xref: /linux/include/asm-generic/vmlinux.lds.h (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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 #else
129 #define FTRACE_EVENTS()
130 #endif
131 
132 #ifdef CONFIG_TRACING
133 #define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;      \
134 			 *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
135 			 VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
136 #define TRACEPOINT_STR() VMLINUX_SYMBOL(__start___tracepoint_str) = .;	\
137 			 *(__tracepoint_str) /* Trace_printk fmt' pointer */ \
138 			 VMLINUX_SYMBOL(__stop___tracepoint_str) = .;
139 #else
140 #define TRACE_PRINTKS()
141 #define TRACEPOINT_STR()
142 #endif
143 
144 #ifdef CONFIG_FTRACE_SYSCALLS
145 #define TRACE_SYSCALLS() . = ALIGN(8);					\
146 			 VMLINUX_SYMBOL(__start_syscalls_metadata) = .;	\
147 			 *(__syscalls_metadata)				\
148 			 VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
149 #else
150 #define TRACE_SYSCALLS()
151 #endif
152 
153 
154 #define ___OF_TABLE(cfg, name)	_OF_TABLE_##cfg(name)
155 #define __OF_TABLE(cfg, name)	___OF_TABLE(cfg, name)
156 #define OF_TABLE(cfg, name)	__OF_TABLE(config_enabled(cfg), name)
157 #define _OF_TABLE_0(name)
158 #define _OF_TABLE_1(name)						\
159 	. = ALIGN(8);							\
160 	VMLINUX_SYMBOL(__##name##_of_table) = .;			\
161 	*(__##name##_of_table)						\
162 	*(__##name##_of_table_end)
163 
164 #define CLKSRC_OF_TABLES()	OF_TABLE(CONFIG_CLKSRC_OF, clksrc)
165 #define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip)
166 #define CLK_OF_TABLES()		OF_TABLE(CONFIG_COMMON_CLK, clk)
167 #define IOMMU_OF_TABLES()	OF_TABLE(CONFIG_OF_IOMMU, iommu)
168 #define RESERVEDMEM_OF_TABLES()	OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
169 #define CPU_METHOD_OF_TABLES()	OF_TABLE(CONFIG_SMP, cpu_method)
170 #define EARLYCON_OF_TABLES()	OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon)
171 
172 #define KERNEL_DTB()							\
173 	STRUCT_ALIGN();							\
174 	VMLINUX_SYMBOL(__dtb_start) = .;				\
175 	*(.dtb.init.rodata)						\
176 	VMLINUX_SYMBOL(__dtb_end) = .;
177 
178 /* .data section */
179 #define DATA_DATA							\
180 	*(.data)							\
181 	*(.ref.data)							\
182 	*(.data..shared_aligned) /* percpu related */			\
183 	MEM_KEEP(init.data)						\
184 	MEM_KEEP(exit.data)						\
185 	*(.data.unlikely)						\
186 	STRUCT_ALIGN();							\
187 	*(__tracepoints)						\
188 	/* implement dynamic printk debug */				\
189 	. = ALIGN(8);                                                   \
190 	VMLINUX_SYMBOL(__start___jump_table) = .;                       \
191 	*(__jump_table)                                                 \
192 	VMLINUX_SYMBOL(__stop___jump_table) = .;                        \
193 	. = ALIGN(8);							\
194 	VMLINUX_SYMBOL(__start___verbose) = .;                          \
195 	*(__verbose)                                                    \
196 	VMLINUX_SYMBOL(__stop___verbose) = .;				\
197 	LIKELY_PROFILE()		       				\
198 	BRANCH_PROFILE()						\
199 	TRACE_PRINTKS()							\
200 	TRACEPOINT_STR()
201 
202 /*
203  * Data section helpers
204  */
205 #define NOSAVE_DATA							\
206 	. = ALIGN(PAGE_SIZE);						\
207 	VMLINUX_SYMBOL(__nosave_begin) = .;				\
208 	*(.data..nosave)						\
209 	. = ALIGN(PAGE_SIZE);						\
210 	VMLINUX_SYMBOL(__nosave_end) = .;
211 
212 #define PAGE_ALIGNED_DATA(page_align)					\
213 	. = ALIGN(page_align);						\
214 	*(.data..page_aligned)
215 
216 #define READ_MOSTLY_DATA(align)						\
217 	. = ALIGN(align);						\
218 	*(.data..read_mostly)						\
219 	. = ALIGN(align);
220 
221 #define CACHELINE_ALIGNED_DATA(align)					\
222 	. = ALIGN(align);						\
223 	*(.data..cacheline_aligned)
224 
225 #define INIT_TASK_DATA(align)						\
226 	. = ALIGN(align);						\
227 	*(.data..init_task)
228 
229 /*
230  * Read only Data
231  */
232 #define RO_DATA_SECTION(align)						\
233 	. = ALIGN((align));						\
234 	.rodata           : AT(ADDR(.rodata) - LOAD_OFFSET) {		\
235 		VMLINUX_SYMBOL(__start_rodata) = .;			\
236 		*(.rodata) *(.rodata.*)					\
237 		*(__vermagic)		/* Kernel version magic */	\
238 		. = ALIGN(8);						\
239 		VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .;		\
240 		*(__tracepoints_ptrs)	/* Tracepoints: pointer array */\
241 		VMLINUX_SYMBOL(__stop___tracepoints_ptrs) = .;		\
242 		*(__tracepoints_strings)/* Tracepoints: strings */	\
243 	}								\
244 									\
245 	.rodata1          : AT(ADDR(.rodata1) - LOAD_OFFSET) {		\
246 		*(.rodata1)						\
247 	}								\
248 									\
249 	BUG_TABLE							\
250 									\
251 	/* PCI quirks */						\
252 	.pci_fixup        : AT(ADDR(.pci_fixup) - LOAD_OFFSET) {	\
253 		VMLINUX_SYMBOL(__start_pci_fixups_early) = .;		\
254 		*(.pci_fixup_early)					\
255 		VMLINUX_SYMBOL(__end_pci_fixups_early) = .;		\
256 		VMLINUX_SYMBOL(__start_pci_fixups_header) = .;		\
257 		*(.pci_fixup_header)					\
258 		VMLINUX_SYMBOL(__end_pci_fixups_header) = .;		\
259 		VMLINUX_SYMBOL(__start_pci_fixups_final) = .;		\
260 		*(.pci_fixup_final)					\
261 		VMLINUX_SYMBOL(__end_pci_fixups_final) = .;		\
262 		VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;		\
263 		*(.pci_fixup_enable)					\
264 		VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;		\
265 		VMLINUX_SYMBOL(__start_pci_fixups_resume) = .;		\
266 		*(.pci_fixup_resume)					\
267 		VMLINUX_SYMBOL(__end_pci_fixups_resume) = .;		\
268 		VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .;	\
269 		*(.pci_fixup_resume_early)				\
270 		VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .;	\
271 		VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .;		\
272 		*(.pci_fixup_suspend)					\
273 		VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .;		\
274 		VMLINUX_SYMBOL(__start_pci_fixups_suspend_late) = .;	\
275 		*(.pci_fixup_suspend_late)				\
276 		VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .;	\
277 	}								\
278 									\
279 	/* Built-in firmware blobs */					\
280 	.builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {	\
281 		VMLINUX_SYMBOL(__start_builtin_fw) = .;			\
282 		*(.builtin_fw)						\
283 		VMLINUX_SYMBOL(__end_builtin_fw) = .;			\
284 	}								\
285 									\
286 	TRACEDATA							\
287 									\
288 	/* Kernel symbol table: Normal symbols */			\
289 	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\
290 		VMLINUX_SYMBOL(__start___ksymtab) = .;			\
291 		*(SORT(___ksymtab+*))					\
292 		VMLINUX_SYMBOL(__stop___ksymtab) = .;			\
293 	}								\
294 									\
295 	/* Kernel symbol table: GPL-only symbols */			\
296 	__ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {	\
297 		VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;		\
298 		*(SORT(___ksymtab_gpl+*))				\
299 		VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;		\
300 	}								\
301 									\
302 	/* Kernel symbol table: Normal unused symbols */		\
303 	__ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {	\
304 		VMLINUX_SYMBOL(__start___ksymtab_unused) = .;		\
305 		*(SORT(___ksymtab_unused+*))				\
306 		VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;		\
307 	}								\
308 									\
309 	/* Kernel symbol table: GPL-only unused symbols */		\
310 	__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
311 		VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;	\
312 		*(SORT(___ksymtab_unused_gpl+*))			\
313 		VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;	\
314 	}								\
315 									\
316 	/* Kernel symbol table: GPL-future-only symbols */		\
317 	__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
318 		VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;	\
319 		*(SORT(___ksymtab_gpl_future+*))			\
320 		VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;	\
321 	}								\
322 									\
323 	/* Kernel symbol table: Normal symbols */			\
324 	__kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {		\
325 		VMLINUX_SYMBOL(__start___kcrctab) = .;			\
326 		*(SORT(___kcrctab+*))					\
327 		VMLINUX_SYMBOL(__stop___kcrctab) = .;			\
328 	}								\
329 									\
330 	/* Kernel symbol table: GPL-only symbols */			\
331 	__kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {	\
332 		VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;		\
333 		*(SORT(___kcrctab_gpl+*))				\
334 		VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;		\
335 	}								\
336 									\
337 	/* Kernel symbol table: Normal unused symbols */		\
338 	__kcrctab_unused  : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) {	\
339 		VMLINUX_SYMBOL(__start___kcrctab_unused) = .;		\
340 		*(SORT(___kcrctab_unused+*))				\
341 		VMLINUX_SYMBOL(__stop___kcrctab_unused) = .;		\
342 	}								\
343 									\
344 	/* Kernel symbol table: GPL-only unused symbols */		\
345 	__kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
346 		VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;	\
347 		*(SORT(___kcrctab_unused_gpl+*))			\
348 		VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;	\
349 	}								\
350 									\
351 	/* Kernel symbol table: GPL-future-only symbols */		\
352 	__kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
353 		VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;	\
354 		*(SORT(___kcrctab_gpl_future+*))			\
355 		VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;	\
356 	}								\
357 									\
358 	/* Kernel symbol table: strings */				\
359         __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) {	\
360 		*(__ksymtab_strings)					\
361 	}								\
362 									\
363 	/* __*init sections */						\
364 	__init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) {		\
365 		*(.ref.rodata)						\
366 		MEM_KEEP(init.rodata)					\
367 		MEM_KEEP(exit.rodata)					\
368 	}								\
369 									\
370 	/* Built-in module parameters. */				\
371 	__param : AT(ADDR(__param) - LOAD_OFFSET) {			\
372 		VMLINUX_SYMBOL(__start___param) = .;			\
373 		*(__param)						\
374 		VMLINUX_SYMBOL(__stop___param) = .;			\
375 	}								\
376 									\
377 	/* Built-in module versions. */					\
378 	__modver : AT(ADDR(__modver) - LOAD_OFFSET) {			\
379 		VMLINUX_SYMBOL(__start___modver) = .;			\
380 		*(__modver)						\
381 		VMLINUX_SYMBOL(__stop___modver) = .;			\
382 		. = ALIGN((align));					\
383 		VMLINUX_SYMBOL(__end_rodata) = .;			\
384 	}								\
385 	. = ALIGN((align));
386 
387 /* RODATA & RO_DATA provided for backward compatibility.
388  * All archs are supposed to use RO_DATA() */
389 #define RODATA          RO_DATA_SECTION(4096)
390 #define RO_DATA(align)  RO_DATA_SECTION(align)
391 
392 #define SECURITY_INIT							\
393 	.security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \
394 		VMLINUX_SYMBOL(__security_initcall_start) = .;		\
395 		*(.security_initcall.init) 				\
396 		VMLINUX_SYMBOL(__security_initcall_end) = .;		\
397 	}
398 
399 /* .text section. Map to function alignment to avoid address changes
400  * during second ld run in second ld pass when generating System.map */
401 #define TEXT_TEXT							\
402 		ALIGN_FUNCTION();					\
403 		*(.text.hot)						\
404 		*(.text)						\
405 		*(.ref.text)						\
406 	MEM_KEEP(init.text)						\
407 	MEM_KEEP(exit.text)						\
408 		*(.text.unlikely)
409 
410 
411 /* sched.text is aling to function alignment to secure we have same
412  * address even at second ld pass when generating System.map */
413 #define SCHED_TEXT							\
414 		ALIGN_FUNCTION();					\
415 		VMLINUX_SYMBOL(__sched_text_start) = .;			\
416 		*(.sched.text)						\
417 		VMLINUX_SYMBOL(__sched_text_end) = .;
418 
419 /* spinlock.text is aling to function alignment to secure we have same
420  * address even at second ld pass when generating System.map */
421 #define LOCK_TEXT							\
422 		ALIGN_FUNCTION();					\
423 		VMLINUX_SYMBOL(__lock_text_start) = .;			\
424 		*(.spinlock.text)					\
425 		VMLINUX_SYMBOL(__lock_text_end) = .;
426 
427 #define KPROBES_TEXT							\
428 		ALIGN_FUNCTION();					\
429 		VMLINUX_SYMBOL(__kprobes_text_start) = .;		\
430 		*(.kprobes.text)					\
431 		VMLINUX_SYMBOL(__kprobes_text_end) = .;
432 
433 #define ENTRY_TEXT							\
434 		ALIGN_FUNCTION();					\
435 		VMLINUX_SYMBOL(__entry_text_start) = .;			\
436 		*(.entry.text)						\
437 		VMLINUX_SYMBOL(__entry_text_end) = .;
438 
439 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
440 #define IRQENTRY_TEXT							\
441 		ALIGN_FUNCTION();					\
442 		VMLINUX_SYMBOL(__irqentry_text_start) = .;		\
443 		*(.irqentry.text)					\
444 		VMLINUX_SYMBOL(__irqentry_text_end) = .;
445 #else
446 #define IRQENTRY_TEXT
447 #endif
448 
449 /* Section used for early init (in .S files) */
450 #define HEAD_TEXT  *(.head.text)
451 
452 #define HEAD_TEXT_SECTION							\
453 	.head.text : AT(ADDR(.head.text) - LOAD_OFFSET) {		\
454 		HEAD_TEXT						\
455 	}
456 
457 /*
458  * Exception table
459  */
460 #define EXCEPTION_TABLE(align)						\
461 	. = ALIGN(align);						\
462 	__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {		\
463 		VMLINUX_SYMBOL(__start___ex_table) = .;			\
464 		*(__ex_table)						\
465 		VMLINUX_SYMBOL(__stop___ex_table) = .;			\
466 	}
467 
468 /*
469  * Init task
470  */
471 #define INIT_TASK_DATA_SECTION(align)					\
472 	. = ALIGN(align);						\
473 	.data..init_task :  AT(ADDR(.data..init_task) - LOAD_OFFSET) {	\
474 		INIT_TASK_DATA(align)					\
475 	}
476 
477 #ifdef CONFIG_CONSTRUCTORS
478 #define KERNEL_CTORS()	. = ALIGN(8);			   \
479 			VMLINUX_SYMBOL(__ctors_start) = .; \
480 			*(.ctors)			   \
481 			*(.init_array)			   \
482 			VMLINUX_SYMBOL(__ctors_end) = .;
483 #else
484 #define KERNEL_CTORS()
485 #endif
486 
487 /* init and exit section handling */
488 #define INIT_DATA							\
489 	*(.init.data)							\
490 	MEM_DISCARD(init.data)						\
491 	KERNEL_CTORS()							\
492 	MCOUNT_REC()							\
493 	*(.init.rodata)							\
494 	FTRACE_EVENTS()							\
495 	TRACE_SYSCALLS()						\
496 	KPROBE_BLACKLIST()						\
497 	MEM_DISCARD(init.rodata)					\
498 	CLK_OF_TABLES()							\
499 	RESERVEDMEM_OF_TABLES()						\
500 	CLKSRC_OF_TABLES()						\
501 	IOMMU_OF_TABLES()						\
502 	CPU_METHOD_OF_TABLES()						\
503 	KERNEL_DTB()							\
504 	IRQCHIP_OF_MATCH_TABLE()					\
505 	EARLYCON_OF_TABLES()
506 
507 #define INIT_TEXT							\
508 	*(.init.text)							\
509 	MEM_DISCARD(init.text)
510 
511 #define EXIT_DATA							\
512 	*(.exit.data)							\
513 	MEM_DISCARD(exit.data)						\
514 	MEM_DISCARD(exit.rodata)
515 
516 #define EXIT_TEXT							\
517 	*(.exit.text)							\
518 	MEM_DISCARD(exit.text)
519 
520 #define EXIT_CALL							\
521 	*(.exitcall.exit)
522 
523 /*
524  * bss (Block Started by Symbol) - uninitialized data
525  * zeroed during startup
526  */
527 #define SBSS(sbss_align)						\
528 	. = ALIGN(sbss_align);						\
529 	.sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {				\
530 		*(.sbss)						\
531 		*(.scommon)						\
532 	}
533 
534 /*
535  * Allow archectures to redefine BSS_FIRST_SECTIONS to add extra
536  * sections to the front of bss.
537  */
538 #ifndef BSS_FIRST_SECTIONS
539 #define BSS_FIRST_SECTIONS
540 #endif
541 
542 #define BSS(bss_align)							\
543 	. = ALIGN(bss_align);						\
544 	.bss : AT(ADDR(.bss) - LOAD_OFFSET) {				\
545 		BSS_FIRST_SECTIONS					\
546 		*(.bss..page_aligned)					\
547 		*(.dynbss)						\
548 		*(.bss)							\
549 		*(COMMON)						\
550 	}
551 
552 /*
553  * DWARF debug sections.
554  * Symbols in the DWARF debugging sections are relative to
555  * the beginning of the section so we begin them at 0.
556  */
557 #define DWARF_DEBUG							\
558 		/* DWARF 1 */						\
559 		.debug          0 : { *(.debug) }			\
560 		.line           0 : { *(.line) }			\
561 		/* GNU DWARF 1 extensions */				\
562 		.debug_srcinfo  0 : { *(.debug_srcinfo) }		\
563 		.debug_sfnames  0 : { *(.debug_sfnames) }		\
564 		/* DWARF 1.1 and DWARF 2 */				\
565 		.debug_aranges  0 : { *(.debug_aranges) }		\
566 		.debug_pubnames 0 : { *(.debug_pubnames) }		\
567 		/* DWARF 2 */						\
568 		.debug_info     0 : { *(.debug_info			\
569 				.gnu.linkonce.wi.*) }			\
570 		.debug_abbrev   0 : { *(.debug_abbrev) }		\
571 		.debug_line     0 : { *(.debug_line) }			\
572 		.debug_frame    0 : { *(.debug_frame) }			\
573 		.debug_str      0 : { *(.debug_str) }			\
574 		.debug_loc      0 : { *(.debug_loc) }			\
575 		.debug_macinfo  0 : { *(.debug_macinfo) }		\
576 		/* SGI/MIPS DWARF 2 extensions */			\
577 		.debug_weaknames 0 : { *(.debug_weaknames) }		\
578 		.debug_funcnames 0 : { *(.debug_funcnames) }		\
579 		.debug_typenames 0 : { *(.debug_typenames) }		\
580 		.debug_varnames  0 : { *(.debug_varnames) }		\
581 
582 		/* Stabs debugging sections.  */
583 #define STABS_DEBUG							\
584 		.stab 0 : { *(.stab) }					\
585 		.stabstr 0 : { *(.stabstr) }				\
586 		.stab.excl 0 : { *(.stab.excl) }			\
587 		.stab.exclstr 0 : { *(.stab.exclstr) }			\
588 		.stab.index 0 : { *(.stab.index) }			\
589 		.stab.indexstr 0 : { *(.stab.indexstr) }		\
590 		.comment 0 : { *(.comment) }
591 
592 #ifdef CONFIG_GENERIC_BUG
593 #define BUG_TABLE							\
594 	. = ALIGN(8);							\
595 	__bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) {		\
596 		VMLINUX_SYMBOL(__start___bug_table) = .;		\
597 		*(__bug_table)						\
598 		VMLINUX_SYMBOL(__stop___bug_table) = .;			\
599 	}
600 #else
601 #define BUG_TABLE
602 #endif
603 
604 #ifdef CONFIG_PM_TRACE
605 #define TRACEDATA							\
606 	. = ALIGN(4);							\
607 	.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {		\
608 		VMLINUX_SYMBOL(__tracedata_start) = .;			\
609 		*(.tracedata)						\
610 		VMLINUX_SYMBOL(__tracedata_end) = .;			\
611 	}
612 #else
613 #define TRACEDATA
614 #endif
615 
616 #define NOTES								\
617 	.notes : AT(ADDR(.notes) - LOAD_OFFSET) {			\
618 		VMLINUX_SYMBOL(__start_notes) = .;			\
619 		*(.note.*)						\
620 		VMLINUX_SYMBOL(__stop_notes) = .;			\
621 	}
622 
623 #define INIT_SETUP(initsetup_align)					\
624 		. = ALIGN(initsetup_align);				\
625 		VMLINUX_SYMBOL(__setup_start) = .;			\
626 		*(.init.setup)						\
627 		VMLINUX_SYMBOL(__setup_end) = .;
628 
629 #define INIT_CALLS_LEVEL(level)						\
630 		VMLINUX_SYMBOL(__initcall##level##_start) = .;		\
631 		*(.initcall##level##.init)				\
632 		*(.initcall##level##s.init)				\
633 
634 #define INIT_CALLS							\
635 		VMLINUX_SYMBOL(__initcall_start) = .;			\
636 		*(.initcallearly.init)					\
637 		INIT_CALLS_LEVEL(0)					\
638 		INIT_CALLS_LEVEL(1)					\
639 		INIT_CALLS_LEVEL(2)					\
640 		INIT_CALLS_LEVEL(3)					\
641 		INIT_CALLS_LEVEL(4)					\
642 		INIT_CALLS_LEVEL(5)					\
643 		INIT_CALLS_LEVEL(rootfs)				\
644 		INIT_CALLS_LEVEL(6)					\
645 		INIT_CALLS_LEVEL(7)					\
646 		VMLINUX_SYMBOL(__initcall_end) = .;
647 
648 #define CON_INITCALL							\
649 		VMLINUX_SYMBOL(__con_initcall_start) = .;		\
650 		*(.con_initcall.init)					\
651 		VMLINUX_SYMBOL(__con_initcall_end) = .;
652 
653 #define SECURITY_INITCALL						\
654 		VMLINUX_SYMBOL(__security_initcall_start) = .;		\
655 		*(.security_initcall.init)				\
656 		VMLINUX_SYMBOL(__security_initcall_end) = .;
657 
658 #ifdef CONFIG_BLK_DEV_INITRD
659 #define INIT_RAM_FS							\
660 	. = ALIGN(4);							\
661 	VMLINUX_SYMBOL(__initramfs_start) = .;				\
662 	*(.init.ramfs)							\
663 	. = ALIGN(8);							\
664 	*(.init.ramfs.info)
665 #else
666 #define INIT_RAM_FS
667 #endif
668 
669 /*
670  * Default discarded sections.
671  *
672  * Some archs want to discard exit text/data at runtime rather than
673  * link time due to cross-section references such as alt instructions,
674  * bug table, eh_frame, etc.  DISCARDS must be the last of output
675  * section definitions so that such archs put those in earlier section
676  * definitions.
677  */
678 #define DISCARDS							\
679 	/DISCARD/ : {							\
680 	EXIT_TEXT							\
681 	EXIT_DATA							\
682 	EXIT_CALL							\
683 	*(.discard)							\
684 	*(.discard.*)							\
685 	}
686 
687 /**
688  * PERCPU_INPUT - the percpu input sections
689  * @cacheline: cacheline size
690  *
691  * The core percpu section names and core symbols which do not rely
692  * directly upon load addresses.
693  *
694  * @cacheline is used to align subsections to avoid false cacheline
695  * sharing between subsections for different purposes.
696  */
697 #define PERCPU_INPUT(cacheline)						\
698 	VMLINUX_SYMBOL(__per_cpu_start) = .;				\
699 	*(.data..percpu..first)						\
700 	. = ALIGN(PAGE_SIZE);						\
701 	*(.data..percpu..page_aligned)					\
702 	. = ALIGN(cacheline);						\
703 	*(.data..percpu..read_mostly)					\
704 	. = ALIGN(cacheline);						\
705 	*(.data..percpu)						\
706 	*(.data..percpu..shared_aligned)				\
707 	VMLINUX_SYMBOL(__per_cpu_end) = .;
708 
709 /**
710  * PERCPU_VADDR - define output section for percpu area
711  * @cacheline: cacheline size
712  * @vaddr: explicit base address (optional)
713  * @phdr: destination PHDR (optional)
714  *
715  * Macro which expands to output section for percpu area.
716  *
717  * @cacheline is used to align subsections to avoid false cacheline
718  * sharing between subsections for different purposes.
719  *
720  * If @vaddr is not blank, it specifies explicit base address and all
721  * percpu symbols will be offset from the given address.  If blank,
722  * @vaddr always equals @laddr + LOAD_OFFSET.
723  *
724  * @phdr defines the output PHDR to use if not blank.  Be warned that
725  * output PHDR is sticky.  If @phdr is specified, the next output
726  * section in the linker script will go there too.  @phdr should have
727  * a leading colon.
728  *
729  * Note that this macros defines __per_cpu_load as an absolute symbol.
730  * If there is no need to put the percpu section at a predetermined
731  * address, use PERCPU_SECTION.
732  */
733 #define PERCPU_VADDR(cacheline, vaddr, phdr)				\
734 	VMLINUX_SYMBOL(__per_cpu_load) = .;				\
735 	.data..percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load)		\
736 				- LOAD_OFFSET) {			\
737 		PERCPU_INPUT(cacheline)					\
738 	} phdr								\
739 	. = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data..percpu);
740 
741 /**
742  * PERCPU_SECTION - define output section for percpu area, simple version
743  * @cacheline: cacheline size
744  *
745  * Align to PAGE_SIZE and outputs output section for percpu area.  This
746  * macro doesn't manipulate @vaddr or @phdr and __per_cpu_load and
747  * __per_cpu_start will be identical.
748  *
749  * This macro is equivalent to ALIGN(PAGE_SIZE); PERCPU_VADDR(@cacheline,,)
750  * except that __per_cpu_load is defined as a relative symbol against
751  * .data..percpu which is required for relocatable x86_32 configuration.
752  */
753 #define PERCPU_SECTION(cacheline)					\
754 	. = ALIGN(PAGE_SIZE);						\
755 	.data..percpu	: AT(ADDR(.data..percpu) - LOAD_OFFSET) {	\
756 		VMLINUX_SYMBOL(__per_cpu_load) = .;			\
757 		PERCPU_INPUT(cacheline)					\
758 	}
759 
760 
761 /*
762  * Definition of the high level *_SECTION macros
763  * They will fit only a subset of the architectures
764  */
765 
766 
767 /*
768  * Writeable data.
769  * All sections are combined in a single .data section.
770  * The sections following CONSTRUCTORS are arranged so their
771  * typical alignment matches.
772  * A cacheline is typical/always less than a PAGE_SIZE so
773  * the sections that has this restriction (or similar)
774  * is located before the ones requiring PAGE_SIZE alignment.
775  * NOSAVE_DATA starts and ends with a PAGE_SIZE alignment which
776  * matches the requirement of PAGE_ALIGNED_DATA.
777  *
778  * use 0 as page_align if page_aligned data is not used */
779 #define RW_DATA_SECTION(cacheline, pagealigned, inittask)		\
780 	. = ALIGN(PAGE_SIZE);						\
781 	.data : AT(ADDR(.data) - LOAD_OFFSET) {				\
782 		INIT_TASK_DATA(inittask)				\
783 		NOSAVE_DATA						\
784 		PAGE_ALIGNED_DATA(pagealigned)				\
785 		CACHELINE_ALIGNED_DATA(cacheline)			\
786 		READ_MOSTLY_DATA(cacheline)				\
787 		DATA_DATA						\
788 		CONSTRUCTORS						\
789 	}
790 
791 #define INIT_TEXT_SECTION(inittext_align)				\
792 	. = ALIGN(inittext_align);					\
793 	.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {		\
794 		VMLINUX_SYMBOL(_sinittext) = .;				\
795 		INIT_TEXT						\
796 		VMLINUX_SYMBOL(_einittext) = .;				\
797 	}
798 
799 #define INIT_DATA_SECTION(initsetup_align)				\
800 	.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {		\
801 		INIT_DATA						\
802 		INIT_SETUP(initsetup_align)				\
803 		INIT_CALLS						\
804 		CON_INITCALL						\
805 		SECURITY_INITCALL					\
806 		INIT_RAM_FS						\
807 	}
808 
809 #define BSS_SECTION(sbss_align, bss_align, stop_align)			\
810 	. = ALIGN(sbss_align);						\
811 	VMLINUX_SYMBOL(__bss_start) = .;				\
812 	SBSS(sbss_align)						\
813 	BSS(bss_align)							\
814 	. = ALIGN(stop_align);						\
815 	VMLINUX_SYMBOL(__bss_stop) = .;
816