xref: /linux/include/asm-generic/vmlinux.lds.h (revision 4f58e6dceb0e44ca8f21568ed81e1df24e55964c)
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_SECTION(PAGE_SIZE)
27  *	RW_DATA_SECTION(...)
28  *	_edata = .;
29  *
30  *	EXCEPTION_TABLE(...)
31  *	NOTES
32  *
33  *	BSS_SECTION(0, 0, 0)
34  *	_end = .;
35  *
36  *	STABS_DEBUG
37  *	DWARF_DEBUG
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 #include <linux/export.h>
58 
59 /* Align . to a 8 byte boundary equals to maximum function alignment. */
60 #define ALIGN_FUNCTION()  . = ALIGN(8)
61 
62 /*
63  * Align to a 32 byte boundary equal to the
64  * alignment gcc 4.5 uses for a struct
65  */
66 #define STRUCT_ALIGNMENT 32
67 #define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
68 
69 /* The actual configuration determine if the init/exit sections
70  * are handled as text/data or they can be discarded (which
71  * often happens at runtime)
72  */
73 #ifdef CONFIG_HOTPLUG_CPU
74 #define CPU_KEEP(sec)    *(.cpu##sec)
75 #define CPU_DISCARD(sec)
76 #else
77 #define CPU_KEEP(sec)
78 #define CPU_DISCARD(sec) *(.cpu##sec)
79 #endif
80 
81 #if defined(CONFIG_MEMORY_HOTPLUG)
82 #define MEM_KEEP(sec)    *(.mem##sec)
83 #define MEM_DISCARD(sec)
84 #else
85 #define MEM_KEEP(sec)
86 #define MEM_DISCARD(sec) *(.mem##sec)
87 #endif
88 
89 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
90 #define MCOUNT_REC()	. = ALIGN(8);				\
91 			VMLINUX_SYMBOL(__start_mcount_loc) = .; \
92 			*(__mcount_loc)				\
93 			VMLINUX_SYMBOL(__stop_mcount_loc) = .;
94 #else
95 #define MCOUNT_REC()
96 #endif
97 
98 #ifdef CONFIG_TRACE_BRANCH_PROFILING
99 #define LIKELY_PROFILE()	VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
100 				*(_ftrace_annotated_branch)			      \
101 				VMLINUX_SYMBOL(__stop_annotated_branch_profile) = .;
102 #else
103 #define LIKELY_PROFILE()
104 #endif
105 
106 #ifdef CONFIG_PROFILE_ALL_BRANCHES
107 #define BRANCH_PROFILE()	VMLINUX_SYMBOL(__start_branch_profile) = .;   \
108 				*(_ftrace_branch)			      \
109 				VMLINUX_SYMBOL(__stop_branch_profile) = .;
110 #else
111 #define BRANCH_PROFILE()
112 #endif
113 
114 #ifdef CONFIG_KPROBES
115 #define KPROBE_BLACKLIST()	. = ALIGN(8);				      \
116 				VMLINUX_SYMBOL(__start_kprobe_blacklist) = .; \
117 				*(_kprobe_blacklist)			      \
118 				VMLINUX_SYMBOL(__stop_kprobe_blacklist) = .;
119 #else
120 #define KPROBE_BLACKLIST()
121 #endif
122 
123 #ifdef CONFIG_EVENT_TRACING
124 #define FTRACE_EVENTS()	. = ALIGN(8);					\
125 			VMLINUX_SYMBOL(__start_ftrace_events) = .;	\
126 			*(_ftrace_events)				\
127 			VMLINUX_SYMBOL(__stop_ftrace_events) = .;	\
128 			VMLINUX_SYMBOL(__start_ftrace_enum_maps) = .;	\
129 			*(_ftrace_enum_map)				\
130 			VMLINUX_SYMBOL(__stop_ftrace_enum_maps) = .;
131 #else
132 #define FTRACE_EVENTS()
133 #endif
134 
135 #ifdef CONFIG_TRACING
136 #define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;      \
137 			 *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
138 			 VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
139 #define TRACEPOINT_STR() VMLINUX_SYMBOL(__start___tracepoint_str) = .;	\
140 			 *(__tracepoint_str) /* Trace_printk fmt' pointer */ \
141 			 VMLINUX_SYMBOL(__stop___tracepoint_str) = .;
142 #else
143 #define TRACE_PRINTKS()
144 #define TRACEPOINT_STR()
145 #endif
146 
147 #ifdef CONFIG_FTRACE_SYSCALLS
148 #define TRACE_SYSCALLS() . = ALIGN(8);					\
149 			 VMLINUX_SYMBOL(__start_syscalls_metadata) = .;	\
150 			 *(__syscalls_metadata)				\
151 			 VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
152 #else
153 #define TRACE_SYSCALLS()
154 #endif
155 
156 #ifdef CONFIG_SERIAL_EARLYCON
157 #define EARLYCON_TABLE() STRUCT_ALIGN();			\
158 			 VMLINUX_SYMBOL(__earlycon_table) = .;	\
159 			 *(__earlycon_table)			\
160 			 VMLINUX_SYMBOL(__earlycon_table_end) = .;
161 #else
162 #define EARLYCON_TABLE()
163 #endif
164 
165 #define ___OF_TABLE(cfg, name)	_OF_TABLE_##cfg(name)
166 #define __OF_TABLE(cfg, name)	___OF_TABLE(cfg, name)
167 #define OF_TABLE(cfg, name)	__OF_TABLE(IS_ENABLED(cfg), name)
168 #define _OF_TABLE_0(name)
169 #define _OF_TABLE_1(name)						\
170 	. = ALIGN(8);							\
171 	VMLINUX_SYMBOL(__##name##_of_table) = .;			\
172 	*(__##name##_of_table)						\
173 	*(__##name##_of_table_end)
174 
175 #define CLKSRC_OF_TABLES()	OF_TABLE(CONFIG_CLKSRC_OF, clksrc)
176 #define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip)
177 #define CLK_OF_TABLES()		OF_TABLE(CONFIG_COMMON_CLK, clk)
178 #define IOMMU_OF_TABLES()	OF_TABLE(CONFIG_OF_IOMMU, iommu)
179 #define RESERVEDMEM_OF_TABLES()	OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
180 #define CPU_METHOD_OF_TABLES()	OF_TABLE(CONFIG_SMP, cpu_method)
181 #define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method)
182 
183 #ifdef CONFIG_ACPI
184 #define ACPI_PROBE_TABLE(name)						\
185 	. = ALIGN(8);							\
186 	VMLINUX_SYMBOL(__##name##_acpi_probe_table) = .;		\
187 	*(__##name##_acpi_probe_table)					\
188 	VMLINUX_SYMBOL(__##name##_acpi_probe_table_end) = .;
189 #else
190 #define ACPI_PROBE_TABLE(name)
191 #endif
192 
193 #define KERNEL_DTB()							\
194 	STRUCT_ALIGN();							\
195 	VMLINUX_SYMBOL(__dtb_start) = .;				\
196 	*(.dtb.init.rodata)						\
197 	VMLINUX_SYMBOL(__dtb_end) = .;
198 
199 /* .data section */
200 #define DATA_DATA							\
201 	*(.data)							\
202 	*(.ref.data)							\
203 	*(.data..shared_aligned) /* percpu related */			\
204 	MEM_KEEP(init.data)						\
205 	MEM_KEEP(exit.data)						\
206 	*(.data.unlikely)						\
207 	STRUCT_ALIGN();							\
208 	*(__tracepoints)						\
209 	/* implement dynamic printk debug */				\
210 	. = ALIGN(8);                                                   \
211 	VMLINUX_SYMBOL(__start___jump_table) = .;                       \
212 	*(__jump_table)                                                 \
213 	VMLINUX_SYMBOL(__stop___jump_table) = .;                        \
214 	. = ALIGN(8);							\
215 	VMLINUX_SYMBOL(__start___verbose) = .;                          \
216 	*(__verbose)                                                    \
217 	VMLINUX_SYMBOL(__stop___verbose) = .;				\
218 	LIKELY_PROFILE()		       				\
219 	BRANCH_PROFILE()						\
220 	TRACE_PRINTKS()							\
221 	TRACEPOINT_STR()
222 
223 /*
224  * Data section helpers
225  */
226 #define NOSAVE_DATA							\
227 	. = ALIGN(PAGE_SIZE);						\
228 	VMLINUX_SYMBOL(__nosave_begin) = .;				\
229 	*(.data..nosave)						\
230 	. = ALIGN(PAGE_SIZE);						\
231 	VMLINUX_SYMBOL(__nosave_end) = .;
232 
233 #define PAGE_ALIGNED_DATA(page_align)					\
234 	. = ALIGN(page_align);						\
235 	*(.data..page_aligned)
236 
237 #define READ_MOSTLY_DATA(align)						\
238 	. = ALIGN(align);						\
239 	*(.data..read_mostly)						\
240 	. = ALIGN(align);
241 
242 #define CACHELINE_ALIGNED_DATA(align)					\
243 	. = ALIGN(align);						\
244 	*(.data..cacheline_aligned)
245 
246 #define INIT_TASK_DATA(align)						\
247 	. = ALIGN(align);						\
248 	VMLINUX_SYMBOL(__start_init_task) = .;				\
249 	*(.data..init_task)						\
250 	VMLINUX_SYMBOL(__end_init_task) = .;
251 
252 /*
253  * Allow architectures to handle ro_after_init data on their
254  * own by defining an empty RO_AFTER_INIT_DATA.
255  */
256 #ifndef RO_AFTER_INIT_DATA
257 #define RO_AFTER_INIT_DATA *(.data..ro_after_init)
258 #endif
259 
260 /*
261  * Read only Data
262  */
263 #define RO_DATA_SECTION(align)						\
264 	. = ALIGN((align));						\
265 	.rodata           : AT(ADDR(.rodata) - LOAD_OFFSET) {		\
266 		VMLINUX_SYMBOL(__start_rodata) = .;			\
267 		*(.rodata) *(.rodata.*)					\
268 		RO_AFTER_INIT_DATA	/* Read only after init */	\
269 		*(__vermagic)		/* Kernel version magic */	\
270 		. = ALIGN(8);						\
271 		VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .;		\
272 		*(__tracepoints_ptrs)	/* Tracepoints: pointer array */\
273 		VMLINUX_SYMBOL(__stop___tracepoints_ptrs) = .;		\
274 		*(__tracepoints_strings)/* Tracepoints: strings */	\
275 	}								\
276 									\
277 	.rodata1          : AT(ADDR(.rodata1) - LOAD_OFFSET) {		\
278 		*(.rodata1)						\
279 	}								\
280 									\
281 	BUG_TABLE							\
282 									\
283 	/* PCI quirks */						\
284 	.pci_fixup        : AT(ADDR(.pci_fixup) - LOAD_OFFSET) {	\
285 		VMLINUX_SYMBOL(__start_pci_fixups_early) = .;		\
286 		*(.pci_fixup_early)					\
287 		VMLINUX_SYMBOL(__end_pci_fixups_early) = .;		\
288 		VMLINUX_SYMBOL(__start_pci_fixups_header) = .;		\
289 		*(.pci_fixup_header)					\
290 		VMLINUX_SYMBOL(__end_pci_fixups_header) = .;		\
291 		VMLINUX_SYMBOL(__start_pci_fixups_final) = .;		\
292 		*(.pci_fixup_final)					\
293 		VMLINUX_SYMBOL(__end_pci_fixups_final) = .;		\
294 		VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;		\
295 		*(.pci_fixup_enable)					\
296 		VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;		\
297 		VMLINUX_SYMBOL(__start_pci_fixups_resume) = .;		\
298 		*(.pci_fixup_resume)					\
299 		VMLINUX_SYMBOL(__end_pci_fixups_resume) = .;		\
300 		VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .;	\
301 		*(.pci_fixup_resume_early)				\
302 		VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .;	\
303 		VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .;		\
304 		*(.pci_fixup_suspend)					\
305 		VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .;		\
306 		VMLINUX_SYMBOL(__start_pci_fixups_suspend_late) = .;	\
307 		*(.pci_fixup_suspend_late)				\
308 		VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .;	\
309 	}								\
310 									\
311 	/* Built-in firmware blobs */					\
312 	.builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {	\
313 		VMLINUX_SYMBOL(__start_builtin_fw) = .;			\
314 		*(.builtin_fw)						\
315 		VMLINUX_SYMBOL(__end_builtin_fw) = .;			\
316 	}								\
317 									\
318 	TRACEDATA							\
319 									\
320 	/* Kernel symbol table: Normal symbols */			\
321 	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\
322 		VMLINUX_SYMBOL(__start___ksymtab) = .;			\
323 		*(SORT(___ksymtab+*))					\
324 		VMLINUX_SYMBOL(__stop___ksymtab) = .;			\
325 	}								\
326 									\
327 	/* Kernel symbol table: GPL-only symbols */			\
328 	__ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {	\
329 		VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;		\
330 		*(SORT(___ksymtab_gpl+*))				\
331 		VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;		\
332 	}								\
333 									\
334 	/* Kernel symbol table: Normal unused symbols */		\
335 	__ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {	\
336 		VMLINUX_SYMBOL(__start___ksymtab_unused) = .;		\
337 		*(SORT(___ksymtab_unused+*))				\
338 		VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;		\
339 	}								\
340 									\
341 	/* Kernel symbol table: GPL-only unused symbols */		\
342 	__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
343 		VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;	\
344 		*(SORT(___ksymtab_unused_gpl+*))			\
345 		VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;	\
346 	}								\
347 									\
348 	/* Kernel symbol table: GPL-future-only symbols */		\
349 	__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
350 		VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;	\
351 		*(SORT(___ksymtab_gpl_future+*))			\
352 		VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;	\
353 	}								\
354 									\
355 	/* Kernel symbol table: Normal symbols */			\
356 	__kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {		\
357 		VMLINUX_SYMBOL(__start___kcrctab) = .;			\
358 		*(SORT(___kcrctab+*))					\
359 		VMLINUX_SYMBOL(__stop___kcrctab) = .;			\
360 	}								\
361 									\
362 	/* Kernel symbol table: GPL-only symbols */			\
363 	__kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {	\
364 		VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;		\
365 		*(SORT(___kcrctab_gpl+*))				\
366 		VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;		\
367 	}								\
368 									\
369 	/* Kernel symbol table: Normal unused symbols */		\
370 	__kcrctab_unused  : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) {	\
371 		VMLINUX_SYMBOL(__start___kcrctab_unused) = .;		\
372 		*(SORT(___kcrctab_unused+*))				\
373 		VMLINUX_SYMBOL(__stop___kcrctab_unused) = .;		\
374 	}								\
375 									\
376 	/* Kernel symbol table: GPL-only unused symbols */		\
377 	__kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
378 		VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;	\
379 		*(SORT(___kcrctab_unused_gpl+*))			\
380 		VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;	\
381 	}								\
382 									\
383 	/* Kernel symbol table: GPL-future-only symbols */		\
384 	__kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
385 		VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;	\
386 		*(SORT(___kcrctab_gpl_future+*))			\
387 		VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;	\
388 	}								\
389 									\
390 	/* Kernel symbol table: strings */				\
391         __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) {	\
392 		*(__ksymtab_strings)					\
393 	}								\
394 									\
395 	/* __*init sections */						\
396 	__init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) {		\
397 		*(.ref.rodata)						\
398 		MEM_KEEP(init.rodata)					\
399 		MEM_KEEP(exit.rodata)					\
400 	}								\
401 									\
402 	/* Built-in module parameters. */				\
403 	__param : AT(ADDR(__param) - LOAD_OFFSET) {			\
404 		VMLINUX_SYMBOL(__start___param) = .;			\
405 		*(__param)						\
406 		VMLINUX_SYMBOL(__stop___param) = .;			\
407 	}								\
408 									\
409 	/* Built-in module versions. */					\
410 	__modver : AT(ADDR(__modver) - LOAD_OFFSET) {			\
411 		VMLINUX_SYMBOL(__start___modver) = .;			\
412 		*(__modver)						\
413 		VMLINUX_SYMBOL(__stop___modver) = .;			\
414 		. = ALIGN((align));					\
415 		VMLINUX_SYMBOL(__end_rodata) = .;			\
416 	}								\
417 	. = ALIGN((align));
418 
419 /* RODATA & RO_DATA provided for backward compatibility.
420  * All archs are supposed to use RO_DATA() */
421 #define RODATA          RO_DATA_SECTION(4096)
422 #define RO_DATA(align)  RO_DATA_SECTION(align)
423 
424 #define SECURITY_INIT							\
425 	.security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \
426 		VMLINUX_SYMBOL(__security_initcall_start) = .;		\
427 		*(.security_initcall.init) 				\
428 		VMLINUX_SYMBOL(__security_initcall_end) = .;		\
429 	}
430 
431 /* .text section. Map to function alignment to avoid address changes
432  * during second ld run in second ld pass when generating System.map */
433 #define TEXT_TEXT							\
434 		ALIGN_FUNCTION();					\
435 		*(.text.hot .text .text.fixup .text.unlikely)		\
436 		*(.ref.text)						\
437 	MEM_KEEP(init.text)						\
438 	MEM_KEEP(exit.text)						\
439 
440 
441 /* sched.text is aling to function alignment to secure we have same
442  * address even at second ld pass when generating System.map */
443 #define SCHED_TEXT							\
444 		ALIGN_FUNCTION();					\
445 		VMLINUX_SYMBOL(__sched_text_start) = .;			\
446 		*(.sched.text)						\
447 		VMLINUX_SYMBOL(__sched_text_end) = .;
448 
449 /* spinlock.text is aling to function alignment to secure we have same
450  * address even at second ld pass when generating System.map */
451 #define LOCK_TEXT							\
452 		ALIGN_FUNCTION();					\
453 		VMLINUX_SYMBOL(__lock_text_start) = .;			\
454 		*(.spinlock.text)					\
455 		VMLINUX_SYMBOL(__lock_text_end) = .;
456 
457 #define CPUIDLE_TEXT							\
458 		ALIGN_FUNCTION();					\
459 		VMLINUX_SYMBOL(__cpuidle_text_start) = .;		\
460 		*(.cpuidle.text)					\
461 		VMLINUX_SYMBOL(__cpuidle_text_end) = .;
462 
463 #define KPROBES_TEXT							\
464 		ALIGN_FUNCTION();					\
465 		VMLINUX_SYMBOL(__kprobes_text_start) = .;		\
466 		*(.kprobes.text)					\
467 		VMLINUX_SYMBOL(__kprobes_text_end) = .;
468 
469 #define ENTRY_TEXT							\
470 		ALIGN_FUNCTION();					\
471 		VMLINUX_SYMBOL(__entry_text_start) = .;			\
472 		*(.entry.text)						\
473 		VMLINUX_SYMBOL(__entry_text_end) = .;
474 
475 #if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
476 #define IRQENTRY_TEXT							\
477 		ALIGN_FUNCTION();					\
478 		VMLINUX_SYMBOL(__irqentry_text_start) = .;		\
479 		*(.irqentry.text)					\
480 		VMLINUX_SYMBOL(__irqentry_text_end) = .;
481 #else
482 #define IRQENTRY_TEXT
483 #endif
484 
485 #if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
486 #define SOFTIRQENTRY_TEXT						\
487 		ALIGN_FUNCTION();					\
488 		VMLINUX_SYMBOL(__softirqentry_text_start) = .;		\
489 		*(.softirqentry.text)					\
490 		VMLINUX_SYMBOL(__softirqentry_text_end) = .;
491 #else
492 #define SOFTIRQENTRY_TEXT
493 #endif
494 
495 /* Section used for early init (in .S files) */
496 #define HEAD_TEXT  *(.head.text)
497 
498 #define HEAD_TEXT_SECTION							\
499 	.head.text : AT(ADDR(.head.text) - LOAD_OFFSET) {		\
500 		HEAD_TEXT						\
501 	}
502 
503 /*
504  * Exception table
505  */
506 #define EXCEPTION_TABLE(align)						\
507 	. = ALIGN(align);						\
508 	__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {		\
509 		VMLINUX_SYMBOL(__start___ex_table) = .;			\
510 		*(__ex_table)						\
511 		VMLINUX_SYMBOL(__stop___ex_table) = .;			\
512 	}
513 
514 /*
515  * Init task
516  */
517 #define INIT_TASK_DATA_SECTION(align)					\
518 	. = ALIGN(align);						\
519 	.data..init_task :  AT(ADDR(.data..init_task) - LOAD_OFFSET) {	\
520 		INIT_TASK_DATA(align)					\
521 	}
522 
523 #ifdef CONFIG_CONSTRUCTORS
524 #define KERNEL_CTORS()	. = ALIGN(8);			   \
525 			VMLINUX_SYMBOL(__ctors_start) = .; \
526 			*(.ctors)			   \
527 			*(SORT(.init_array.*))		   \
528 			*(.init_array)			   \
529 			VMLINUX_SYMBOL(__ctors_end) = .;
530 #else
531 #define KERNEL_CTORS()
532 #endif
533 
534 /* init and exit section handling */
535 #define INIT_DATA							\
536 	*(.init.data)							\
537 	MEM_DISCARD(init.data)						\
538 	KERNEL_CTORS()							\
539 	MCOUNT_REC()							\
540 	*(.init.rodata)							\
541 	FTRACE_EVENTS()							\
542 	TRACE_SYSCALLS()						\
543 	KPROBE_BLACKLIST()						\
544 	MEM_DISCARD(init.rodata)					\
545 	CLK_OF_TABLES()							\
546 	RESERVEDMEM_OF_TABLES()						\
547 	CLKSRC_OF_TABLES()						\
548 	IOMMU_OF_TABLES()						\
549 	CPU_METHOD_OF_TABLES()						\
550 	CPUIDLE_METHOD_OF_TABLES()					\
551 	KERNEL_DTB()							\
552 	IRQCHIP_OF_MATCH_TABLE()					\
553 	ACPI_PROBE_TABLE(irqchip)					\
554 	ACPI_PROBE_TABLE(clksrc)					\
555 	EARLYCON_TABLE()
556 
557 #define INIT_TEXT							\
558 	*(.init.text)							\
559 	*(.text.startup)						\
560 	MEM_DISCARD(init.text)
561 
562 #define EXIT_DATA							\
563 	*(.exit.data)							\
564 	*(.fini_array)							\
565 	*(.dtors)							\
566 	MEM_DISCARD(exit.data)						\
567 	MEM_DISCARD(exit.rodata)
568 
569 #define EXIT_TEXT							\
570 	*(.exit.text)							\
571 	*(.text.exit)							\
572 	MEM_DISCARD(exit.text)
573 
574 #define EXIT_CALL							\
575 	*(.exitcall.exit)
576 
577 /*
578  * bss (Block Started by Symbol) - uninitialized data
579  * zeroed during startup
580  */
581 #define SBSS(sbss_align)						\
582 	. = ALIGN(sbss_align);						\
583 	.sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {				\
584 		*(.sbss)						\
585 		*(.scommon)						\
586 	}
587 
588 /*
589  * Allow archectures to redefine BSS_FIRST_SECTIONS to add extra
590  * sections to the front of bss.
591  */
592 #ifndef BSS_FIRST_SECTIONS
593 #define BSS_FIRST_SECTIONS
594 #endif
595 
596 #define BSS(bss_align)							\
597 	. = ALIGN(bss_align);						\
598 	.bss : AT(ADDR(.bss) - LOAD_OFFSET) {				\
599 		BSS_FIRST_SECTIONS					\
600 		*(.bss..page_aligned)					\
601 		*(.dynbss)						\
602 		*(.bss)							\
603 		*(COMMON)						\
604 	}
605 
606 /*
607  * DWARF debug sections.
608  * Symbols in the DWARF debugging sections are relative to
609  * the beginning of the section so we begin them at 0.
610  */
611 #define DWARF_DEBUG							\
612 		/* DWARF 1 */						\
613 		.debug          0 : { *(.debug) }			\
614 		.line           0 : { *(.line) }			\
615 		/* GNU DWARF 1 extensions */				\
616 		.debug_srcinfo  0 : { *(.debug_srcinfo) }		\
617 		.debug_sfnames  0 : { *(.debug_sfnames) }		\
618 		/* DWARF 1.1 and DWARF 2 */				\
619 		.debug_aranges  0 : { *(.debug_aranges) }		\
620 		.debug_pubnames 0 : { *(.debug_pubnames) }		\
621 		/* DWARF 2 */						\
622 		.debug_info     0 : { *(.debug_info			\
623 				.gnu.linkonce.wi.*) }			\
624 		.debug_abbrev   0 : { *(.debug_abbrev) }		\
625 		.debug_line     0 : { *(.debug_line) }			\
626 		.debug_frame    0 : { *(.debug_frame) }			\
627 		.debug_str      0 : { *(.debug_str) }			\
628 		.debug_loc      0 : { *(.debug_loc) }			\
629 		.debug_macinfo  0 : { *(.debug_macinfo) }		\
630 		/* SGI/MIPS DWARF 2 extensions */			\
631 		.debug_weaknames 0 : { *(.debug_weaknames) }		\
632 		.debug_funcnames 0 : { *(.debug_funcnames) }		\
633 		.debug_typenames 0 : { *(.debug_typenames) }		\
634 		.debug_varnames  0 : { *(.debug_varnames) }		\
635 
636 		/* Stabs debugging sections.  */
637 #define STABS_DEBUG							\
638 		.stab 0 : { *(.stab) }					\
639 		.stabstr 0 : { *(.stabstr) }				\
640 		.stab.excl 0 : { *(.stab.excl) }			\
641 		.stab.exclstr 0 : { *(.stab.exclstr) }			\
642 		.stab.index 0 : { *(.stab.index) }			\
643 		.stab.indexstr 0 : { *(.stab.indexstr) }		\
644 		.comment 0 : { *(.comment) }
645 
646 #ifdef CONFIG_GENERIC_BUG
647 #define BUG_TABLE							\
648 	. = ALIGN(8);							\
649 	__bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) {		\
650 		VMLINUX_SYMBOL(__start___bug_table) = .;		\
651 		*(__bug_table)						\
652 		VMLINUX_SYMBOL(__stop___bug_table) = .;			\
653 	}
654 #else
655 #define BUG_TABLE
656 #endif
657 
658 #ifdef CONFIG_PM_TRACE
659 #define TRACEDATA							\
660 	. = ALIGN(4);							\
661 	.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {		\
662 		VMLINUX_SYMBOL(__tracedata_start) = .;			\
663 		*(.tracedata)						\
664 		VMLINUX_SYMBOL(__tracedata_end) = .;			\
665 	}
666 #else
667 #define TRACEDATA
668 #endif
669 
670 #define NOTES								\
671 	.notes : AT(ADDR(.notes) - LOAD_OFFSET) {			\
672 		VMLINUX_SYMBOL(__start_notes) = .;			\
673 		*(.note.*)						\
674 		VMLINUX_SYMBOL(__stop_notes) = .;			\
675 	}
676 
677 #define INIT_SETUP(initsetup_align)					\
678 		. = ALIGN(initsetup_align);				\
679 		VMLINUX_SYMBOL(__setup_start) = .;			\
680 		*(.init.setup)						\
681 		VMLINUX_SYMBOL(__setup_end) = .;
682 
683 #define INIT_CALLS_LEVEL(level)						\
684 		VMLINUX_SYMBOL(__initcall##level##_start) = .;		\
685 		*(.initcall##level##.init)				\
686 		*(.initcall##level##s.init)				\
687 
688 #define INIT_CALLS							\
689 		VMLINUX_SYMBOL(__initcall_start) = .;			\
690 		*(.initcallearly.init)					\
691 		INIT_CALLS_LEVEL(0)					\
692 		INIT_CALLS_LEVEL(1)					\
693 		INIT_CALLS_LEVEL(2)					\
694 		INIT_CALLS_LEVEL(3)					\
695 		INIT_CALLS_LEVEL(4)					\
696 		INIT_CALLS_LEVEL(5)					\
697 		INIT_CALLS_LEVEL(rootfs)				\
698 		INIT_CALLS_LEVEL(6)					\
699 		INIT_CALLS_LEVEL(7)					\
700 		VMLINUX_SYMBOL(__initcall_end) = .;
701 
702 #define CON_INITCALL							\
703 		VMLINUX_SYMBOL(__con_initcall_start) = .;		\
704 		*(.con_initcall.init)					\
705 		VMLINUX_SYMBOL(__con_initcall_end) = .;
706 
707 #define SECURITY_INITCALL						\
708 		VMLINUX_SYMBOL(__security_initcall_start) = .;		\
709 		*(.security_initcall.init)				\
710 		VMLINUX_SYMBOL(__security_initcall_end) = .;
711 
712 #ifdef CONFIG_BLK_DEV_INITRD
713 #define INIT_RAM_FS							\
714 	. = ALIGN(4);							\
715 	VMLINUX_SYMBOL(__initramfs_start) = .;				\
716 	*(.init.ramfs)							\
717 	. = ALIGN(8);							\
718 	*(.init.ramfs.info)
719 #else
720 #define INIT_RAM_FS
721 #endif
722 
723 /*
724  * Default discarded sections.
725  *
726  * Some archs want to discard exit text/data at runtime rather than
727  * link time due to cross-section references such as alt instructions,
728  * bug table, eh_frame, etc.  DISCARDS must be the last of output
729  * section definitions so that such archs put those in earlier section
730  * definitions.
731  */
732 #define DISCARDS							\
733 	/DISCARD/ : {							\
734 	EXIT_TEXT							\
735 	EXIT_DATA							\
736 	EXIT_CALL							\
737 	*(.discard)							\
738 	*(.discard.*)							\
739 	}
740 
741 /**
742  * PERCPU_INPUT - the percpu input sections
743  * @cacheline: cacheline size
744  *
745  * The core percpu section names and core symbols which do not rely
746  * directly upon load addresses.
747  *
748  * @cacheline is used to align subsections to avoid false cacheline
749  * sharing between subsections for different purposes.
750  */
751 #define PERCPU_INPUT(cacheline)						\
752 	VMLINUX_SYMBOL(__per_cpu_start) = .;				\
753 	*(.data..percpu..first)						\
754 	. = ALIGN(PAGE_SIZE);						\
755 	*(.data..percpu..page_aligned)					\
756 	. = ALIGN(cacheline);						\
757 	*(.data..percpu..read_mostly)					\
758 	. = ALIGN(cacheline);						\
759 	*(.data..percpu)						\
760 	*(.data..percpu..shared_aligned)				\
761 	VMLINUX_SYMBOL(__per_cpu_end) = .;
762 
763 /**
764  * PERCPU_VADDR - define output section for percpu area
765  * @cacheline: cacheline size
766  * @vaddr: explicit base address (optional)
767  * @phdr: destination PHDR (optional)
768  *
769  * Macro which expands to output section for percpu area.
770  *
771  * @cacheline is used to align subsections to avoid false cacheline
772  * sharing between subsections for different purposes.
773  *
774  * If @vaddr is not blank, it specifies explicit base address and all
775  * percpu symbols will be offset from the given address.  If blank,
776  * @vaddr always equals @laddr + LOAD_OFFSET.
777  *
778  * @phdr defines the output PHDR to use if not blank.  Be warned that
779  * output PHDR is sticky.  If @phdr is specified, the next output
780  * section in the linker script will go there too.  @phdr should have
781  * a leading colon.
782  *
783  * Note that this macros defines __per_cpu_load as an absolute symbol.
784  * If there is no need to put the percpu section at a predetermined
785  * address, use PERCPU_SECTION.
786  */
787 #define PERCPU_VADDR(cacheline, vaddr, phdr)				\
788 	VMLINUX_SYMBOL(__per_cpu_load) = .;				\
789 	.data..percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load)		\
790 				- LOAD_OFFSET) {			\
791 		PERCPU_INPUT(cacheline)					\
792 	} phdr								\
793 	. = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data..percpu);
794 
795 /**
796  * PERCPU_SECTION - define output section for percpu area, simple version
797  * @cacheline: cacheline size
798  *
799  * Align to PAGE_SIZE and outputs output section for percpu area.  This
800  * macro doesn't manipulate @vaddr or @phdr and __per_cpu_load and
801  * __per_cpu_start will be identical.
802  *
803  * This macro is equivalent to ALIGN(PAGE_SIZE); PERCPU_VADDR(@cacheline,,)
804  * except that __per_cpu_load is defined as a relative symbol against
805  * .data..percpu which is required for relocatable x86_32 configuration.
806  */
807 #define PERCPU_SECTION(cacheline)					\
808 	. = ALIGN(PAGE_SIZE);						\
809 	.data..percpu	: AT(ADDR(.data..percpu) - LOAD_OFFSET) {	\
810 		VMLINUX_SYMBOL(__per_cpu_load) = .;			\
811 		PERCPU_INPUT(cacheline)					\
812 	}
813 
814 
815 /*
816  * Definition of the high level *_SECTION macros
817  * They will fit only a subset of the architectures
818  */
819 
820 
821 /*
822  * Writeable data.
823  * All sections are combined in a single .data section.
824  * The sections following CONSTRUCTORS are arranged so their
825  * typical alignment matches.
826  * A cacheline is typical/always less than a PAGE_SIZE so
827  * the sections that has this restriction (or similar)
828  * is located before the ones requiring PAGE_SIZE alignment.
829  * NOSAVE_DATA starts and ends with a PAGE_SIZE alignment which
830  * matches the requirement of PAGE_ALIGNED_DATA.
831  *
832  * use 0 as page_align if page_aligned data is not used */
833 #define RW_DATA_SECTION(cacheline, pagealigned, inittask)		\
834 	. = ALIGN(PAGE_SIZE);						\
835 	.data : AT(ADDR(.data) - LOAD_OFFSET) {				\
836 		INIT_TASK_DATA(inittask)				\
837 		NOSAVE_DATA						\
838 		PAGE_ALIGNED_DATA(pagealigned)				\
839 		CACHELINE_ALIGNED_DATA(cacheline)			\
840 		READ_MOSTLY_DATA(cacheline)				\
841 		DATA_DATA						\
842 		CONSTRUCTORS						\
843 	}
844 
845 #define INIT_TEXT_SECTION(inittext_align)				\
846 	. = ALIGN(inittext_align);					\
847 	.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {		\
848 		VMLINUX_SYMBOL(_sinittext) = .;				\
849 		INIT_TEXT						\
850 		VMLINUX_SYMBOL(_einittext) = .;				\
851 	}
852 
853 #define INIT_DATA_SECTION(initsetup_align)				\
854 	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {		\
855 		INIT_DATA						\
856 		INIT_SETUP(initsetup_align)				\
857 		INIT_CALLS						\
858 		CON_INITCALL						\
859 		SECURITY_INITCALL					\
860 		INIT_RAM_FS						\
861 	}
862 
863 #define BSS_SECTION(sbss_align, bss_align, stop_align)			\
864 	. = ALIGN(sbss_align);						\
865 	VMLINUX_SYMBOL(__bss_start) = .;				\
866 	SBSS(sbss_align)						\
867 	BSS(bss_align)							\
868 	. = ALIGN(stop_align);						\
869 	VMLINUX_SYMBOL(__bss_stop) = .;
870