1 # This shell script emits a C file. -*- C -*-
2 # Copyright (C) 2009-2022 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;
57 link_info.separate_code = DEFAULT_LD_Z_SEPARATE_CODE;
58 link_info.warn_execstack = DEFAULT_LD_WARN_EXECSTACK;
59 link_info.no_warn_rwx_segments = ! DEFAULT_LD_WARN_RWX_SEGMENTS;
60 link_info.default_execstack = DEFAULT_LD_EXECSTACK;
64 aarch64_elf_before_allocation (void)
66 /* We should be able to set the size of the interworking stub section. We
67 can't do it until later if we have dynamic sections, though. */
68 if (! elf_hash_table (&link_info)->dynamic_sections_created)
70 /* Here we rummage through the found bfds to collect information. */
71 LANG_FOR_EACH_INPUT_STATEMENT (is)
73 /* Initialise mapping tables for code/data. */
74 bfd_elf${ELFSIZE}_aarch64_init_maps (is->the_bfd);
78 /* Call the standard elf routine. */
79 gld${EMULATION_NAME}_before_allocation ();
82 /* Fake input file for stubs. */
83 static lang_input_statement_type *stub_file;
85 /* Whether we need to call gldarm_layout_sections_again. */
86 static int need_laying_out = 0;
88 /* Maximum size of a group of input sections that can be handled by
89 one stub section. A value of +/-1 indicates the bfd back-end
90 should use a suitable default size. */
91 static bfd_signed_vma group_size = 1;
95 lang_statement_list_type add;
96 asection *input_section;
99 /* Traverse the linker tree to find the spot where the stub goes. */
102 hook_in_stub (struct hook_stub_info *info, lang_statement_union_type **lp)
104 lang_statement_union_type *l;
107 for (; (l = *lp) != NULL; lp = &l->header.next)
109 switch (l->header.type)
111 case lang_constructors_statement_enum:
112 ret = hook_in_stub (info, &constructor_list.head);
117 case lang_output_section_statement_enum:
118 ret = hook_in_stub (info,
119 &l->output_section_statement.children.head);
124 case lang_wild_statement_enum:
125 ret = hook_in_stub (info, &l->wild_statement.children.head);
130 case lang_group_statement_enum:
131 ret = hook_in_stub (info, &l->group_statement.children.head);
136 case lang_input_section_enum:
137 if (l->input_section.section == info->input_section)
139 /* We've found our section. Insert the stub immediately
140 after its associated input section. */
141 *(info->add.tail) = l->header.next;
142 l->header.next = info->add.head;
147 case lang_data_statement_enum:
148 case lang_reloc_statement_enum:
149 case lang_object_symbols_statement_enum:
150 case lang_output_statement_enum:
151 case lang_target_statement_enum:
152 case lang_input_statement_enum:
153 case lang_assignment_statement_enum:
154 case lang_padding_statement_enum:
155 case lang_address_statement_enum:
156 case lang_fill_statement_enum:
168 /* Call-back for elf${ELFSIZE}_aarch64_size_stubs. */
170 /* Create a new stub section, and arrange for it to be linked
171 immediately after INPUT_SECTION. */
174 elf${ELFSIZE}_aarch64_add_stub_section (const char *stub_sec_name,
175 asection *input_section)
179 asection *output_section;
180 lang_output_section_statement_type *os;
181 struct hook_stub_info info;
183 flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE
184 | SEC_HAS_CONTENTS | SEC_RELOC | SEC_IN_MEMORY | SEC_KEEP);
185 stub_sec = bfd_make_section_anyway_with_flags (stub_file->the_bfd,
186 stub_sec_name, flags);
187 if (stub_sec == NULL)
190 /* Long branch stubs contain a 64-bit address, so the section requires
192 bfd_set_section_alignment (stub_sec, 3);
194 output_section = input_section->output_section;
195 os = lang_output_section_get (output_section);
197 info.input_section = input_section;
198 lang_list_init (&info.add);
199 lang_add_section (&info.add, stub_sec, NULL, NULL, os);
201 if (info.add.head == NULL)
204 if (hook_in_stub (&info, &os->children.head))
208 einfo (_("%X%P: can not make stub section: %E\n"));
212 /* Another call-back for elf${ELFSIZE}_aarch64_size_stubs. */
215 gldaarch64_layout_sections_again (void)
217 /* If we have changed sizes of the stub sections, then we need
218 to recalculate all the section offsets. This may mean we need to
219 add even more stubs. */
220 ldelf_map_segments (true);
221 need_laying_out = -1;
225 build_section_lists (lang_statement_union_type *statement)
227 if (statement->header.type == lang_input_section_enum)
229 asection *i = statement->input_section.section;
231 if (!bfd_input_just_syms (i->owner)
232 && (i->flags & SEC_EXCLUDE) == 0
233 && i->output_section != NULL
234 && i->output_section->owner == link_info.output_bfd)
235 elf${ELFSIZE}_aarch64_next_input_section (& link_info, i);
240 gld${EMULATION_NAME}_after_allocation (void)
244 /* bfd_elf32_discard_info just plays with debugging sections,
245 ie. doesn't affect any code, so we can delay resizing the
246 sections. It's likely we'll resize everything in the process of
248 ret = bfd_elf_discard_info (link_info.output_bfd, & link_info);
251 einfo (_("%X%P: .eh_frame/.stab edit: %E\n"));
257 /* If generating a relocatable output file, then we don't
258 have to examine the relocs. */
259 if (stub_file != NULL && !bfd_link_relocatable (&link_info))
261 ret = elf${ELFSIZE}_aarch64_setup_section_lists (link_info.output_bfd,
267 einfo (_("%X%P: could not compute sections lists "
268 "for stub generation: %E\n"));
272 lang_for_each_statement (build_section_lists);
274 /* Call into the BFD backend to do the real work. */
275 if (! elf${ELFSIZE}_aarch64_size_stubs (link_info.output_bfd,
279 & elf${ELFSIZE}_aarch64_add_stub_section,
280 & gldaarch64_layout_sections_again))
282 einfo (_("%X%P: can not size stub section: %E\n"));
288 if (need_laying_out != -1)
289 ldelf_map_segments (need_laying_out);
293 gld${EMULATION_NAME}_finish (void)
295 if (!bfd_link_relocatable (&link_info))
297 /* Now build the linker stubs. */
298 if (stub_file->the_bfd->sections != NULL)
300 if (! elf${ELFSIZE}_aarch64_build_stubs (& link_info))
301 einfo (_("%X%P: can not build stubs: %E\n"));
308 /* This is a convenient point to tell BFD about target specific flags.
309 After the output has been created, but before inputs are read. */
311 aarch64_elf_create_output_section_statements (void)
313 if (strstr (bfd_get_target (link_info.output_bfd), "aarch64") == NULL)
315 /* The arm backend needs special fields in the output hash structure.
316 These will only be created if the output format is an arm format,
317 hence we do not support linking and changing output formats at the
318 same time. Use a link followed by objcopy to change output formats. */
319 einfo (_("%F%P: error: cannot change output format "
320 "whilst linking %s binaries\n"), "AArch64");
324 aarch64_bti_pac_info bp_info;
325 bp_info.plt_type = plt_type;
326 bp_info.bti_type = bti_type;
328 bfd_elf${ELFSIZE}_aarch64_set_options (link_info.output_bfd, &link_info,
329 no_enum_size_warning,
330 no_wchar_size_warning,
332 fix_erratum_835769, fix_erratum_843419,
333 no_apply_dynamic_relocs,
336 stub_file = lang_add_input_file ("linker stubs",
337 lang_input_file_is_fake_enum,
339 stub_file->the_bfd = bfd_create ("linker stubs", link_info.output_bfd);
340 if (stub_file->the_bfd == NULL
341 || ! bfd_set_arch_mach (stub_file->the_bfd,
342 bfd_get_arch (link_info.output_bfd),
343 bfd_get_mach (link_info.output_bfd)))
345 einfo (_("%F%P: can not create BFD: %E\n"));
349 stub_file->the_bfd->flags |= BFD_LINKER_CREATED;
350 ldlang_add_file (stub_file);
355 # Define some shell vars to insert bits of code into the standard elf
356 # parse_args and list_options functions.
358 PARSE_AND_LIST_PROLOGUE='
359 #define OPTION_NO_ENUM_SIZE_WARNING 309
360 #define OPTION_PIC_VENEER 310
361 #define OPTION_STUBGROUP_SIZE 311
362 #define OPTION_NO_WCHAR_SIZE_WARNING 312
363 #define OPTION_FIX_ERRATUM_835769 313
364 #define OPTION_FIX_ERRATUM_843419 314
365 #define OPTION_NO_APPLY_DYNAMIC_RELOCS 315
368 PARSE_AND_LIST_SHORTOPTS=p
370 PARSE_AND_LIST_LONGOPTS='
371 { "no-pipeline-knowledge", no_argument, NULL, '\'p\''},
372 { "no-enum-size-warning", no_argument, NULL, OPTION_NO_ENUM_SIZE_WARNING},
373 { "pic-veneer", no_argument, NULL, OPTION_PIC_VENEER},
374 { "stub-group-size", required_argument, NULL, OPTION_STUBGROUP_SIZE },
375 { "no-wchar-size-warning", no_argument, NULL, OPTION_NO_WCHAR_SIZE_WARNING},
376 { "fix-cortex-a53-835769", no_argument, NULL, OPTION_FIX_ERRATUM_835769},
377 { "fix-cortex-a53-843419", optional_argument, NULL, OPTION_FIX_ERRATUM_843419},
378 { "no-apply-dynamic-relocs", no_argument, NULL, OPTION_NO_APPLY_DYNAMIC_RELOCS},
381 PARSE_AND_LIST_OPTIONS='
382 fprintf (file, _(" --no-enum-size-warning Don'\''t warn about objects with incompatible\n"
384 fprintf (file, _(" --no-wchar-size-warning Don'\''t warn about objects with incompatible\n"
385 " wchar_t sizes\n"));
386 fprintf (file, _(" --pic-veneer Always generate PIC interworking veneers\n"));
388 --stub-group-size=N Maximum size of a group of input sections that\n\
389 can be handled by one stub section. A negative\n\
390 value locates all stubs after their branches\n\
391 (with a group size of -N), while a positive\n\
392 value allows two groups of input sections, one\n\
393 before, and one after each stub section.\n\
394 Values of +/-1 indicate the linker should\n\
395 choose suitable defaults.\n"));
396 fprintf (file, _(" --fix-cortex-a53-835769 Fix erratum 835769\n"));
398 --fix-cortex-a53-843419[=full|adr|adrp] Fix erratum 843419 and optionally specify which workaround to use.\n\
399 full (default): Use both ADRP and ADR workaround, this will \n\
400 increase the size of your binaries.\n\
401 adr: Only use the ADR workaround, this will not cause any increase\n\
402 in binary size but linking will fail if the referenced address is\n\
403 out of range of an ADR instruction. This will remove the need of using\n\
404 a veneer and results in both performance and size benefits.\n\
405 adrp: Use only the ADRP workaround, this will never rewrite your ADRP\n\
406 instruction into an ADR. As such the workaround will always use a\n\
407 veneer and this will give you both a performance and size overhead.\n"));
408 fprintf (file, _(" --no-apply-dynamic-relocs Do not apply link-time values for dynamic relocations\n"));
409 fprintf (file, _(" -z force-bti Turn on Branch Target Identification mechanism and generate PLTs with BTI. Generate warnings for missing BTI on inputs\n"));
410 fprintf (file, _(" -z pac-plt Protect PLTs with Pointer Authentication.\n"));
413 PARSE_AND_LIST_ARGS_CASE_Z_AARCH64='
414 else if (strcmp (optarg, "force-bti") == 0)
419 else if (strcmp (optarg, "pac-plt") == 0)
422 PARSE_AND_LIST_ARGS_CASE_Z="$PARSE_AND_LIST_ARGS_CASE_Z $PARSE_AND_LIST_ARGS_CASE_Z_AARCH64"
424 PARSE_AND_LIST_ARGS_CASES='
426 /* Only here for backwards compatibility. */
429 case OPTION_NO_ENUM_SIZE_WARNING:
430 no_enum_size_warning = 1;
433 case OPTION_NO_WCHAR_SIZE_WARNING:
434 no_wchar_size_warning = 1;
437 case OPTION_PIC_VENEER:
441 case OPTION_FIX_ERRATUM_835769:
442 fix_erratum_835769 = 1;
445 case OPTION_FIX_ERRATUM_843419:
446 fix_erratum_843419 = ERRAT_ADR | ERRAT_ADRP;
447 if (optarg && *optarg)
449 if (strcmp ("full", optarg) == 0)
450 fix_erratum_843419 = ERRAT_ADR | ERRAT_ADRP;
451 else if (strcmp ("adrp", optarg) == 0)
452 fix_erratum_843419 = ERRAT_ADRP;
453 else if (strcmp ("adr", optarg) == 0)
454 fix_erratum_843419 = ERRAT_ADR;
456 einfo (_("%P: error: unrecognized option for "
457 "--fix-cortex-a53-843419: %s\n"), optarg);
461 case OPTION_NO_APPLY_DYNAMIC_RELOCS:
462 no_apply_dynamic_relocs = 1;
465 case OPTION_STUBGROUP_SIZE:
469 group_size = bfd_scan_vma (optarg, &end, 0);
471 einfo (_("%F%P: invalid number `%s'\''\n"), optarg);
476 # We have our own before_allocation etc. functions, but they call
477 # the standard routines, so give them a different name.
478 LDEMUL_BEFORE_ALLOCATION=aarch64_elf_before_allocation
479 LDEMUL_AFTER_ALLOCATION=gld${EMULATION_NAME}_after_allocation
480 LDEMUL_CREATE_OUTPUT_SECTION_STATEMENTS=aarch64_elf_create_output_section_statements
482 # Replace the elf before_parse function with our own.
483 LDEMUL_BEFORE_PARSE=gld"${EMULATION_NAME}"_before_parse
485 # Call the extra arm-elf function
486 LDEMUL_FINISH=gld${EMULATION_NAME}_finish