1 # This shell script emits a C file. -*- C -*-
2 # Copyright (C) 2009-2021 Free Software Foundation, Inc.
3 # Contributed by ARM Ltd.
5 # This file is part of the GNU Binutils.
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.
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.
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/>.
22 # This file is sourced from elf.em, and defines extra aarch64-elf
28 #include "elf/aarch64.h"
29 #include "elfxx-aarch64.h"
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;
41 gld${EMULATION_NAME}_before_parse (void)
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${SEPARATE_CODE}" = xyes ; then echo TRUE ; else echo FALSE ; fi`;
49 link_info.check_relocs_after_open_input = TRUE;
51 if test -n "$COMMONPAGESIZE"; then
53 link_info.relro = DEFAULT_LD_Z_RELRO;
60 aarch64_elf_before_allocation (void)
62 /* We should be able to set the size of the interworking stub section. We
63 can't do it until later if we have dynamic sections, though. */
64 if (! elf_hash_table (&link_info)->dynamic_sections_created)
66 /* Here we rummage through the found bfds to collect information. */
67 LANG_FOR_EACH_INPUT_STATEMENT (is)
69 /* Initialise mapping tables for code/data. */
70 bfd_elf${ELFSIZE}_aarch64_init_maps (is->the_bfd);
74 /* Call the standard elf routine. */
75 gld${EMULATION_NAME}_before_allocation ();
78 /* Fake input file for stubs. */
79 static lang_input_statement_type *stub_file;
81 /* Whether we need to call gldarm_layout_sections_again. */
82 static int need_laying_out = 0;
84 /* Maximum size of a group of input sections that can be handled by
85 one stub section. A value of +/-1 indicates the bfd back-end
86 should use a suitable default size. */
87 static bfd_signed_vma group_size = 1;
91 lang_statement_list_type add;
92 asection *input_section;
95 /* Traverse the linker tree to find the spot where the stub goes. */
98 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
100 lang_statement_union_type *l;
103 for (; (l = *lp) != NULL; lp = &l->header.next)
105 switch (l->header.type)
107 case lang_constructors_statement_enum:
108 ret = hook_in_stub (info, &constructor_list.head);
113 case lang_output_section_statement_enum:
114 ret = hook_in_stub (info,
115 &l->output_section_statement.children.head);
120 case lang_wild_statement_enum:
121 ret = hook_in_stub (info, &l->wild_statement.children.head);
126 case lang_group_statement_enum:
127 ret = hook_in_stub (info, &l->group_statement.children.head);
132 case lang_input_section_enum:
133 if (l->input_section.section == info->input_section)
135 /* We've found our section. Insert the stub immediately
136 after its associated input section. */
137 *(info->add.tail) = l->header.next;
138 l->header.next = info->add.head;
143 case lang_data_statement_enum:
144 case lang_reloc_statement_enum:
145 case lang_object_symbols_statement_enum:
146 case lang_output_statement_enum:
147 case lang_target_statement_enum:
148 case lang_input_statement_enum:
149 case lang_assignment_statement_enum:
150 case lang_padding_statement_enum:
151 case lang_address_statement_enum:
152 case lang_fill_statement_enum:
164 /* Call-back for elf${ELFSIZE}_aarch64_size_stubs. */
166 /* Create a new stub section, and arrange for it to be linked
167 immediately after INPUT_SECTION. */
170 elf${ELFSIZE}_aarch64_add_stub_section (const char *stub_sec_name,
171 asection *input_section)
175 asection *output_section;
176 lang_output_section_statement_type *os;
177 struct hook_stub_info info;
179 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
180 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
181 stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
182 stub_sec_name, flags);
183 if (stub_sec == NULL)
186 /* Long branch stubs contain a 64-bit address, so the section requires
188 bfd_set_section_alignment (stub_sec, 3);
190 output_section = input_section->output_section;
191 os = lang_output_section_get (output_section);
193 info.input_section = input_section;
194 lang_list_init (&info.add);
195 lang_add_section (&info.add, stub_sec, NULL, os);
197 if (info.add.head == NULL)
200 if (hook_in_stub (&info, &os->children.head))
204 einfo (_("%X%P: can not make stub section: %E\n"));
208 /* Another call-back for elf${ELFSIZE}_aarch64_size_stubs. */
211 gldaarch64_layout_sections_again (void)
213 /* If we have changed sizes of the stub sections, then we need
214 to recalculate all the section offsets. This may mean we need to
215 add even more stubs. */
216 ldelf_map_segments (TRUE);
217 need_laying_out = -1;
221 build_section_lists (lang_statement_union_type *statement)
223 if (statement->header.type == lang_input_section_enum)
225 asection *i = statement->input_section.section;
227 if (!bfd_input_just_syms (i->owner)
228 && (i->flags & SEC_EXCLUDE) == 0
229 && i->output_section != NULL
230 && i->output_section->owner == link_info.output_bfd)
231 elf${ELFSIZE}_aarch64_next_input_section (& link_info, i);
236 gld${EMULATION_NAME}_after_allocation (void)
240 /* bfd_elf32_discard_info just plays with debugging sections,
241 ie. doesn't affect any code, so we can delay resizing the
242 sections. It's likely we'll resize everything in the process of
244 ret = bfd_elf_discard_info (link_info.output_bfd, & link_info);
247 einfo (_("%X%P: .eh_frame/.stab edit: %E\n"));
253 /* If generating a relocatable output file, then we don't
254 have to examine the relocs. */
255 if (stub_file != NULL && !bfd_link_relocatable (&link_info))
257 ret = elf${ELFSIZE}_aarch64_setup_section_lists (link_info.output_bfd,
263 einfo (_("%X%P: could not compute sections lists "
264 "for stub generation: %E\n"));
268 lang_for_each_statement (build_section_lists);
270 /* Call into the BFD backend to do the real work. */
271 if (! elf${ELFSIZE}_aarch64_size_stubs (link_info.output_bfd,
275 & elf${ELFSIZE}_aarch64_add_stub_section,
276 & gldaarch64_layout_sections_again))
278 einfo (_("%X%P: can not size stub section: %E\n"));
284 if (need_laying_out != -1)
285 ldelf_map_segments (need_laying_out);
289 gld${EMULATION_NAME}_finish (void)
291 if (!bfd_link_relocatable (&link_info))
293 /* Now build the linker stubs. */
294 if (stub_file->the_bfd->sections != NULL)
296 if (! elf${ELFSIZE}_aarch64_build_stubs (& link_info))
297 einfo (_("%X%P: can not build stubs: %E\n"));
304 /* This is a convenient point to tell BFD about target specific flags.
305 After the output has been created, but before inputs are read. */
307 aarch64_elf_create_output_section_statements (void)
309 if (strstr (bfd_get_target (link_info.output_bfd), "aarch64") == NULL)
311 /* The arm backend needs special fields in the output hash structure.
312 These will only be created if the output format is an arm format,
313 hence we do not support linking and changing output formats at the
314 same time. Use a link followed by objcopy to change output formats. */
315 einfo (_("%F%P: error: cannot change output format "
316 "whilst linking %s binaries\n"), "AArch64");
320 aarch64_bti_pac_info bp_info;
321 bp_info.plt_type = plt_type;
322 bp_info.bti_type = bti_type;
324 bfd_elf${ELFSIZE}_aarch64_set_options (link_info.output_bfd, &link_info,
325 no_enum_size_warning,
326 no_wchar_size_warning,
328 fix_erratum_835769, fix_erratum_843419,
329 no_apply_dynamic_relocs,
332 stub_file = lang_add_input_file ("linker stubs",
333 lang_input_file_is_fake_enum,
335 stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
336 if (stub_file->the_bfd == NULL
337 || ! bfd_set_arch_mach (stub_file->the_bfd,
338 bfd_get_arch (link_info.output_bfd),
339 bfd_get_mach (link_info.output_bfd)))
341 einfo (_("%F%P: can not create BFD: %E\n"));
345 stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
346 ldlang_add_file (stub_file);
351 # Define some shell vars to insert bits of code into the standard elf
352 # parse_args and list_options functions.
354 PARSE_AND_LIST_PROLOGUE='
355 #define OPTION_NO_ENUM_SIZE_WARNING 309
356 #define OPTION_PIC_VENEER 310
357 #define OPTION_STUBGROUP_SIZE 311
358 #define OPTION_NO_WCHAR_SIZE_WARNING 312
359 #define OPTION_FIX_ERRATUM_835769 313
360 #define OPTION_FIX_ERRATUM_843419 314
361 #define OPTION_NO_APPLY_DYNAMIC_RELOCS 315
364 PARSE_AND_LIST_SHORTOPTS=p
366 PARSE_AND_LIST_LONGOPTS='
367 { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
368 { "no-enum-size-warning", no_argument, NULL, OPTION_NO_ENUM_SIZE_WARNING},
369 { "pic-veneer", no_argument, NULL, OPTION_PIC_VENEER},
370 { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
371 { "no-wchar-size-warning", no_argument, NULL, OPTION_NO_WCHAR_SIZE_WARNING},
372 { "fix-cortex-a53-835769", no_argument, NULL, OPTION_FIX_ERRATUM_835769},
373 { "fix-cortex-a53-843419", optional_argument, NULL, OPTION_FIX_ERRATUM_843419},
374 { "no-apply-dynamic-relocs", no_argument, NULL, OPTION_NO_APPLY_DYNAMIC_RELOCS},
377 PARSE_AND_LIST_OPTIONS='
378 fprintf (file, _(" --no-enum-size-warning Don'\''t warn about objects with incompatible\n"
380 fprintf (file, _(" --no-wchar-size-warning Don'\''t warn about objects with incompatible\n"
381 " wchar_t sizes\n"));
382 fprintf (file, _(" --pic-veneer Always generate PIC interworking veneers\n"));
384 --stub-group-size=N Maximum size of a group of input sections that\n\
385 can be handled by one stub section. A negative\n\
386 value locates all stubs after their branches\n\
387 (with a group size of -N), while a positive\n\
388 value allows two groups of input sections, one\n\
389 before, and one after each stub section.\n\
390 Values of +/-1 indicate the linker should\n\
391 choose suitable defaults.\n"));
392 fprintf (file, _(" --fix-cortex-a53-835769 Fix erratum 835769\n"));
394 --fix-cortex-a53-843419[=full|adr|adrp] Fix erratum 843419 and optionally specify which workaround to use.\n\
395 full (default): Use both ADRP and ADR workaround, this will \n\
396 increase the size of your binaries.\n\
397 adr: Only use the ADR workaround, this will not cause any increase\n\
398 in binary size but linking will fail if the referenced address is\n\
399 out of range of an ADR instruction. This will remove the need of using\n\
400 a veneer and results in both performance and size benefits.\n\
401 adrp: Use only the ADRP workaround, this will never rewrite your ADRP\n\
402 instruction into an ADR. As such the workaround will always use a\n\
403 veneer and this will give you both a performance and size overhead.\n"));
404 fprintf (file, _(" --no-apply-dynamic-relocs Do not apply link-time values for dynamic relocations\n"));
405 fprintf (file, _(" -z force-bti Turn on Branch Target Identification mechanism and generate PLTs with BTI. Generate warnings for missing BTI on inputs\n"));
406 fprintf (file, _(" -z pac-plt Protect PLTs with Pointer Authentication.\n"));
409 PARSE_AND_LIST_ARGS_CASE_Z_AARCH64='
410 else if (strcmp (optarg, "force-bti") == 0)
415 else if (strcmp (optarg, "pac-plt") == 0)
418 PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_AARCH64"
420 PARSE_AND_LIST_ARGS_CASES='
422 /* Only here for backwards compatibility. */
425 case OPTION_NO_ENUM_SIZE_WARNING:
426 no_enum_size_warning = 1;
429 case OPTION_NO_WCHAR_SIZE_WARNING:
430 no_wchar_size_warning = 1;
433 case OPTION_PIC_VENEER:
437 case OPTION_FIX_ERRATUM_835769:
438 fix_erratum_835769 = 1;
441 case OPTION_FIX_ERRATUM_843419:
442 fix_erratum_843419 = ERRAT_ADR | ERRAT_ADRP;
443 if (optarg && *optarg)
445 if (strcmp ("full", optarg) == 0)
446 fix_erratum_843419 = ERRAT_ADR | ERRAT_ADRP;
447 else if (strcmp ("adrp", optarg) == 0)
448 fix_erratum_843419 = ERRAT_ADRP;
449 else if (strcmp ("adr", optarg) == 0)
450 fix_erratum_843419 = ERRAT_ADR;
452 einfo (_("%P: error: unrecognized option for "
453 "--fix-cortex-a53-843419: %s\n"), optarg);
457 case OPTION_NO_APPLY_DYNAMIC_RELOCS:
458 no_apply_dynamic_relocs = 1;
461 case OPTION_STUBGROUP_SIZE:
465 group_size = bfd_scan_vma (optarg, &end, 0);
467 einfo (_("%F%P: invalid number `%s'\''\n"), optarg);
472 # We have our own before_allocation etc. functions, but they call
473 # the standard routines, so give them a different name.
474 LDEMUL_BEFORE_ALLOCATION=aarch64_elf_before_allocation
475 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
476 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=aarch64_elf_create_output_section_statements
478 # Replace the elf before_parse function with our own.
479 LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse
481 # Call the extra arm-elf function
482 LDEMUL_FINISH=gld${EMULATION_NAME}_finish