| 1 | # This shell script emits a C file. -*- C -*- |
| 2 | # Copyright (C) 2009-2020 Free Software Foundation, Inc. |
| 3 | # Contributed by ARM Ltd. |
| 4 | # |
| 5 | # This file is part of the GNU Binutils. |
| 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; see the file COPYING3. If not, |
| 19 | # see <http://www.gnu.org/licenses/>. |
| 20 | # |
| 21 | |
| 22 | # This file is sourced from elf.em, and defines extra aarch64-elf |
| 23 | # specific routines. |
| 24 | # |
| 25 | fragment <<EOF |
| 26 | |
| 27 | #include "ldctor.h" |
| 28 | #include "elf/aarch64.h" |
| 29 | #include "elfxx-aarch64.h" |
| 30 | |
| 31 | static int no_enum_size_warning = 0; |
| 32 | static int no_wchar_size_warning = 0; |
| 33 | static int pic_veneer = 0; |
| 34 | static int fix_erratum_835769 = 0; |
| 35 | static erratum_84319_opts fix_erratum_843419 = ERRAT_NONE; |
| 36 | static int no_apply_dynamic_relocs = 0; |
| 37 | static aarch64_plt_type plt_type = PLT_NORMAL; |
| 38 | static aarch64_enable_bti_type bti_type = BTI_NONE; |
| 39 | |
| 40 | static void |
| 41 | gld${EMULATION_NAME}_before_parse (void) |
| 42 | { |
| 43 | #ifndef TARGET_ /* I.e., if not generic. */ |
| 44 | ldfile_set_output_arch ("`echo ${ARCH}`", bfd_arch_unknown); |
| 45 | #endif /* not TARGET_ */ |
| 46 | input_flags.dynamic = ${DYNAMIC_LINK-TRUE}; |
| 47 | config.has_shared = `if test -n "$GENERATE_SHLIB_SCRIPT" ; then echo TRUE ; else echo FALSE ; fi`; |
| 48 | config.separate_code = `if test "x${SEPARATE_CODE}" = xyes ; then echo TRUE ; else echo FALSE ; fi`; |
| 49 | link_info.check_relocs_after_open_input = TRUE; |
| 50 | link_info.relro = DEFAULT_LD_Z_RELRO; |
| 51 | } |
| 52 | |
| 53 | static void |
| 54 | aarch64_elf_before_allocation (void) |
| 55 | { |
| 56 | /* We should be able to set the size of the interworking stub section. We |
| 57 | can't do it until later if we have dynamic sections, though. */ |
| 58 | if (! elf_hash_table (&link_info)->dynamic_sections_created) |
| 59 | { |
| 60 | /* Here we rummage through the found bfds to collect information. */ |
| 61 | LANG_FOR_EACH_INPUT_STATEMENT (is) |
| 62 | { |
| 63 | /* Initialise mapping tables for code/data. */ |
| 64 | bfd_elf${ELFSIZE}_aarch64_init_maps (is->the_bfd); |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | /* Call the standard elf routine. */ |
| 69 | gld${EMULATION_NAME}_before_allocation (); |
| 70 | } |
| 71 | |
| 72 | /* Fake input file for stubs. */ |
| 73 | static lang_input_statement_type *stub_file; |
| 74 | |
| 75 | /* Whether we need to call gldarm_layout_sections_again. */ |
| 76 | static int need_laying_out = 0; |
| 77 | |
| 78 | /* Maximum size of a group of input sections that can be handled by |
| 79 | one stub section. A value of +/-1 indicates the bfd back-end |
| 80 | should use a suitable default size. */ |
| 81 | static bfd_signed_vma group_size = 1; |
| 82 | |
| 83 | struct hook_stub_info |
| 84 | { |
| 85 | lang_statement_list_type add; |
| 86 | asection *input_section; |
| 87 | }; |
| 88 | |
| 89 | /* Traverse the linker tree to find the spot where the stub goes. */ |
| 90 | |
| 91 | static bfd_boolean |
| 92 | hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp) |
| 93 | { |
| 94 | lang_statement_union_type *l; |
| 95 | bfd_boolean ret; |
| 96 | |
| 97 | for (; (l = *lp) != NULL; lp = &l->header.next) |
| 98 | { |
| 99 | switch (l->header.type) |
| 100 | { |
| 101 | case lang_constructors_statement_enum: |
| 102 | ret = hook_in_stub (info, &constructor_list.head); |
| 103 | if (ret) |
| 104 | return ret; |
| 105 | break; |
| 106 | |
| 107 | case lang_output_section_statement_enum: |
| 108 | ret = hook_in_stub (info, |
| 109 | &l->output_section_statement.children.head); |
| 110 | if (ret) |
| 111 | return ret; |
| 112 | break; |
| 113 | |
| 114 | case lang_wild_statement_enum: |
| 115 | ret = hook_in_stub (info, &l->wild_statement.children.head); |
| 116 | if (ret) |
| 117 | return ret; |
| 118 | break; |
| 119 | |
| 120 | case lang_group_statement_enum: |
| 121 | ret = hook_in_stub (info, &l->group_statement.children.head); |
| 122 | if (ret) |
| 123 | return ret; |
| 124 | break; |
| 125 | |
| 126 | case lang_input_section_enum: |
| 127 | if (l->input_section.section == info->input_section) |
| 128 | { |
| 129 | /* We've found our section. Insert the stub immediately |
| 130 | after its associated input section. */ |
| 131 | *(info->add.tail) = l->header.next; |
| 132 | l->header.next = info->add.head; |
| 133 | return TRUE; |
| 134 | } |
| 135 | break; |
| 136 | |
| 137 | case lang_data_statement_enum: |
| 138 | case lang_reloc_statement_enum: |
| 139 | case lang_object_symbols_statement_enum: |
| 140 | case lang_output_statement_enum: |
| 141 | case lang_target_statement_enum: |
| 142 | case lang_input_statement_enum: |
| 143 | case lang_assignment_statement_enum: |
| 144 | case lang_padding_statement_enum: |
| 145 | case lang_address_statement_enum: |
| 146 | case lang_fill_statement_enum: |
| 147 | break; |
| 148 | |
| 149 | default: |
| 150 | FAIL (); |
| 151 | break; |
| 152 | } |
| 153 | } |
| 154 | return FALSE; |
| 155 | } |
| 156 | |
| 157 | |
| 158 | /* Call-back for elf${ELFSIZE}_aarch64_size_stubs. */ |
| 159 | |
| 160 | /* Create a new stub section, and arrange for it to be linked |
| 161 | immediately after INPUT_SECTION. */ |
| 162 | |
| 163 | static asection * |
| 164 | elf${ELFSIZE}_aarch64_add_stub_section (const char *stub_sec_name, |
| 165 | asection *input_section) |
| 166 | { |
| 167 | asection *stub_sec; |
| 168 | flagword flags; |
| 169 | asection *output_section; |
| 170 | lang_output_section_statement_type *os; |
| 171 | struct hook_stub_info info; |
| 172 | |
| 173 | flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE |
| 174 | | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP); |
| 175 | stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd, |
| 176 | stub_sec_name, flags); |
| 177 | if (stub_sec == NULL) |
| 178 | goto err_ret; |
| 179 | |
| 180 | /* Long branch stubs contain a 64-bit address, so the section requires |
| 181 | 8 byte alignment. */ |
| 182 | bfd_set_section_alignment (stub_sec, 3); |
| 183 | |
| 184 | output_section = input_section->output_section; |
| 185 | os = lang_output_section_get (output_section); |
| 186 | |
| 187 | info.input_section = input_section; |
| 188 | lang_list_init (&info.add); |
| 189 | lang_add_section (&info.add, stub_sec, NULL, os); |
| 190 | |
| 191 | if (info.add.head == NULL) |
| 192 | goto err_ret; |
| 193 | |
| 194 | if (hook_in_stub (&info, &os->children.head)) |
| 195 | return stub_sec; |
| 196 | |
| 197 | err_ret: |
| 198 | einfo (_("%X%P: can not make stub section: %E\n")); |
| 199 | return NULL; |
| 200 | } |
| 201 | |
| 202 | /* Another call-back for elf${ELFSIZE}_aarch64_size_stubs. */ |
| 203 | |
| 204 | static void |
| 205 | gldaarch64_layout_sections_again (void) |
| 206 | { |
| 207 | /* If we have changed sizes of the stub sections, then we need |
| 208 | to recalculate all the section offsets. This may mean we need to |
| 209 | add even more stubs. */ |
| 210 | ldelf_map_segments (TRUE); |
| 211 | need_laying_out = -1; |
| 212 | } |
| 213 | |
| 214 | static void |
| 215 | build_section_lists (lang_statement_union_type *statement) |
| 216 | { |
| 217 | if (statement->header.type == lang_input_section_enum) |
| 218 | { |
| 219 | asection *i = statement->input_section.section; |
| 220 | |
| 221 | if (!bfd_input_just_syms (i->owner) |
| 222 | && (i->flags & SEC_EXCLUDE) == 0 |
| 223 | && i->output_section != NULL |
| 224 | && i->output_section->owner == link_info.output_bfd) |
| 225 | elf${ELFSIZE}_aarch64_next_input_section (& link_info, i); |
| 226 | } |
| 227 | } |
| 228 | |
| 229 | static void |
| 230 | gld${EMULATION_NAME}_after_allocation (void) |
| 231 | { |
| 232 | int ret; |
| 233 | |
| 234 | /* bfd_elf32_discard_info just plays with debugging sections, |
| 235 | ie. doesn't affect any code, so we can delay resizing the |
| 236 | sections. It's likely we'll resize everything in the process of |
| 237 | adding stubs. */ |
| 238 | ret = bfd_elf_discard_info (link_info.output_bfd, & link_info); |
| 239 | if (ret < 0) |
| 240 | { |
| 241 | einfo (_("%X%P: .eh_frame/.stab edit: %E\n")); |
| 242 | return; |
| 243 | } |
| 244 | else if (ret > 0) |
| 245 | need_laying_out = 1; |
| 246 | |
| 247 | /* If generating a relocatable output file, then we don't |
| 248 | have to examine the relocs. */ |
| 249 | if (stub_file != NULL && !bfd_link_relocatable (&link_info)) |
| 250 | { |
| 251 | ret = elf${ELFSIZE}_aarch64_setup_section_lists (link_info.output_bfd, |
| 252 | &link_info); |
| 253 | if (ret != 0) |
| 254 | { |
| 255 | if (ret < 0) |
| 256 | { |
| 257 | einfo (_("%X%P: could not compute sections lists " |
| 258 | "for stub generation: %E\n")); |
| 259 | return; |
| 260 | } |
| 261 | |
| 262 | lang_for_each_statement (build_section_lists); |
| 263 | |
| 264 | /* Call into the BFD backend to do the real work. */ |
| 265 | if (! elf${ELFSIZE}_aarch64_size_stubs (link_info.output_bfd, |
| 266 | stub_file->the_bfd, |
| 267 | & link_info, |
| 268 | group_size, |
| 269 | & elf${ELFSIZE}_aarch64_add_stub_section, |
| 270 | & gldaarch64_layout_sections_again)) |
| 271 | { |
| 272 | einfo (_("%X%P: can not size stub section: %E\n")); |
| 273 | return; |
| 274 | } |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | if (need_laying_out != -1) |
| 279 | ldelf_map_segments (need_laying_out); |
| 280 | } |
| 281 | |
| 282 | static void |
| 283 | gld${EMULATION_NAME}_finish (void) |
| 284 | { |
| 285 | if (!bfd_link_relocatable (&link_info)) |
| 286 | { |
| 287 | /* Now build the linker stubs. */ |
| 288 | if (stub_file->the_bfd->sections != NULL) |
| 289 | { |
| 290 | if (! elf${ELFSIZE}_aarch64_build_stubs (& link_info)) |
| 291 | einfo (_("%X%P: can not build stubs: %E\n")); |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | finish_default (); |
| 296 | } |
| 297 | |
| 298 | /* This is a convenient point to tell BFD about target specific flags. |
| 299 | After the output has been created, but before inputs are read. */ |
| 300 | static void |
| 301 | aarch64_elf_create_output_section_statements (void) |
| 302 | { |
| 303 | if (strstr (bfd_get_target (link_info.output_bfd), "aarch64") == NULL) |
| 304 | { |
| 305 | /* The arm backend needs special fields in the output hash structure. |
| 306 | These will only be created if the output format is an arm format, |
| 307 | hence we do not support linking and changing output formats at the |
| 308 | same time. Use a link followed by objcopy to change output formats. */ |
| 309 | einfo (_("%F%P: error: cannot change output format " |
| 310 | "whilst linking %s binaries\n"), "AArch64"); |
| 311 | return; |
| 312 | } |
| 313 | |
| 314 | aarch64_bti_pac_info bp_info; |
| 315 | bp_info.plt_type = plt_type; |
| 316 | bp_info.bti_type = bti_type; |
| 317 | |
| 318 | bfd_elf${ELFSIZE}_aarch64_set_options (link_info.output_bfd, &link_info, |
| 319 | no_enum_size_warning, |
| 320 | no_wchar_size_warning, |
| 321 | pic_veneer, |
| 322 | fix_erratum_835769, fix_erratum_843419, |
| 323 | no_apply_dynamic_relocs, |
| 324 | bp_info); |
| 325 | |
| 326 | stub_file = lang_add_input_file ("linker stubs", |
| 327 | lang_input_file_is_fake_enum, |
| 328 | NULL); |
| 329 | stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd); |
| 330 | if (stub_file->the_bfd == NULL |
| 331 | || ! bfd_set_arch_mach (stub_file->the_bfd, |
| 332 | bfd_get_arch (link_info.output_bfd), |
| 333 | bfd_get_mach (link_info.output_bfd))) |
| 334 | { |
| 335 | einfo (_("%F%P: can not create BFD: %E\n")); |
| 336 | return; |
| 337 | } |
| 338 | |
| 339 | stub_file->the_bfd->flags |= BFD_LINKER_CREATED; |
| 340 | ldlang_add_file (stub_file); |
| 341 | } |
| 342 | |
| 343 | EOF |
| 344 | |
| 345 | # Define some shell vars to insert bits of code into the standard elf |
| 346 | # parse_args and list_options functions. |
| 347 | # |
| 348 | PARSE_AND_LIST_PROLOGUE=' |
| 349 | #define OPTION_NO_ENUM_SIZE_WARNING 309 |
| 350 | #define OPTION_PIC_VENEER 310 |
| 351 | #define OPTION_STUBGROUP_SIZE 311 |
| 352 | #define OPTION_NO_WCHAR_SIZE_WARNING 312 |
| 353 | #define OPTION_FIX_ERRATUM_835769 313 |
| 354 | #define OPTION_FIX_ERRATUM_843419 314 |
| 355 | #define OPTION_NO_APPLY_DYNAMIC_RELOCS 315 |
| 356 | ' |
| 357 | |
| 358 | PARSE_AND_LIST_SHORTOPTS=p |
| 359 | |
| 360 | PARSE_AND_LIST_LONGOPTS=' |
| 361 | { "no-pipeline-knowledge", no_argument, NULL, '\'p\''}, |
| 362 | { "no-enum-size-warning", no_argument, NULL, OPTION_NO_ENUM_SIZE_WARNING}, |
| 363 | { "pic-veneer", no_argument, NULL, OPTION_PIC_VENEER}, |
| 364 | { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE }, |
| 365 | { "no-wchar-size-warning", no_argument, NULL, OPTION_NO_WCHAR_SIZE_WARNING}, |
| 366 | { "fix-cortex-a53-835769", no_argument, NULL, OPTION_FIX_ERRATUM_835769}, |
| 367 | { "fix-cortex-a53-843419", optional_argument, NULL, OPTION_FIX_ERRATUM_843419}, |
| 368 | { "no-apply-dynamic-relocs", no_argument, NULL, OPTION_NO_APPLY_DYNAMIC_RELOCS}, |
| 369 | ' |
| 370 | |
| 371 | PARSE_AND_LIST_OPTIONS=' |
| 372 | fprintf (file, _(" --no-enum-size-warning Don'\''t warn about objects with incompatible\n" |
| 373 | " enum sizes\n")); |
| 374 | fprintf (file, _(" --no-wchar-size-warning Don'\''t warn about objects with incompatible\n" |
| 375 | " wchar_t sizes\n")); |
| 376 | fprintf (file, _(" --pic-veneer Always generate PIC interworking veneers\n")); |
| 377 | fprintf (file, _("\ |
| 378 | --stub-group-size=N Maximum size of a group of input sections that\n\ |
| 379 | can be handled by one stub section. A negative\n\ |
| 380 | value locates all stubs after their branches\n\ |
| 381 | (with a group size of -N), while a positive\n\ |
| 382 | value allows two groups of input sections, one\n\ |
| 383 | before, and one after each stub section.\n\ |
| 384 | Values of +/-1 indicate the linker should\n\ |
| 385 | choose suitable defaults.\n")); |
| 386 | fprintf (file, _(" --fix-cortex-a53-835769 Fix erratum 835769\n")); |
| 387 | fprintf (file, _("\ |
| 388 | --fix-cortex-a53-843419[=full|adr|adrp] Fix erratum 843419 and optionally specify which workaround to use.\n\ |
| 389 | full (default): Use both ADRP and ADR workaround, this will \n\ |
| 390 | increase the size of your binaries.\n\ |
| 391 | adr: Only use the ADR workaround, this will not cause any increase\n\ |
| 392 | in binary size but linking will fail if the referenced address is\n\ |
| 393 | out of range of an ADR instruction. This will remove the need of using\n\ |
| 394 | a veneer and results in both performance and size benefits.\n\ |
| 395 | adrp: Use only the ADRP workaround, this will never rewrite your ADRP\n\ |
| 396 | instruction into an ADR. As such the workaround will always use a\n\ |
| 397 | veneer and this will give you both a performance and size overhead.\n")); |
| 398 | fprintf (file, _(" --no-apply-dynamic-relocs Do not apply link-time values for dynamic relocations\n")); |
| 399 | fprintf (file, _(" -z force-bti Turn on Branch Target Identification mechanism and generate PLTs with BTI. Generate warnings for missing BTI on inputs\n")); |
| 400 | fprintf (file, _(" -z pac-plt Protect PLTs with Pointer Authentication.\n")); |
| 401 | ' |
| 402 | |
| 403 | PARSE_AND_LIST_ARGS_CASE_Z_AARCH64=' |
| 404 | else if (strcmp (optarg, "force-bti") == 0) |
| 405 | { |
| 406 | plt_type |= PLT_BTI; |
| 407 | bti_type = BTI_WARN; |
| 408 | } |
| 409 | else if (strcmp (optarg, "pac-plt") == 0) |
| 410 | plt_type |= PLT_PAC; |
| 411 | ' |
| 412 | PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_AARCH64" |
| 413 | |
| 414 | PARSE_AND_LIST_ARGS_CASES=' |
| 415 | case '\'p\'': |
| 416 | /* Only here for backwards compatibility. */ |
| 417 | break; |
| 418 | |
| 419 | case OPTION_NO_ENUM_SIZE_WARNING: |
| 420 | no_enum_size_warning = 1; |
| 421 | break; |
| 422 | |
| 423 | case OPTION_NO_WCHAR_SIZE_WARNING: |
| 424 | no_wchar_size_warning = 1; |
| 425 | break; |
| 426 | |
| 427 | case OPTION_PIC_VENEER: |
| 428 | pic_veneer = 1; |
| 429 | break; |
| 430 | |
| 431 | case OPTION_FIX_ERRATUM_835769: |
| 432 | fix_erratum_835769 = 1; |
| 433 | break; |
| 434 | |
| 435 | case OPTION_FIX_ERRATUM_843419: |
| 436 | fix_erratum_843419 = ERRAT_ADR | ERRAT_ADRP; |
| 437 | if (optarg && *optarg) |
| 438 | { |
| 439 | if (strcmp ("full", optarg) == 0) |
| 440 | fix_erratum_843419 = ERRAT_ADR | ERRAT_ADRP; |
| 441 | else if (strcmp ("adrp", optarg) == 0) |
| 442 | fix_erratum_843419 = ERRAT_ADRP; |
| 443 | else if (strcmp ("adr", optarg) == 0) |
| 444 | fix_erratum_843419 = ERRAT_ADR; |
| 445 | else |
| 446 | einfo (_("%P: error: unrecognized option for " |
| 447 | "--fix-cortex-a53-843419: %s\n"), optarg); |
| 448 | } |
| 449 | break; |
| 450 | |
| 451 | case OPTION_NO_APPLY_DYNAMIC_RELOCS: |
| 452 | no_apply_dynamic_relocs = 1; |
| 453 | break; |
| 454 | |
| 455 | case OPTION_STUBGROUP_SIZE: |
| 456 | { |
| 457 | const char *end; |
| 458 | |
| 459 | group_size = bfd_scan_vma (optarg, &end, 0); |
| 460 | if (*end) |
| 461 | einfo (_("%F%P: invalid number `%s'\''\n"), optarg); |
| 462 | } |
| 463 | break; |
| 464 | ' |
| 465 | |
| 466 | # We have our own before_allocation etc. functions, but they call |
| 467 | # the standard routines, so give them a different name. |
| 468 | LDEMUL_BEFORE_ALLOCATION=aarch64_elf_before_allocation |
| 469 | LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation |
| 470 | LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=aarch64_elf_create_output_section_statements |
| 471 | |
| 472 | # Replace the elf before_parse function with our own. |
| 473 | LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse |
| 474 | |
| 475 | # Call the extra arm-elf function |
| 476 | LDEMUL_FINISH=gld${EMULATION_NAME}_finish |