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