1/*
2 * Helper macros to support writing architecture specific
3 * linker scripts.
4 *
5 * A minimal linker scripts has following content:
6 * [This is a sample, architectures may have special requiriements]
7 *
8 * OUTPUT_FORMAT(...)
9 * OUTPUT_ARCH(...)
10 * ENTRY(...)
11 * SECTIONS
12 * {
13 * . = START;
14 * __init_begin = .;
15 * HEAD_TEXT_SECTION
16 * INIT_TEXT_SECTION(PAGE_SIZE)
17 * INIT_DATA_SECTION(...)
18 * PERCPU_SECTION(CACHELINE_SIZE)
19 * __init_end = .;
20 *
21 * _stext = .;
22 * TEXT_SECTION = 0
23 * _etext = .;
24 *
25 * _sdata = .;
26 * RO_DATA(PAGE_SIZE)
27 * RW_DATA(...)
28 * _edata = .;
29 *
30 * EXCEPTION_TABLE(...)
31 *
32 * BSS_SECTION(0, 0, 0)
33 * _end = .;
34 *
35 * STABS_DEBUG
36 * DWARF_DEBUG
37 * ELF_DETAILS
38 *
39 * DISCARDS // must be the last
40 * }
41 *
42 * [__init_begin, __init_end] is the init section that may be freed after init
43 * // __init_begin and __init_end should be page aligned, so that we can
44 * // free the whole .init memory
45 * [_stext, _etext] is the text section
46 * [_sdata, _edata] is the data section
47 *
48 * Some of the included output section have their own set of constants.
49 * Examples are: [__initramfs_start, __initramfs_end] for initramfs and
50 * [__nosave_begin, __nosave_end] for the nosave data
51 */
52
53#ifndef LOAD_OFFSET
54#define LOAD_OFFSET 0
55#endif
56
57/*
58 * Only some architectures want to have the .notes segment visible in
59 * a separate PT_NOTE ELF Program Header. When this happens, it needs
60 * to be visible in both the kernel text's PT_LOAD and the PT_NOTE
61 * Program Headers. In this case, though, the PT_LOAD needs to be made
62 * the default again so that all the following sections don't also end
63 * up in the PT_NOTE Program Header.
64 */
65#ifdef EMITS_PT_NOTE
66#define NOTES_HEADERS :text :note
67#define NOTES_HEADERS_RESTORE __restore_ph : { *(.__restore_ph) } :text
68#else
69#define NOTES_HEADERS
70#define NOTES_HEADERS_RESTORE
71#endif
72
73/*
74 * Some architectures have non-executable read-only exception tables.
75 * They can be added to the RO_DATA segment by specifying their desired
76 * alignment.
77 */
78#ifdef RO_EXCEPTION_TABLE_ALIGN
79#define RO_EXCEPTION_TABLE EXCEPTION_TABLE(RO_EXCEPTION_TABLE_ALIGN)
80#else
81#define RO_EXCEPTION_TABLE
82#endif
83
84/* Align . function alignment. */
85#define ALIGN_FUNCTION() . = ALIGN(CONFIG_FUNCTION_ALIGNMENT)
86
87/*
88 * LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which
89 * generates .data.identifier sections, which need to be pulled in with
90 * .data. We don't want to pull in .data..other sections, which Linux
91 * has defined. Same for text and bss.
92 *
93 * With LTO_CLANG, the linker also splits sections by default, so we need
94 * these macros to combine the sections during the final link.
95 *
96 * RODATA_MAIN is not used because existing code already defines .rodata.x
97 * sections to be brought in with rodata.
98 */
99#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG)
100#define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
101#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$L*
102#define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]*
103#define RODATA_MAIN .rodata .rodata.[0-9a-zA-Z_]* .rodata..L*
104#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]* .bss..compoundliteral*
105#define SBSS_MAIN .sbss .sbss.[0-9a-zA-Z_]*
106#else
107#define TEXT_MAIN .text
108#define DATA_MAIN .data
109#define SDATA_MAIN .sdata
110#define RODATA_MAIN .rodata
111#define BSS_MAIN .bss
112#define SBSS_MAIN .sbss
113#endif
114
115/*
116 * GCC 4.5 and later have a 32 bytes section alignment for structures.
117 * Except GCC 4.9, that feels the need to align on 64 bytes.
118 */
119#define STRUCT_ALIGNMENT 32
120#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
121
122/*
123 * The order of the sched class addresses are important, as they are
124 * used to determine the order of the priority of each sched class in
125 * relation to each other.
126 */
127#define SCHED_DATA \
128 STRUCT_ALIGN(); \
129 __sched_class_highest = .; \
130 *(__stop_sched_class) \
131 *(__dl_sched_class) \
132 *(__rt_sched_class) \
133 *(__fair_sched_class) \
134 *(__idle_sched_class) \
135 __sched_class_lowest = .;
136
137/* The actual configuration determine if the init/exit sections
138 * are handled as text/data or they can be discarded (which
139 * often happens at runtime)
140 */
141
142#if defined(CONFIG_MEMORY_HOTPLUG)
143#define MEM_KEEP(sec) *(.mem##sec)
144#define MEM_DISCARD(sec)
145#else
146#define MEM_KEEP(sec)
147#define MEM_DISCARD(sec) *(.mem##sec)
148#endif
149
150#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
151#define KEEP_PATCHABLE KEEP(*(__patchable_function_entries))
152#define PATCHABLE_DISCARDS
153#else
154#define KEEP_PATCHABLE
155#define PATCHABLE_DISCARDS *(__patchable_function_entries)
156#endif
157
158#ifndef CONFIG_ARCH_SUPPORTS_CFI_CLANG
159/*
160 * Simply points to ftrace_stub, but with the proper protocol.
161 * Defined by the linker script in linux/vmlinux.lds.h
162 */
163#define FTRACE_STUB_HACK ftrace_stub_graph = ftrace_stub;
164#else
165#define FTRACE_STUB_HACK
166#endif
167
168#ifdef CONFIG_FTRACE_MCOUNT_RECORD
169/*
170 * The ftrace call sites are logged to a section whose name depends on the
171 * compiler option used. A given kernel image will only use one, AKA
172 * FTRACE_CALLSITE_SECTION. We capture all of them here to avoid header
173 * dependencies for FTRACE_CALLSITE_SECTION's definition.
174 *
175 * ftrace_ops_list_func will be defined as arch_ftrace_ops_list_func
176 * as some archs will have a different prototype for that function
177 * but ftrace_ops_list_func() will have a single prototype.
178 */
179#define MCOUNT_REC() . = ALIGN(8); \
180 __start_mcount_loc = .; \
181 KEEP(*(__mcount_loc)) \
182 KEEP_PATCHABLE \
183 __stop_mcount_loc = .; \
184 FTRACE_STUB_HACK \
185 ftrace_ops_list_func = arch_ftrace_ops_list_func;
186#else
187# ifdef CONFIG_FUNCTION_TRACER
188# define MCOUNT_REC() FTRACE_STUB_HACK \
189 ftrace_ops_list_func = arch_ftrace_ops_list_func;
190# else
191# define MCOUNT_REC()
192# endif
193#endif
194
195#define BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_) \
196 _BEGIN_##_label_ = .; \
197 KEEP(*(_sec_)) \
198 _END_##_label_ = .;
199
200#define BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_) \
201 _label_##_BEGIN_ = .; \
202 KEEP(*(_sec_)) \
203 _label_##_END_ = .;
204
205#define BOUNDED_SECTION_BY(_sec_, _label_) \
206 BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
207
208#define BOUNDED_SECTION(_sec) BOUNDED_SECTION_BY(_sec, _sec)
209
210#define HEADERED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
211 _HDR_##_label_ = .; \
212 KEEP(*(.gnu.linkonce.##_sec_)) \
213 BOUNDED_SECTION_PRE_LABEL(_sec_, _label_, _BEGIN_, _END_)
214
215#define HEADERED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_, _HDR_) \
216 _label_##_HDR_ = .; \
217 KEEP(*(.gnu.linkonce.##_sec_)) \
218 BOUNDED_SECTION_POST_LABEL(_sec_, _label_, _BEGIN_, _END_)
219
220#define HEADERED_SECTION_BY(_sec_, _label_) \
221 HEADERED_SECTION_PRE_LABEL(_sec_, _label_, __start, __stop)
222
223#define HEADERED_SECTION(_sec) HEADERED_SECTION_BY(_sec, _sec)
224
225#ifdef CONFIG_TRACE_BRANCH_PROFILING
226#define LIKELY_PROFILE() \
227 BOUNDED_SECTION_BY(_ftrace_annotated_branch, _annotated_branch_profile)
228#else
229#define LIKELY_PROFILE()
230#endif
231
232#ifdef CONFIG_PROFILE_ALL_BRANCHES
233#define BRANCH_PROFILE() \
234 BOUNDED_SECTION_BY(_ftrace_branch, _branch_profile)
235#else
236#define BRANCH_PROFILE()
237#endif
238
239#ifdef CONFIG_KPROBES
240#define KPROBE_BLACKLIST() \
241 . = ALIGN(8); \
242 BOUNDED_SECTION(_kprobe_blacklist)
243#else
244#define KPROBE_BLACKLIST()
245#endif
246
247#ifdef CONFIG_FUNCTION_ERROR_INJECTION
248#define ERROR_INJECT_WHITELIST() \
249 STRUCT_ALIGN(); \
250 BOUNDED_SECTION(_error_injection_whitelist)
251#else
252#define ERROR_INJECT_WHITELIST()
253#endif
254
255#ifdef CONFIG_EVENT_TRACING
256#define FTRACE_EVENTS() \
257 . = ALIGN(8); \
258 BOUNDED_SECTION(_ftrace_events) \
259 BOUNDED_SECTION_BY(_ftrace_eval_map, _ftrace_eval_maps)
260#else
261#define FTRACE_EVENTS()
262#endif
263
264#ifdef CONFIG_TRACING
265#define TRACE_PRINTKS() BOUNDED_SECTION_BY(__trace_printk_fmt, ___trace_bprintk_fmt)
266#define TRACEPOINT_STR() BOUNDED_SECTION_BY(__tracepoint_str, ___tracepoint_str)
267#else
268#define TRACE_PRINTKS()
269#define TRACEPOINT_STR()
270#endif
271
272#ifdef CONFIG_FTRACE_SYSCALLS
273#define TRACE_SYSCALLS() \
274 . = ALIGN(8); \
275 BOUNDED_SECTION_BY(__syscalls_metadata, _syscalls_metadata)
276#else
277#define TRACE_SYSCALLS()
278#endif
279
280#ifdef CONFIG_BPF_EVENTS
281#define BPF_RAW_TP() STRUCT_ALIGN(); \
282 BOUNDED_SECTION_BY(__bpf_raw_tp_map, __bpf_raw_tp)
283#else
284#define BPF_RAW_TP()
285#endif
286
287#ifdef CONFIG_SERIAL_EARLYCON
288#define EARLYCON_TABLE() \
289 . = ALIGN(8); \
290 BOUNDED_SECTION_POST_LABEL(__earlycon_table, __earlycon_table, , _end)
291#else
292#define EARLYCON_TABLE()
293#endif
294
295#ifdef CONFIG_SECURITY
296#define LSM_TABLE() \
297 . = ALIGN(8); \
298 BOUNDED_SECTION_PRE_LABEL(.lsm_info.init, _lsm_info, __start, __end)
299
300#define EARLY_LSM_TABLE() \
301 . = ALIGN(8); \
302 BOUNDED_SECTION_PRE_LABEL(.early_lsm_info.init, _early_lsm_info, __start, __end)
303#else
304#define LSM_TABLE()
305#define EARLY_LSM_TABLE()
306#endif
307
308#define ___OF_TABLE(cfg, name) _OF_TABLE_##cfg(name)
309#define __OF_TABLE(cfg, name) ___OF_TABLE(cfg, name)
310#define OF_TABLE(cfg, name) __OF_TABLE(IS_ENABLED(cfg), name)
311#define _OF_TABLE_0(name)
312#define _OF_TABLE_1(name) \
313 . = ALIGN(8); \
314 __##name##_of_table = .; \
315 KEEP(*(__##name##_of_table)) \
316 KEEP(*(__##name##_of_table_end))
317
318#define TIMER_OF_TABLES() OF_TABLE(CONFIG_TIMER_OF, timer)
319#define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip)
320#define CLK_OF_TABLES() OF_TABLE(CONFIG_COMMON_CLK, clk)
321#define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
322#define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method)
323#define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method)
324
325#ifdef CONFIG_ACPI
326#define ACPI_PROBE_TABLE(name) \
327 . = ALIGN(8); \
328 BOUNDED_SECTION_POST_LABEL(__##name##_acpi_probe_table, \
329 __##name##_acpi_probe_table,, _end)
330#else
331#define ACPI_PROBE_TABLE(name)
332#endif
333
334#ifdef CONFIG_THERMAL
335#define THERMAL_TABLE(name) \
336 . = ALIGN(8); \
337 BOUNDED_SECTION_POST_LABEL(__##name##_thermal_table, \
338 __##name##_thermal_table,, _end)
339#else
340#define THERMAL_TABLE(name)
341#endif
342
343#define KERNEL_DTB() \
344 STRUCT_ALIGN(); \
345 __dtb_start = .; \
346 KEEP(*(.dtb.init.rodata)) \
347 __dtb_end = .;
348
349/*
350 * .data section
351 */
352#define DATA_DATA \
353 *(.xiptext) \
354 *(DATA_MAIN) \
355 *(.data..decrypted) \
356 *(.ref.data) \
357 *(.data..shared_aligned) /* percpu related */ \
358 MEM_KEEP(init.data*) \
359 *(.data.unlikely) \
360 __start_once = .; \
361 *(.data.once) \
362 __end_once = .; \
363 STRUCT_ALIGN(); \
364 *(__tracepoints) \
365 /* implement dynamic printk debug */ \
366 . = ALIGN(8); \
367 BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes) \
368 BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \
369 LIKELY_PROFILE() \
370 BRANCH_PROFILE() \
371 TRACE_PRINTKS() \
372 BPF_RAW_TP() \
373 TRACEPOINT_STR() \
374 KUNIT_TABLE()
375
376/*
377 * Data section helpers
378 */
379#define NOSAVE_DATA \
380 . = ALIGN(PAGE_SIZE); \
381 __nosave_begin = .; \
382 *(.data..nosave) \
383 . = ALIGN(PAGE_SIZE); \
384 __nosave_end = .;
385
386#define PAGE_ALIGNED_DATA(page_align) \
387 . = ALIGN(page_align); \
388 *(.data..page_aligned) \
389 . = ALIGN(page_align);
390
391#define READ_MOSTLY_DATA(align) \
392 . = ALIGN(align); \
393 *(.data..read_mostly) \
394 . = ALIGN(align);
395
396#define CACHELINE_ALIGNED_DATA(align) \
397 . = ALIGN(align); \
398 *(.data..cacheline_aligned)
399
400#define INIT_TASK_DATA(align) \
401 . = ALIGN(align); \
402 __start_init_task = .; \
403 init_thread_union = .; \
404 init_stack = .; \
405 KEEP(*(.data..init_task)) \
406 KEEP(*(.data..init_thread_info)) \
407 . = __start_init_task + THREAD_SIZE; \
408 __end_init_task = .;
409
410#define JUMP_TABLE_DATA \
411 . = ALIGN(8); \
412 BOUNDED_SECTION_BY(__jump_table, ___jump_table)
413
414#ifdef CONFIG_HAVE_STATIC_CALL_INLINE
415#define STATIC_CALL_DATA \
416 . = ALIGN(8); \
417 BOUNDED_SECTION_BY(.static_call_sites, _static_call_sites) \
418 BOUNDED_SECTION_BY(.static_call_tramp_key, _static_call_tramp_key)
419#else
420#define STATIC_CALL_DATA
421#endif
422
423/*
424 * Allow architectures to handle ro_after_init data on their
425 * own by defining an empty RO_AFTER_INIT_DATA.
426 */
427#ifndef RO_AFTER_INIT_DATA
428#define RO_AFTER_INIT_DATA \
429 . = ALIGN(8); \
430 __start_ro_after_init = .; \
431 *(.data..ro_after_init) \
432 JUMP_TABLE_DATA \
433 STATIC_CALL_DATA \
434 __end_ro_after_init = .;
435#endif
436
437/*
438 * .kcfi_traps contains a list KCFI trap locations.
439 */
440#ifndef KCFI_TRAPS
441#ifdef CONFIG_ARCH_USES_CFI_TRAPS
442#define KCFI_TRAPS \
443 __kcfi_traps : AT(ADDR(__kcfi_traps) - LOAD_OFFSET) { \
444 BOUNDED_SECTION_BY(.kcfi_traps, ___kcfi_traps) \
445 }
446#else
447#define KCFI_TRAPS
448#endif
449#endif
450
451/*
452 * Read only Data
453 */
454#define RO_DATA(align) \
455 . = ALIGN((align)); \
456 .rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \
457 __start_rodata = .; \
458 *(.rodata) *(.rodata.*) \
459 SCHED_DATA \
460 RO_AFTER_INIT_DATA /* Read only after init */ \
461 . = ALIGN(8); \
462 BOUNDED_SECTION_BY(__tracepoints_ptrs, ___tracepoints_ptrs) \
463 *(__tracepoints_strings)/* Tracepoints: strings */ \
464 } \
465 \
466 .rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \
467 *(.rodata1) \
468 } \
469 \
470 /* PCI quirks */ \
471 .pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \
472 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_early, _pci_fixups_early, __start, __end) \
473 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_header, _pci_fixups_header, __start, __end) \
474 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_final, _pci_fixups_final, __start, __end) \
475 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_enable, _pci_fixups_enable, __start, __end) \
476 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_resume, _pci_fixups_resume, __start, __end) \
477 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_suspend, _pci_fixups_suspend, __start, __end) \
478 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_resume_early, _pci_fixups_resume_early, __start, __end) \
479 BOUNDED_SECTION_PRE_LABEL(.pci_fixup_suspend_late, _pci_fixups_suspend_late, __start, __end) \
480 } \
481 \
482 FW_LOADER_BUILT_IN_DATA \
483 TRACEDATA \
484 \
485 PRINTK_INDEX \
486 \
487 /* Kernel symbol table: Normal symbols */ \
488 __ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
489 __start___ksymtab = .; \
490 KEEP(*(SORT(___ksymtab+*))) \
491 __stop___ksymtab = .; \
492 } \
493 \
494 /* Kernel symbol table: GPL-only symbols */ \
495 __ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
496 __start___ksymtab_gpl = .; \
497 KEEP(*(SORT(___ksymtab_gpl+*))) \
498 __stop___ksymtab_gpl = .; \
499 } \
500 \
501 /* Kernel symbol table: Normal symbols */ \
502 __kcrctab : AT(ADDR(__kcrctab) - LOAD_OFFSET) { \
503 __start___kcrctab = .; \
504 KEEP(*(SORT(___kcrctab+*))) \
505 __stop___kcrctab = .; \
506 } \
507 \
508 /* Kernel symbol table: GPL-only symbols */ \
509 __kcrctab_gpl : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) { \
510 __start___kcrctab_gpl = .; \
511 KEEP(*(SORT(___kcrctab_gpl+*))) \
512 __stop___kcrctab_gpl = .; \
513 } \
514 \
515 /* Kernel symbol table: strings */ \
516 __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
517 *(__ksymtab_strings) \
518 } \
519 \
520 /* __*init sections */ \
521 __init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) { \
522 *(.ref.rodata) \
523 MEM_KEEP(init.rodata) \
524 } \
525 \
526 /* Built-in module parameters. */ \
527 __param : AT(ADDR(__param) - LOAD_OFFSET) { \
528 BOUNDED_SECTION_BY(__param, ___param) \
529 } \
530 \
531 /* Built-in module versions. */ \
532 __modver : AT(ADDR(__modver) - LOAD_OFFSET) { \
533 BOUNDED_SECTION_BY(__modver, ___modver) \
534 } \
535 \
536 KCFI_TRAPS \
537 \
538 RO_EXCEPTION_TABLE \
539 NOTES \
540 BTF \
541 \
542 . = ALIGN((align)); \
543 __end_rodata = .;
544
545
546/*
547 * Non-instrumentable text section
548 */
549#define NOINSTR_TEXT \
550 ALIGN_FUNCTION(); \
551 __noinstr_text_start = .; \
552 *(.noinstr.text) \
553 __cpuidle_text_start = .; \
554 *(.cpuidle.text) \
555 __cpuidle_text_end = .; \
556 __noinstr_text_end = .;
557
558/*
559 * .text section. Map to function alignment to avoid address changes
560 * during second ld run in second ld pass when generating System.map
561 *
562 * TEXT_MAIN here will match .text.fixup and .text.unlikely if dead
563 * code elimination is enabled, so these sections should be converted
564 * to use ".." first.
565 */
566#define TEXT_TEXT \
567 ALIGN_FUNCTION(); \
568 *(.text.hot .text.hot.*) \
569 *(TEXT_MAIN .text.fixup) \
570 *(.text.unlikely .text.unlikely.*) \
571 *(.text.unknown .text.unknown.*) \
572 NOINSTR_TEXT \
573 *(.ref.text) \
574 *(.text.asan.* .text.tsan.*) \
575 MEM_KEEP(init.text*) \
576
577
578/* sched.text is aling to function alignment to secure we have same
579 * address even at second ld pass when generating System.map */
580#define SCHED_TEXT \
581 ALIGN_FUNCTION(); \
582 __sched_text_start = .; \
583 *(.sched.text) \
584 __sched_text_end = .;
585
586/* spinlock.text is aling to function alignment to secure we have same
587 * address even at second ld pass when generating System.map */
588#define LOCK_TEXT \
589 ALIGN_FUNCTION(); \
590 __lock_text_start = .; \
591 *(.spinlock.text) \
592 __lock_text_end = .;
593
594#define KPROBES_TEXT \
595 ALIGN_FUNCTION(); \
596 __kprobes_text_start = .; \
597 *(.kprobes.text) \
598 __kprobes_text_end = .;
599
600#define ENTRY_TEXT \
601 ALIGN_FUNCTION(); \
602 __entry_text_start = .; \
603 *(.entry.text) \
604 __entry_text_end = .;
605
606#define IRQENTRY_TEXT \
607 ALIGN_FUNCTION(); \
608 __irqentry_text_start = .; \
609 *(.irqentry.text) \
610 __irqentry_text_end = .;
611
612#define SOFTIRQENTRY_TEXT \
613 ALIGN_FUNCTION(); \
614 __softirqentry_text_start = .; \
615 *(.softirqentry.text) \
616 __softirqentry_text_end = .;
617
618#define STATIC_CALL_TEXT \
619 ALIGN_FUNCTION(); \
620 __static_call_text_start = .; \
621 *(.static_call.text) \
622 __static_call_text_end = .;
623
624/* Section used for early init (in .S files) */
625#define HEAD_TEXT KEEP(*(.head.text))
626
627#define HEAD_TEXT_SECTION \
628 .head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { \
629 HEAD_TEXT \
630 }
631
632/*
633 * Exception table
634 */
635#define EXCEPTION_TABLE(align) \
636 . = ALIGN(align); \
637 __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \
638 BOUNDED_SECTION_BY(__ex_table, ___ex_table) \
639 }
640
641/*
642 * .BTF
643 */
644#ifdef CONFIG_DEBUG_INFO_BTF
645#define BTF \
646 .BTF : AT(ADDR(.BTF) - LOAD_OFFSET) { \
647 BOUNDED_SECTION_BY(.BTF, _BTF) \
648 } \
649 . = ALIGN(4); \
650 .BTF_ids : AT(ADDR(.BTF_ids) - LOAD_OFFSET) { \
651 *(.BTF_ids) \
652 }
653#else
654#define BTF
655#endif
656
657/*
658 * Init task
659 */
660#define INIT_TASK_DATA_SECTION(align) \
661 . = ALIGN(align); \
662 .data..init_task : AT(ADDR(.data..init_task) - LOAD_OFFSET) { \
663 INIT_TASK_DATA(align) \
664 }
665
666#ifdef CONFIG_CONSTRUCTORS
667#define KERNEL_CTORS() . = ALIGN(8); \
668 __ctors_start = .; \
669 KEEP(*(SORT(.ctors.*))) \
670 KEEP(*(.ctors)) \
671 KEEP(*(SORT(.init_array.*))) \
672 KEEP(*(.init_array)) \
673 __ctors_end = .;
674#else
675#define KERNEL_CTORS()
676#endif
677
678/* init and exit section handling */
679#define INIT_DATA \
680 KEEP(*(SORT(___kentry+*))) \
681 *(.init.data .init.data.*) \
682 MEM_DISCARD(init.data*) \
683 KERNEL_CTORS() \
684 MCOUNT_REC() \
685 *(.init.rodata .init.rodata.*) \
686 FTRACE_EVENTS() \
687 TRACE_SYSCALLS() \
688 KPROBE_BLACKLIST() \
689 ERROR_INJECT_WHITELIST() \
690 MEM_DISCARD(init.rodata) \
691 CLK_OF_TABLES() \
692 RESERVEDMEM_OF_TABLES() \
693 TIMER_OF_TABLES() \
694 CPU_METHOD_OF_TABLES() \
695 CPUIDLE_METHOD_OF_TABLES() \
696 KERNEL_DTB() \
697 IRQCHIP_OF_MATCH_TABLE() \
698 ACPI_PROBE_TABLE(irqchip) \
699 ACPI_PROBE_TABLE(timer) \
700 THERMAL_TABLE(governor) \
701 EARLYCON_TABLE() \
702 LSM_TABLE() \
703 EARLY_LSM_TABLE() \
704 KUNIT_INIT_TABLE()
705
706#define INIT_TEXT \
707 *(.init.text .init.text.*) \
708 *(.text.startup) \
709 MEM_DISCARD(init.text*)
710
711#define EXIT_DATA \
712 *(.exit.data .exit.data.*) \
713 *(.fini_array .fini_array.*) \
714 *(.dtors .dtors.*) \
715
716#define EXIT_TEXT \
717 *(.exit.text) \
718 *(.text.exit) \
719
720#define EXIT_CALL \
721 *(.exitcall.exit)
722
723/*
724 * bss (Block Started by Symbol) - uninitialized data
725 * zeroed during startup
726 */
727#define SBSS(sbss_align) \
728 . = ALIGN(sbss_align); \
729 .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \
730 *(.dynsbss) \
731 *(SBSS_MAIN) \
732 *(.scommon) \
733 }
734
735/*
736 * Allow archectures to redefine BSS_FIRST_SECTIONS to add extra
737 * sections to the front of bss.
738 */
739#ifndef BSS_FIRST_SECTIONS
740#define BSS_FIRST_SECTIONS
741#endif
742
743#define BSS(bss_align) \
744 . = ALIGN(bss_align); \
745 .bss : AT(ADDR(.bss) - LOAD_OFFSET) { \
746 BSS_FIRST_SECTIONS \
747 . = ALIGN(PAGE_SIZE); \
748 *(.bss..page_aligned) \
749 . = ALIGN(PAGE_SIZE); \
750 *(.dynbss) \
751 *(BSS_MAIN) \
752 *(COMMON) \
753 }
754
755/*
756 * DWARF debug sections.
757 * Symbols in the DWARF debugging sections are relative to
758 * the beginning of the section so we begin them at 0.
759 */
760#define DWARF_DEBUG \
761 /* DWARF 1 */ \
762 .debug 0 : { *(.debug) } \
763 .line 0 : { *(.line) } \
764 /* GNU DWARF 1 extensions */ \
765 .debug_srcinfo 0 : { *(.debug_srcinfo) } \
766 .debug_sfnames 0 : { *(.debug_sfnames) } \
767 /* DWARF 1.1 and DWARF 2 */ \
768 .debug_aranges 0 : { *(.debug_aranges) } \
769 .debug_pubnames 0 : { *(.debug_pubnames) } \
770 /* DWARF 2 */ \
771 .debug_info 0 : { *(.debug_info \
772 .gnu.linkonce.wi.*) } \
773 .debug_abbrev 0 : { *(.debug_abbrev) } \
774 .debug_line 0 : { *(.debug_line) } \
775 .debug_frame 0 : { *(.debug_frame) } \
776 .debug_str 0 : { *(.debug_str) } \
777 .debug_loc 0 : { *(.debug_loc) } \
778 .debug_macinfo 0 : { *(.debug_macinfo) } \
779 .debug_pubtypes 0 : { *(.debug_pubtypes) } \
780 /* DWARF 3 */ \
781 .debug_ranges 0 : { *(.debug_ranges) } \
782 /* SGI/MIPS DWARF 2 extensions */ \
783 .debug_weaknames 0 : { *(.debug_weaknames) } \
784 .debug_funcnames 0 : { *(.debug_funcnames) } \
785 .debug_typenames 0 : { *(.debug_typenames) } \
786 .debug_varnames 0 : { *(.debug_varnames) } \
787 /* GNU DWARF 2 extensions */ \
788 .debug_gnu_pubnames 0 : { *(.debug_gnu_pubnames) } \
789 .debug_gnu_pubtypes 0 : { *(.debug_gnu_pubtypes) } \
790 /* DWARF 4 */ \
791 .debug_types 0 : { *(.debug_types) } \
792 /* DWARF 5 */ \
793 .debug_addr 0 : { *(.debug_addr) } \
794 .debug_line_str 0 : { *(.debug_line_str) } \
795 .debug_loclists 0 : { *(.debug_loclists) } \
796 .debug_macro 0 : { *(.debug_macro) } \
797 .debug_names 0 : { *(.debug_names) } \
798 .debug_rnglists 0 : { *(.debug_rnglists) } \
799 .debug_str_offsets 0 : { *(.debug_str_offsets) }
800
801/* Stabs debugging sections. */
802#define STABS_DEBUG \
803 .stab 0 : { *(.stab) } \
804 .stabstr 0 : { *(.stabstr) } \
805 .stab.excl 0 : { *(.stab.excl) } \
806 .stab.exclstr 0 : { *(.stab.exclstr) } \
807 .stab.index 0 : { *(.stab.index) } \
808 .stab.indexstr 0 : { *(.stab.indexstr) }
809
810/* Required sections not related to debugging. */
811#define ELF_DETAILS \
812 .comment 0 : { *(.comment) } \
813 .symtab 0 : { *(.symtab) } \
814 .strtab 0 : { *(.strtab) } \
815 .shstrtab 0 : { *(.shstrtab) }
816
817#ifdef CONFIG_GENERIC_BUG
818#define BUG_TABLE \
819 . = ALIGN(8); \
820 __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \
821 BOUNDED_SECTION_BY(__bug_table, ___bug_table) \
822 }
823#else
824#define BUG_TABLE
825#endif
826
827#ifdef CONFIG_UNWINDER_ORC
828#define ORC_UNWIND_TABLE \
829 .orc_header : AT(ADDR(.orc_header) - LOAD_OFFSET) { \
830 BOUNDED_SECTION_BY(.orc_header, _orc_header) \
831 } \
832 . = ALIGN(4); \
833 .orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) { \
834 BOUNDED_SECTION_BY(.orc_unwind_ip, _orc_unwind_ip) \
835 } \
836 . = ALIGN(2); \
837 .orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) { \
838 BOUNDED_SECTION_BY(.orc_unwind, _orc_unwind) \
839 } \
840 text_size = _etext - _stext; \
841 . = ALIGN(4); \
842 .orc_lookup : AT(ADDR(.orc_lookup) - LOAD_OFFSET) { \
843 orc_lookup = .; \
844 . += (((text_size + LOOKUP_BLOCK_SIZE - 1) / \
845 LOOKUP_BLOCK_SIZE) + 1) * 4; \
846 orc_lookup_end = .; \
847 }
848#else
849#define ORC_UNWIND_TABLE
850#endif
851
852/* Built-in firmware blobs */
853#ifdef CONFIG_FW_LOADER
854#define FW_LOADER_BUILT_IN_DATA \
855 .builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) ALIGN(8) { \
856 BOUNDED_SECTION_PRE_LABEL(.builtin_fw, _builtin_fw, __start, __end) \
857 }
858#else
859#define FW_LOADER_BUILT_IN_DATA
860#endif
861
862#ifdef CONFIG_PM_TRACE
863#define TRACEDATA \
864 . = ALIGN(4); \
865 .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) { \
866 BOUNDED_SECTION_POST_LABEL(.tracedata, __tracedata, _start, _end) \
867 }
868#else
869#define TRACEDATA
870#endif
871
872#ifdef CONFIG_PRINTK_INDEX
873#define PRINTK_INDEX \
874 .printk_index : AT(ADDR(.printk_index) - LOAD_OFFSET) { \
875 BOUNDED_SECTION_BY(.printk_index, _printk_index) \
876 }
877#else
878#define PRINTK_INDEX
879#endif
880
881/*
882 * Discard .note.GNU-stack, which is emitted as PROGBITS by the compiler.
883 * Otherwise, the type of .notes section would become PROGBITS instead of NOTES.
884 *
885 * Also, discard .note.gnu.property, otherwise it forces the notes section to
886 * be 8-byte aligned which causes alignment mismatches with the kernel's custom
887 * 4-byte aligned notes.
888 */
889#define NOTES \
890 /DISCARD/ : { \
891 *(.note.GNU-stack) \
892 *(.note.gnu.property) \
893 } \
894 .notes : AT(ADDR(.notes) - LOAD_OFFSET) { \
895 BOUNDED_SECTION_BY(.note.*, _notes) \
896 } NOTES_HEADERS \
897 NOTES_HEADERS_RESTORE
898
899#define INIT_SETUP(initsetup_align) \
900 . = ALIGN(initsetup_align); \
901 BOUNDED_SECTION_POST_LABEL(.init.setup, __setup, _start, _end)
902
903#define INIT_CALLS_LEVEL(level) \
904 __initcall##level##_start = .; \
905 KEEP(*(.initcall##level##.init)) \
906 KEEP(*(.initcall##level##s.init)) \
907
908#define INIT_CALLS \
909 __initcall_start = .; \
910 KEEP(*(.initcallearly.init)) \
911 INIT_CALLS_LEVEL(0) \
912 INIT_CALLS_LEVEL(1) \
913 INIT_CALLS_LEVEL(2) \
914 INIT_CALLS_LEVEL(3) \
915 INIT_CALLS_LEVEL(4) \
916 INIT_CALLS_LEVEL(5) \
917 INIT_CALLS_LEVEL(rootfs) \
918 INIT_CALLS_LEVEL(6) \
919 INIT_CALLS_LEVEL(7) \
920 __initcall_end = .;
921
922#define CON_INITCALL \
923 BOUNDED_SECTION_POST_LABEL(.con_initcall.init, __con_initcall, _start, _end)
924
925/* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
926#define KUNIT_TABLE() \
927 . = ALIGN(8); \
928 BOUNDED_SECTION_POST_LABEL(.kunit_test_suites, __kunit_suites, _start, _end)
929
930/* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
931#define KUNIT_INIT_TABLE() \
932 . = ALIGN(8); \
933 BOUNDED_SECTION_POST_LABEL(.kunit_init_test_suites, \
934 __kunit_init_suites, _start, _end)
935
936#ifdef CONFIG_BLK_DEV_INITRD
937#define INIT_RAM_FS \
938 . = ALIGN(4); \
939 __initramfs_start = .; \
940 KEEP(*(.init.ramfs)) \
941 . = ALIGN(8); \
942 KEEP(*(.init.ramfs.info))
943#else
944#define INIT_RAM_FS
945#endif
946
947/*
948 * Memory encryption operates on a page basis. Since we need to clear
949 * the memory encryption mask for this section, it needs to be aligned
950 * on a page boundary and be a page-size multiple in length.
951 *
952 * Note: We use a separate section so that only this section gets
953 * decrypted to avoid exposing more than we wish.
954 */
955#ifdef CONFIG_AMD_MEM_ENCRYPT
956#define PERCPU_DECRYPTED_SECTION \
957 . = ALIGN(PAGE_SIZE); \
958 *(.data..percpu..decrypted) \
959 . = ALIGN(PAGE_SIZE);
960#else
961#define PERCPU_DECRYPTED_SECTION
962#endif
963
964
965/*
966 * Default discarded sections.
967 *
968 * Some archs want to discard exit text/data at runtime rather than
969 * link time due to cross-section references such as alt instructions,
970 * bug table, eh_frame, etc. DISCARDS must be the last of output
971 * section definitions so that such archs put those in earlier section
972 * definitions.
973 */
974#ifdef RUNTIME_DISCARD_EXIT
975#define EXIT_DISCARDS
976#else
977#define EXIT_DISCARDS \
978 EXIT_TEXT \
979 EXIT_DATA
980#endif
981
982/*
983 * Clang's -fprofile-arcs, -fsanitize=kernel-address, and
984 * -fsanitize=thread produce unwanted sections (.eh_frame
985 * and .init_array.*), but CONFIG_CONSTRUCTORS wants to
986 * keep any .init_array.* sections.
987 * https://llvm.org/pr46478
988 */
989#ifdef CONFIG_UNWIND_TABLES
990#define DISCARD_EH_FRAME
991#else
992#define DISCARD_EH_FRAME *(.eh_frame)
993#endif
994#if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN)
995# ifdef CONFIG_CONSTRUCTORS
996# define SANITIZER_DISCARDS \
997 DISCARD_EH_FRAME
998# else
999# define SANITIZER_DISCARDS \
1000 *(.init_array) *(.init_array.*) \
1001 DISCARD_EH_FRAME
1002# endif
1003#else
1004# define SANITIZER_DISCARDS
1005#endif
1006
1007#define COMMON_DISCARDS \
1008 SANITIZER_DISCARDS \
1009 PATCHABLE_DISCARDS \
1010 *(.discard) \
1011 *(.discard.*) \
1012 *(.export_symbol) \
1013 *(.modinfo) \
1014 /* ld.bfd warns about .gnu.version* even when not emitted */ \
1015 *(.gnu.version*) \
1016
1017#define DISCARDS \
1018 /DISCARD/ : { \
1019 EXIT_DISCARDS \
1020 EXIT_CALL \
1021 COMMON_DISCARDS \
1022 }
1023
1024/**
1025 * PERCPU_INPUT - the percpu input sections
1026 * @cacheline: cacheline size
1027 *
1028 * The core percpu section names and core symbols which do not rely
1029 * directly upon load addresses.
1030 *
1031 * @cacheline is used to align subsections to avoid false cacheline
1032 * sharing between subsections for different purposes.
1033 */
1034#define PERCPU_INPUT(cacheline) \
1035 __per_cpu_start = .; \
1036 *(.data..percpu..first) \
1037 . = ALIGN(PAGE_SIZE); \
1038 *(.data..percpu..page_aligned) \
1039 . = ALIGN(cacheline); \
1040 *(.data..percpu..read_mostly) \
1041 . = ALIGN(cacheline); \
1042 *(.data..percpu) \
1043 *(.data..percpu..shared_aligned) \
1044 PERCPU_DECRYPTED_SECTION \
1045 __per_cpu_end = .;
1046
1047/**
1048 * PERCPU_VADDR - define output section for percpu area
1049 * @cacheline: cacheline size
1050 * @vaddr: explicit base address (optional)
1051 * @phdr: destination PHDR (optional)
1052 *
1053 * Macro which expands to output section for percpu area.
1054 *
1055 * @cacheline is used to align subsections to avoid false cacheline
1056 * sharing between subsections for different purposes.
1057 *
1058 * If @vaddr is not blank, it specifies explicit base address and all
1059 * percpu symbols will be offset from the given address. If blank,
1060 * @vaddr always equals @laddr + LOAD_OFFSET.
1061 *
1062 * @phdr defines the output PHDR to use if not blank. Be warned that
1063 * output PHDR is sticky. If @phdr is specified, the next output
1064 * section in the linker script will go there too. @phdr should have
1065 * a leading colon.
1066 *
1067 * Note that this macros defines __per_cpu_load as an absolute symbol.
1068 * If there is no need to put the percpu section at a predetermined
1069 * address, use PERCPU_SECTION.
1070 */
1071#define PERCPU_VADDR(cacheline, vaddr, phdr) \
1072 __per_cpu_load = .; \
1073 .data..percpu vaddr : AT(__per_cpu_load - LOAD_OFFSET) { \
1074 PERCPU_INPUT(cacheline) \
1075 } phdr \
1076 . = __per_cpu_load + SIZEOF(.data..percpu);
1077
1078/**
1079 * PERCPU_SECTION - define output section for percpu area, simple version
1080 * @cacheline: cacheline size
1081 *
1082 * Align to PAGE_SIZE and outputs output section for percpu area. This
1083 * macro doesn't manipulate @vaddr or @phdr and __per_cpu_load and
1084 * __per_cpu_start will be identical.
1085 *
1086 * This macro is equivalent to ALIGN(PAGE_SIZE); PERCPU_VADDR(@cacheline,,)
1087 * except that __per_cpu_load is defined as a relative symbol against
1088 * .data..percpu which is required for relocatable x86_32 configuration.
1089 */
1090#define PERCPU_SECTION(cacheline) \
1091 . = ALIGN(PAGE_SIZE); \
1092 .data..percpu : AT(ADDR(.data..percpu) - LOAD_OFFSET) { \
1093 __per_cpu_load = .; \
1094 PERCPU_INPUT(cacheline) \
1095 }
1096
1097
1098/*
1099 * Definition of the high level *_SECTION macros
1100 * They will fit only a subset of the architectures
1101 */
1102
1103
1104/*
1105 * Writeable data.
1106 * All sections are combined in a single .data section.
1107 * The sections following CONSTRUCTORS are arranged so their
1108 * typical alignment matches.
1109 * A cacheline is typical/always less than a PAGE_SIZE so
1110 * the sections that has this restriction (or similar)
1111 * is located before the ones requiring PAGE_SIZE alignment.
1112 * NOSAVE_DATA starts and ends with a PAGE_SIZE alignment which
1113 * matches the requirement of PAGE_ALIGNED_DATA.
1114 *
1115 * use 0 as page_align if page_aligned data is not used */
1116#define RW_DATA(cacheline, pagealigned, inittask) \
1117 . = ALIGN(PAGE_SIZE); \
1118 .data : AT(ADDR(.data) - LOAD_OFFSET) { \
1119 INIT_TASK_DATA(inittask) \
1120 NOSAVE_DATA \
1121 PAGE_ALIGNED_DATA(pagealigned) \
1122 CACHELINE_ALIGNED_DATA(cacheline) \
1123 READ_MOSTLY_DATA(cacheline) \
1124 DATA_DATA \
1125 CONSTRUCTORS \
1126 } \
1127 BUG_TABLE \
1128
1129#define INIT_TEXT_SECTION(inittext_align) \
1130 . = ALIGN(inittext_align); \
1131 .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { \
1132 _sinittext = .; \
1133 INIT_TEXT \
1134 _einittext = .; \
1135 }
1136
1137#define INIT_DATA_SECTION(initsetup_align) \
1138 .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { \
1139 INIT_DATA \
1140 INIT_SETUP(initsetup_align) \
1141 INIT_CALLS \
1142 CON_INITCALL \
1143 INIT_RAM_FS \
1144 }
1145
1146#define BSS_SECTION(sbss_align, bss_align, stop_align) \
1147 . = ALIGN(sbss_align); \
1148 __bss_start = .; \
1149 SBSS(sbss_align) \
1150 BSS(bss_align) \
1151 . = ALIGN(stop_align); \
1152 __bss_stop = .;
1153

source code of linux/include/asm-generic/vmlinux.lds.h