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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * ld script for the x86 kernel
4 *
5 * Historic 32-bit version written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
6 *
7 * Modernisation, unification and other changes and fixes:
8 *   Copyright (C) 2007-2009  Sam Ravnborg <sam@ravnborg.org>
9 *
10 *
11 * Don't define absolute symbols until and unless you know that symbol
12 * value is should remain constant even if kernel image is relocated
13 * at run time. Absolute symbols are not relocated. If symbol value should
14 * change if kernel is relocated, make the symbol section relative and
15 * put it inside the section definition.
16 */
17
18#ifdef CONFIG_X86_32
19#define LOAD_OFFSET __PAGE_OFFSET
20#else
21#define LOAD_OFFSET __START_KERNEL_map
22#endif
23
24#include <asm-generic/vmlinux.lds.h>
25#include <asm/asm-offsets.h>
26#include <asm/thread_info.h>
27#include <asm/page_types.h>
28#include <asm/orc_lookup.h>
29#include <asm/cache.h>
30#include <asm/boot.h>
31
32#undef i386     /* in case the preprocessor is a 32bit one */
33
34OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT)
35
36#ifdef CONFIG_X86_32
37OUTPUT_ARCH(i386)
38ENTRY(phys_startup_32)
39jiffies = jiffies_64;
40#else
41OUTPUT_ARCH(i386:x86-64)
42ENTRY(phys_startup_64)
43jiffies_64 = jiffies;
44#endif
45
46#if defined(CONFIG_X86_64)
47/*
48 * On 64-bit, align RODATA to 2MB so we retain large page mappings for
49 * boundaries spanning kernel text, rodata and data sections.
50 *
51 * However, kernel identity mappings will have different RWX permissions
52 * to the pages mapping to text and to the pages padding (which are freed) the
53 * text section. Hence kernel identity mappings will be broken to smaller
54 * pages. For 64-bit, kernel text and kernel identity mappings are different,
55 * so we can enable protection checks as well as retain 2MB large page
56 * mappings for kernel text.
57 */
58#define X64_ALIGN_RODATA_BEGIN	. = ALIGN(HPAGE_SIZE);
59
60#define X64_ALIGN_RODATA_END					\
61		. = ALIGN(HPAGE_SIZE);				\
62		__end_rodata_hpage_align = .;
63
64#define ALIGN_ENTRY_TEXT_BEGIN	. = ALIGN(PMD_SIZE);
65#define ALIGN_ENTRY_TEXT_END	. = ALIGN(PMD_SIZE);
66
67#else
68
69#define X64_ALIGN_RODATA_BEGIN
70#define X64_ALIGN_RODATA_END
71
72#define ALIGN_ENTRY_TEXT_BEGIN
73#define ALIGN_ENTRY_TEXT_END
74
75#endif
76
77PHDRS {
78	text PT_LOAD FLAGS(5);          /* R_E */
79	data PT_LOAD FLAGS(6);          /* RW_ */
80#ifdef CONFIG_X86_64
81#ifdef CONFIG_SMP
82	percpu PT_LOAD FLAGS(6);        /* RW_ */
83#endif
84	init PT_LOAD FLAGS(7);          /* RWE */
85#endif
86	note PT_NOTE FLAGS(0);          /* ___ */
87}
88
89SECTIONS
90{
91#ifdef CONFIG_X86_32
92	. = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
93	phys_startup_32 = ABSOLUTE(startup_32 - LOAD_OFFSET);
94#else
95	. = __START_KERNEL;
96	phys_startup_64 = ABSOLUTE(startup_64 - LOAD_OFFSET);
97#endif
98
99	/* Text and read-only data */
100	.text :  AT(ADDR(.text) - LOAD_OFFSET) {
101		_text = .;
102		_stext = .;
103		/* bootstrapping code */
104		HEAD_TEXT
105		. = ALIGN(8);
106		TEXT_TEXT
107		SCHED_TEXT
108		CPUIDLE_TEXT
109		LOCK_TEXT
110		KPROBES_TEXT
111		ALIGN_ENTRY_TEXT_BEGIN
112		ENTRY_TEXT
113		IRQENTRY_TEXT
114		ALIGN_ENTRY_TEXT_END
115		SOFTIRQENTRY_TEXT
116		*(.fixup)
117		*(.gnu.warning)
118
119#ifdef CONFIG_X86_64
120		. = ALIGN(PAGE_SIZE);
121		VMLINUX_SYMBOL(__entry_trampoline_start) = .;
122		_entry_trampoline = .;
123		*(.entry_trampoline)
124		. = ALIGN(PAGE_SIZE);
125		VMLINUX_SYMBOL(__entry_trampoline_end) = .;
126		ASSERT(. - _entry_trampoline == PAGE_SIZE, "entry trampoline is too big");
127#endif
128
129#ifdef CONFIG_RETPOLINE
130		__indirect_thunk_start = .;
131		*(.text.__x86.indirect_thunk)
132		__indirect_thunk_end = .;
133#endif
134
135		/* End of text section */
136		_etext = .;
137	} :text = 0x9090
138
139	NOTES :text :note
140
141	EXCEPTION_TABLE(16) :text = 0x9090
142
143	/* .text should occupy whole number of pages */
144	. = ALIGN(PAGE_SIZE);
145	X64_ALIGN_RODATA_BEGIN
146	RO_DATA(PAGE_SIZE)
147	X64_ALIGN_RODATA_END
148
149	/* Data */
150	.data : AT(ADDR(.data) - LOAD_OFFSET) {
151		/* Start of data section */
152		_sdata = .;
153
154		/* init_task */
155		INIT_TASK_DATA(THREAD_SIZE)
156
157#ifdef CONFIG_X86_32
158		/* 32 bit has nosave before _edata */
159		NOSAVE_DATA
160#endif
161
162		PAGE_ALIGNED_DATA(PAGE_SIZE)
163
164		CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
165
166		DATA_DATA
167		CONSTRUCTORS
168
169		/* rarely changed data like cpu maps */
170		READ_MOSTLY_DATA(INTERNODE_CACHE_BYTES)
171
172		/* End of data section */
173		_edata = .;
174	} :data
175
176	BUG_TABLE
177
178	ORC_UNWIND_TABLE
179
180	. = ALIGN(PAGE_SIZE);
181	__vvar_page = .;
182
183	.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
184		/* work around gold bug 13023 */
185		__vvar_beginning_hack = .;
186
187		/* Place all vvars at the offsets in asm/vvar.h. */
188#define EMIT_VVAR(name, offset) 			\
189		. = __vvar_beginning_hack + offset;	\
190		*(.vvar_ ## name)
191#define __VVAR_KERNEL_LDS
192#include <asm/vvar.h>
193#undef __VVAR_KERNEL_LDS
194#undef EMIT_VVAR
195
196		/*
197		 * Pad the rest of the page with zeros.  Otherwise the loader
198		 * can leave garbage here.
199		 */
200		. = __vvar_beginning_hack + PAGE_SIZE;
201	} :data
202
203       . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
204
205	/* Init code and data - will be freed after init */
206	. = ALIGN(PAGE_SIZE);
207	.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
208		__init_begin = .; /* paired with __init_end */
209	}
210
211#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
212	/*
213	 * percpu offsets are zero-based on SMP.  PERCPU_VADDR() changes the
214	 * output PHDR, so the next output section - .init.text - should
215	 * start another segment - init.
216	 */
217	PERCPU_VADDR(INTERNODE_CACHE_BYTES, 0, :percpu)
218	ASSERT(SIZEOF(.data..percpu) < CONFIG_PHYSICAL_START,
219	       "per-CPU data too large - increase CONFIG_PHYSICAL_START")
220#endif
221
222	INIT_TEXT_SECTION(PAGE_SIZE)
223#ifdef CONFIG_X86_64
224	:init
225#endif
226
227	/*
228	 * Section for code used exclusively before alternatives are run. All
229	 * references to such code must be patched out by alternatives, normally
230	 * by using X86_FEATURE_ALWAYS CPU feature bit.
231	 *
232	 * See static_cpu_has() for an example.
233	 */
234	.altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) {
235		*(.altinstr_aux)
236	}
237
238	INIT_DATA_SECTION(16)
239
240	.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
241		__x86_cpu_dev_start = .;
242		*(.x86_cpu_dev.init)
243		__x86_cpu_dev_end = .;
244	}
245
246#ifdef CONFIG_X86_INTEL_MID
247	.x86_intel_mid_dev.init : AT(ADDR(.x86_intel_mid_dev.init) - \
248								LOAD_OFFSET) {
249		__x86_intel_mid_dev_start = .;
250		*(.x86_intel_mid_dev.init)
251		__x86_intel_mid_dev_end = .;
252	}
253#endif
254
255	/*
256	 * start address and size of operations which during runtime
257	 * can be patched with virtualization friendly instructions or
258	 * baremetal native ones. Think page table operations.
259	 * Details in paravirt_types.h
260	 */
261	. = ALIGN(8);
262	.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
263		__parainstructions = .;
264		*(.parainstructions)
265		__parainstructions_end = .;
266	}
267
268	/*
269	 * struct alt_inst entries. From the header (alternative.h):
270	 * "Alternative instructions for different CPU types or capabilities"
271	 * Think locking instructions on spinlocks.
272	 */
273	. = ALIGN(8);
274	.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
275		__alt_instructions = .;
276		*(.altinstructions)
277		__alt_instructions_end = .;
278	}
279
280	/*
281	 * And here are the replacement instructions. The linker sticks
282	 * them as binary blobs. The .altinstructions has enough data to
283	 * get the address and the length of them to patch the kernel safely.
284	 */
285	.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
286		*(.altinstr_replacement)
287	}
288
289	/*
290	 * struct iommu_table_entry entries are injected in this section.
291	 * It is an array of IOMMUs which during run time gets sorted depending
292	 * on its dependency order. After rootfs_initcall is complete
293	 * this section can be safely removed.
294	 */
295	.iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) {
296		__iommu_table = .;
297		*(.iommu_table)
298		__iommu_table_end = .;
299	}
300
301	. = ALIGN(8);
302	.apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) {
303		__apicdrivers = .;
304		*(.apicdrivers);
305		__apicdrivers_end = .;
306	}
307
308	. = ALIGN(8);
309	/*
310	 * .exit.text is discard at runtime, not link time, to deal with
311	 *  references from .altinstructions and .eh_frame
312	 */
313	.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) {
314		EXIT_TEXT
315	}
316
317	.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
318		EXIT_DATA
319	}
320
321#if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
322	PERCPU_SECTION(INTERNODE_CACHE_BYTES)
323#endif
324
325	. = ALIGN(PAGE_SIZE);
326
327	/* freed after init ends here */
328	.init.end : AT(ADDR(.init.end) - LOAD_OFFSET) {
329		__init_end = .;
330	}
331
332	/*
333	 * smp_locks might be freed after init
334	 * start/end must be page aligned
335	 */
336	. = ALIGN(PAGE_SIZE);
337	.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
338		__smp_locks = .;
339		*(.smp_locks)
340		. = ALIGN(PAGE_SIZE);
341		__smp_locks_end = .;
342	}
343
344#ifdef CONFIG_X86_64
345	.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
346		NOSAVE_DATA
347	}
348#endif
349
350	/* BSS */
351	. = ALIGN(PAGE_SIZE);
352	.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
353		__bss_start = .;
354		*(.bss..page_aligned)
355		*(.bss)
356		. = ALIGN(PAGE_SIZE);
357		__bss_stop = .;
358	}
359
360	. = ALIGN(PAGE_SIZE);
361	.brk : AT(ADDR(.brk) - LOAD_OFFSET) {
362		__brk_base = .;
363		. += 64 * 1024;		/* 64k alignment slop space */
364		*(.brk_reservation)	/* areas brk users have reserved */
365		__brk_limit = .;
366	}
367
368	. = ALIGN(PAGE_SIZE);		/* keep VO_INIT_SIZE page aligned */
369	_end = .;
370
371        STABS_DEBUG
372        DWARF_DEBUG
373
374	/* Sections to be discarded */
375	DISCARDS
376	/DISCARD/ : {
377		*(.eh_frame)
378	}
379}
380
381
382#ifdef CONFIG_X86_32
383/*
384 * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
385 */
386. = ASSERT((_end - LOAD_OFFSET <= KERNEL_IMAGE_SIZE),
387	   "kernel image bigger than KERNEL_IMAGE_SIZE");
388#else
389/*
390 * Per-cpu symbols which need to be offset from __per_cpu_load
391 * for the boot processor.
392 */
393#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x) + __per_cpu_load
394INIT_PER_CPU(gdt_page);
395INIT_PER_CPU(irq_stack_union);
396
397/*
398 * Build-time check on the image size:
399 */
400. = ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
401	   "kernel image bigger than KERNEL_IMAGE_SIZE");
402
403#ifdef CONFIG_SMP
404. = ASSERT((irq_stack_union == 0),
405           "irq_stack_union is not at start of per-cpu area");
406#endif
407
408#endif /* CONFIG_X86_32 */
409
410#ifdef CONFIG_KEXEC_CORE
411#include <asm/kexec.h>
412
413. = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
414           "kexec control code size is too big");
415#endif
416
417