 23 | #include "bfd.h" |
| 24 | #include "libbfd.h" |
| 25 | #include "bfdlink.h" |
| 26 | |
| 27 | static void |
| 28 | simple_dummy_warning (struct bfd_link_info *link_info ATTRIBUTE_UNUSED, |
| 29 | const char *warning ATTRIBUTE_UNUSED, |
| 30 | const char *symbol ATTRIBUTE_UNUSED, |
| 31 | bfd *abfd ATTRIBUTE_UNUSED, |
| 32 | asection *section ATTRIBUTE_UNUSED, |
| 33 | bfd_vma address ATTRIBUTE_UNUSED) |
| 34 | { |
| 35 | } |
| 36 | |
| 37 | static void |
| 38 | simple_dummy_undefined_symbol (struct bfd_link_info *link_info ATTRIBUTE_UNUSED, |
| 39 | const char *name ATTRIBUTE_UNUSED, |
| 40 | bfd *abfd ATTRIBUTE_UNUSED, |
| 41 | asection *section ATTRIBUTE_UNUSED, |
| 42 | bfd_vma address ATTRIBUTE_UNUSED, |
| 43 | bfd_boolean fatal ATTRIBUTE_UNUSED) |
| 44 | { |
| 45 | } |
| 46 | |
| 47 | static void |
| 48 | simple_dummy_reloc_overflow (struct bfd_link_info *link_info ATTRIBUTE_UNUSED, |
| 49 | struct bfd_link_hash_entry *entry ATTRIBUTE_UNUSED, |
| 50 | const char *name ATTRIBUTE_UNUSED, |
| 51 | const char *reloc_name ATTRIBUTE_UNUSED, |
| 52 | bfd_vma addend ATTRIBUTE_UNUSED, |
| 53 | bfd *abfd ATTRIBUTE_UNUSED, |
| 54 | asection *section ATTRIBUTE_UNUSED, |
| 55 | bfd_vma address ATTRIBUTE_UNUSED) |
| 56 | { |
| 57 | } |
| 58 | |
| 59 | static void |
| 60 | simple_dummy_reloc_dangerous (struct bfd_link_info *link_info ATTRIBUTE_UNUSED, |
| 61 | const char *message ATTRIBUTE_UNUSED, |
| 62 | bfd *abfd ATTRIBUTE_UNUSED, |
| 63 | asection *section ATTRIBUTE_UNUSED, |
| 64 | bfd_vma address ATTRIBUTE_UNUSED) |
| 65 | { |
| 66 | } |
| 67 | |
| 68 | static void |
| 69 | simple_dummy_unattached_reloc (struct bfd_link_info *link_info ATTRIBUTE_UNUSED, |
| 70 | const char *name ATTRIBUTE_UNUSED, |
| 71 | bfd *abfd ATTRIBUTE_UNUSED, |
| 72 | asection *section ATTRIBUTE_UNUSED, |
| 73 | bfd_vma address ATTRIBUTE_UNUSED) |
| 74 | { |
| 75 | } |
| 76 | |
| 77 | static void |
| 78 | simple_dummy_multiple_definition (struct bfd_link_info *link_info ATTRIBUTE_UNUSED, |
| 79 | struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED, |
| 80 | bfd *nbfd ATTRIBUTE_UNUSED, |
| 81 | asection *nsec ATTRIBUTE_UNUSED, |
| 82 | bfd_vma nval ATTRIBUTE_UNUSED) |
| 83 | { |
| 84 | } |
| 85 | |
| 86 | static void |
| 87 | simple_dummy_einfo (const char *fmt ATTRIBUTE_UNUSED, ...) |
| 88 | { |
| 89 | } |
| 90 | |
| 91 | struct saved_output_info |
| 92 | { |
| 93 | bfd_vma offset; |
| 94 | asection *section; |
| 95 | }; |
| 96 | |
| 97 | struct saved_offsets |
| 98 | { |
| 99 | unsigned int section_count; |
| 100 | struct saved_output_info *sections; |
| 101 | }; |
| 102 | |
| 103 | /* The sections in ABFD may already have output sections and offsets |
| 104 | set if we are here during linking. |
| 105 | |
| 106 | DWARF-2 specifies offsets into debug sections in many cases and |
| 107 | bfd_simple_get_relocated_section_contents is called to relocate |
| 108 | debug info for a single relocatable object file. So we want |
| 109 | offsets relative to that object file's sections, not offsets in the |
| 110 | output file. For that reason, reset a debug section->output_offset |
| 111 | to zero. |
| 112 | |
| 113 | If not called during linking then set section->output_section to |
| 114 | point back to the input section, because output_section must not be |
| 115 | NULL when calling the relocation routines. |
| 116 | |
| 117 | Save the original output offset and section to restore later. */ |
| 118 | |
| 119 | static void |
| 120 | simple_save_output_info (bfd *abfd ATTRIBUTE_UNUSED, |
| 121 | asection *section, |
| 122 | void *ptr) |
| 123 | { |
| 124 | struct saved_offsets *saved_offsets = (struct saved_offsets *) ptr; |
| 125 | struct saved_output_info *output_info; |
| 126 | |
| 127 | output_info = &saved_offsets->sections[section->index]; |
| 128 | output_info->offset = section->output_offset; |
| 129 | output_info->section = section->output_section; |
| 130 | if ((section->flags & SEC_DEBUGGING) != 0 |
| 131 | || section->output_section == NULL) |
| 132 | { |
| 133 | section->output_offset = 0; |
| 134 | section->output_section = section; |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | static void |
| 139 | simple_restore_output_info (bfd *abfd ATTRIBUTE_UNUSED, |
| 140 | asection *section, |
| 141 | void *ptr) |
| 142 | { |
| 143 | struct saved_offsets *saved_offsets = (struct saved_offsets *) ptr; |
| 144 | struct saved_output_info *output_info; |
| 145 | |
| 146 | if (section->index >= saved_offsets->section_count) |
| 147 | return; |
| 148 | |
| 149 | output_info = &saved_offsets->sections[section->index]; |
| 150 | section->output_offset = output_info->offset; |
| 151 | section->output_section = output_info->section; |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | FUNCTION |
| 156 | bfd_simple_relocate_secton |
| 157 | |
| 158 | SYNOPSIS |
| 159 | bfd_byte *bfd_simple_get_relocated_section_contents |
| 160 | (bfd *abfd, asection *sec, bfd_byte *outbuf, asymbol **symbol_table); |
| 161 | |
| 162 | DESCRIPTION |
| 163 | Returns the relocated contents of section @var{sec}. The symbols in |
| 164 | @var{symbol_table} will be used, or the symbols from @var{abfd} if |
| 165 | @var{symbol_table} is NULL. The output offsets for debug sections will |
| 166 | be temporarily reset to 0. The result will be stored at @var{outbuf} |
| 167 | or allocated with @code{bfd_malloc} if @var{outbuf} is @code{NULL}. |
| 168 | |
| 169 | Returns @code{NULL} on a fatal error; ignores errors applying |
| 170 | particular relocations. |
| 171 | */ |
| 172 | |
| 173 | bfd_byte * |
| 174 | bfd_simple_get_relocated_section_contents (bfd *abfd, |
| 175 | asection *sec, |
| 176 | bfd_byte *outbuf, |
| 177 | asymbol **symbol_table) |
| 178 | { |
| 179 | struct bfd_link_info link_info; |
| 180 | struct bfd_link_order link_order; |
| 181 | struct bfd_link_callbacks callbacks; |
| 182 | bfd_byte *contents, *data; |
| 183 | int storage_needed; |
| 184 | struct saved_offsets saved_offsets; |
| 185 | bfd *link_next; |
| 186 | |
| 187 | /* Don't apply relocation on executable and shared library. See |
| 188 | PR 4756. */ |
| 189 | if ((abfd->flags & (HAS_RELOC | EXEC_P | DYNAMIC)) != HAS_RELOC |
| 190 | || ! (sec->flags & SEC_RELOC)) |
| 191 | { |
| 192 | contents = outbuf; |
| 193 | if (!bfd_get_full_section_contents (abfd, sec, &contents)) |
| 194 | return NULL; |
| 195 | return contents; |
| 196 | } |
| 197 | |
| 198 | /* In order to use bfd_get_relocated_section_contents, we need |
| 199 | to forge some data structures that it expects. */ |
| 200 | |
| 201 | /* Fill in the bare minimum number of fields for our purposes. */ |
| 202 | memset (&link_info, 0, sizeof (link_info)); |
| 203 | link_info.output_bfd = abfd; |
| 204 | link_info.input_bfds = abfd; |
| 205 | link_info.input_bfds_tail = &abfd->link.next; |
| 206 | |
| 207 | link_next = abfd->link.next; |
| 208 | abfd->link.next = NULL; |
| 209 | link_info.hash = _bfd_generic_link_hash_table_create (abfd); |
| 210 | link_info.callbacks = &callbacks; |
| 211 | callbacks.warning = simple_dummy_warning; |
| 212 | callbacks.undefined_symbol = simple_dummy_undefined_symbol; |
| 213 | callbacks.reloc_overflow = simple_dummy_reloc_overflow; |
| 214 | callbacks.reloc_dangerous = simple_dummy_reloc_dangerous; |
| 215 | callbacks.unattached_reloc = simple_dummy_unattached_reloc; |
| 216 | callbacks.multiple_definition = simple_dummy_multiple_definition; |
| 217 | callbacks.einfo = simple_dummy_einfo; |
| 218 | |
| 219 | memset (&link_order, 0, sizeof (link_order)); |
| 220 | link_order.next = NULL; |
| 221 | link_order.type = bfd_indirect_link_order; |
| 222 | link_order.offset = 0; |
| 223 | link_order.size = sec->size; |
| 224 | link_order.u.indirect.section = sec; |
| 225 | |
| 226 | data = NULL; |
| 227 | if (outbuf == NULL) |
| 228 | { |
| 229 | bfd_size_type amt = sec->rawsize > sec->size ? sec->rawsize : sec->size; |
| 230 | data = (bfd_byte *) bfd_malloc (amt); |
| 231 | if (data == NULL) |
| 232 | { |
| 233 | _bfd_generic_link_hash_table_free (abfd); |
| 234 | abfd->link.next = link_next; |
| 235 | return NULL; |
| 236 | } |
| 237 | outbuf = data; |
| 238 | } |
| 239 | |
| 240 | saved_offsets.section_count = abfd->section_count; |
| 241 | saved_offsets.sections = malloc (sizeof (*saved_offsets.sections) |
| 242 | * saved_offsets.section_count); |
| 243 | if (saved_offsets.sections == NULL) |
| 244 | { |
| 245 | free (data); |
| 246 | _bfd_generic_link_hash_table_free (abfd); |
| 247 | abfd->link.next = link_next; |
| 248 | return NULL; |
| 249 | } |
| 250 | bfd_map_over_sections (abfd, simple_save_output_info, &saved_offsets); |
| 251 | |
| 252 | if (symbol_table == NULL) |
| 253 | { |
| 254 | _bfd_generic_link_add_symbols (abfd, &link_info); |
| 255 | |
| 256 | storage_needed = bfd_get_symtab_upper_bound (abfd); |
| 257 | symbol_table = (asymbol **) bfd_malloc (storage_needed); |
| 258 | bfd_canonicalize_symtab (abfd, symbol_table); |
| 259 | } |
| 260 | else |
| 261 | storage_needed = 0; |
| 262 | |
| 263 | contents = bfd_get_relocated_section_contents (abfd, |
| 264 | &link_info, |
| 265 | &link_order, |
| 266 | outbuf, |
| 267 | 0, |
| 268 | symbol_table); |
| 269 | if (contents == NULL) |
| 270 | free (data); |
| 271 | |
| 272 | bfd_map_over_sections (abfd, simple_restore_output_info, &saved_offsets); |
| 273 | free (saved_offsets.sections); |
| 274 | |
| 275 | _bfd_generic_link_hash_table_free (abfd); |
| 276 | abfd->link.next = link_next; |
| 277 | return contents; |
| 278 | } |