xref: /openbmc/linux/arch/arm64/kernel/vmlinux.lds.S (revision aaa746ad)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * ld script to make ARM Linux kernel
4 * taken from the i386 version by Russell King
5 * Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
6 */
7
8#include <asm/hyp_image.h>
9#ifdef CONFIG_KVM
10#define HYPERVISOR_EXTABLE					\
11	. = ALIGN(SZ_8);					\
12	__start___kvm_ex_table = .;				\
13	*(__kvm_ex_table)					\
14	__stop___kvm_ex_table = .;
15
16#define HYPERVISOR_DATA_SECTIONS				\
17	HYP_SECTION_NAME(.rodata) : {				\
18		. = ALIGN(PAGE_SIZE);				\
19		__hyp_rodata_start = .;				\
20		*(HYP_SECTION_NAME(.data..ro_after_init))	\
21		*(HYP_SECTION_NAME(.rodata))			\
22		. = ALIGN(PAGE_SIZE);				\
23		__hyp_rodata_end = .;				\
24	}
25
26#define HYPERVISOR_PERCPU_SECTION				\
27	. = ALIGN(PAGE_SIZE);					\
28	HYP_SECTION_NAME(.data..percpu) : {			\
29		*(HYP_SECTION_NAME(.data..percpu))		\
30	}
31
32#define HYPERVISOR_RELOC_SECTION				\
33	.hyp.reloc : ALIGN(4) {					\
34		__hyp_reloc_begin = .;				\
35		*(.hyp.reloc)					\
36		__hyp_reloc_end = .;				\
37	}
38
39#define BSS_FIRST_SECTIONS					\
40	__hyp_bss_start = .;					\
41	*(HYP_SECTION_NAME(.bss))				\
42	. = ALIGN(PAGE_SIZE);					\
43	__hyp_bss_end = .;
44
45/*
46 * We require that __hyp_bss_start and __bss_start are aligned, and enforce it
47 * with an assertion. But the BSS_SECTION macro places an empty .sbss section
48 * between them, which can in some cases cause the linker to misalign them. To
49 * work around the issue, force a page alignment for __bss_start.
50 */
51#define SBSS_ALIGN			PAGE_SIZE
52#else /* CONFIG_KVM */
53#define HYPERVISOR_EXTABLE
54#define HYPERVISOR_DATA_SECTIONS
55#define HYPERVISOR_PERCPU_SECTION
56#define HYPERVISOR_RELOC_SECTION
57#define SBSS_ALIGN			0
58#endif
59
60#define RO_EXCEPTION_TABLE_ALIGN	4
61#define RUNTIME_DISCARD_EXIT
62
63#include <asm-generic/vmlinux.lds.h>
64#include <asm/cache.h>
65#include <asm/kernel-pgtable.h>
66#include <asm/kexec.h>
67#include <asm/memory.h>
68#include <asm/page.h>
69
70#include "image.h"
71
72OUTPUT_ARCH(aarch64)
73ENTRY(_text)
74
75jiffies = jiffies_64;
76
77#define HYPERVISOR_TEXT					\
78	. = ALIGN(PAGE_SIZE);				\
79	__hyp_idmap_text_start = .;			\
80	*(.hyp.idmap.text)				\
81	__hyp_idmap_text_end = .;			\
82	__hyp_text_start = .;				\
83	*(.hyp.text)					\
84	HYPERVISOR_EXTABLE				\
85	. = ALIGN(PAGE_SIZE);				\
86	__hyp_text_end = .;
87
88#define IDMAP_TEXT					\
89	. = ALIGN(SZ_4K);				\
90	__idmap_text_start = .;				\
91	*(.idmap.text)					\
92	__idmap_text_end = .;
93
94#ifdef CONFIG_HIBERNATION
95#define HIBERNATE_TEXT					\
96	__hibernate_exit_text_start = .;		\
97	*(.hibernate_exit.text)				\
98	__hibernate_exit_text_end = .;
99#else
100#define HIBERNATE_TEXT
101#endif
102
103#ifdef CONFIG_KEXEC_CORE
104#define KEXEC_TEXT					\
105	__relocate_new_kernel_start = .;		\
106	*(.kexec_relocate.text)				\
107	__relocate_new_kernel_end = .;
108#else
109#define KEXEC_TEXT
110#endif
111
112#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
113#define TRAMP_TEXT					\
114	. = ALIGN(PAGE_SIZE);				\
115	__entry_tramp_text_start = .;			\
116	*(.entry.tramp.text)				\
117	. = ALIGN(PAGE_SIZE);				\
118	__entry_tramp_text_end = .;			\
119	*(.entry.tramp.rodata)
120#else
121#define TRAMP_TEXT
122#endif
123
124#ifdef CONFIG_UNWIND_TABLES
125#define UNWIND_DATA_SECTIONS				\
126	.eh_frame : {					\
127		__eh_frame_start = .;			\
128		*(.eh_frame)				\
129		__eh_frame_end = .;			\
130	}
131#else
132#define UNWIND_DATA_SECTIONS
133#endif
134
135/*
136 * The size of the PE/COFF section that covers the kernel image, which
137 * runs from _stext to _edata, must be a round multiple of the PE/COFF
138 * FileAlignment, which we set to its minimum value of 0x200. '_stext'
139 * itself is 4 KB aligned, so padding out _edata to a 0x200 aligned
140 * boundary should be sufficient.
141 */
142PECOFF_FILE_ALIGNMENT = 0x200;
143
144#ifdef CONFIG_EFI
145#define PECOFF_EDATA_PADDING	\
146	.pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
147#else
148#define PECOFF_EDATA_PADDING
149#endif
150
151SECTIONS
152{
153	/*
154	 * XXX: The linker does not define how output sections are
155	 * assigned to input sections when there are multiple statements
156	 * matching the same input section name.  There is no documented
157	 * order of matching.
158	 */
159	DISCARDS
160	/DISCARD/ : {
161		*(.interp .dynamic)
162		*(.dynsym .dynstr .hash .gnu.hash)
163	}
164
165	. = KIMAGE_VADDR;
166
167	.head.text : {
168		_text = .;
169		HEAD_TEXT
170	}
171	.text : ALIGN(SEGMENT_ALIGN) {	/* Real text segment		*/
172		_stext = .;		/* Text and read-only data	*/
173			IRQENTRY_TEXT
174			SOFTIRQENTRY_TEXT
175			ENTRY_TEXT
176			TEXT_TEXT
177			SCHED_TEXT
178			CPUIDLE_TEXT
179			LOCK_TEXT
180			KPROBES_TEXT
181			HYPERVISOR_TEXT
182			IDMAP_TEXT
183			*(.gnu.warning)
184		. = ALIGN(16);
185		*(.got)			/* Global offset table		*/
186	}
187
188	/*
189	 * Make sure that the .got.plt is either completely empty or it
190	 * contains only the lazy dispatch entries.
191	 */
192	.got.plt : { *(.got.plt) }
193	ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18,
194	       "Unexpected GOT/PLT entries detected!")
195
196	. = ALIGN(SEGMENT_ALIGN);
197	_etext = .;			/* End of text section */
198
199	/* everything from this point to __init_begin will be marked RO NX */
200	RO_DATA(PAGE_SIZE)
201
202	HYPERVISOR_DATA_SECTIONS
203
204	/* code sections that are never executed via the kernel mapping */
205	.rodata.text : {
206		TRAMP_TEXT
207		HIBERNATE_TEXT
208		KEXEC_TEXT
209		. = ALIGN(PAGE_SIZE);
210	}
211
212	idmap_pg_dir = .;
213	. += PAGE_SIZE;
214
215#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
216	tramp_pg_dir = .;
217	. += PAGE_SIZE;
218#endif
219
220	reserved_pg_dir = .;
221	. += PAGE_SIZE;
222
223	swapper_pg_dir = .;
224	. += PAGE_SIZE;
225
226	. = ALIGN(SEGMENT_ALIGN);
227	__init_begin = .;
228	__inittext_begin = .;
229
230	INIT_TEXT_SECTION(8)
231
232	__exittext_begin = .;
233	.exit.text : {
234		EXIT_TEXT
235	}
236	__exittext_end = .;
237
238	. = ALIGN(4);
239	.altinstructions : {
240		__alt_instructions = .;
241		*(.altinstructions)
242		__alt_instructions_end = .;
243	}
244
245	UNWIND_DATA_SECTIONS
246
247	. = ALIGN(SEGMENT_ALIGN);
248	__inittext_end = .;
249	__initdata_begin = .;
250
251	init_idmap_pg_dir = .;
252	. += INIT_IDMAP_DIR_SIZE;
253	init_idmap_pg_end = .;
254
255	.init.data : {
256		INIT_DATA
257		INIT_SETUP(16)
258		INIT_CALLS
259		CON_INITCALL
260		INIT_RAM_FS
261		*(.init.altinstructions .init.bss)	/* from the EFI stub */
262	}
263	.exit.data : {
264		EXIT_DATA
265	}
266
267	PERCPU_SECTION(L1_CACHE_BYTES)
268	HYPERVISOR_PERCPU_SECTION
269
270	HYPERVISOR_RELOC_SECTION
271
272	.rela.dyn : ALIGN(8) {
273		__rela_start = .;
274		*(.rela .rela*)
275		__rela_end = .;
276	}
277
278	.relr.dyn : ALIGN(8) {
279		__relr_start = .;
280		*(.relr.dyn)
281		__relr_end = .;
282	}
283
284	. = ALIGN(SEGMENT_ALIGN);
285	__initdata_end = .;
286	__init_end = .;
287
288	_data = .;
289	_sdata = .;
290	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN)
291
292	/*
293	 * Data written with the MMU off but read with the MMU on requires
294	 * cache lines to be invalidated, discarding up to a Cache Writeback
295	 * Granule (CWG) of data from the cache. Keep the section that
296	 * requires this type of maintenance to be in its own Cache Writeback
297	 * Granule (CWG) area so the cache maintenance operations don't
298	 * interfere with adjacent data.
299	 */
300	.mmuoff.data.write : ALIGN(SZ_2K) {
301		__mmuoff_data_start = .;
302		*(.mmuoff.data.write)
303	}
304	. = ALIGN(SZ_2K);
305	.mmuoff.data.read : {
306		*(.mmuoff.data.read)
307		__mmuoff_data_end = .;
308	}
309
310	PECOFF_EDATA_PADDING
311	__pecoff_data_rawsize = ABSOLUTE(. - __initdata_begin);
312	_edata = .;
313
314	BSS_SECTION(SBSS_ALIGN, 0, 0)
315
316	. = ALIGN(PAGE_SIZE);
317	init_pg_dir = .;
318	. += INIT_DIR_SIZE;
319	init_pg_end = .;
320
321	. = ALIGN(SEGMENT_ALIGN);
322	__pecoff_data_size = ABSOLUTE(. - __initdata_begin);
323	_end = .;
324
325	STABS_DEBUG
326	DWARF_DEBUG
327	ELF_DETAILS
328
329	HEAD_SYMBOLS
330
331	/*
332	 * Sections that should stay zero sized, which is safer to
333	 * explicitly check instead of blindly discarding.
334	 */
335	.plt : {
336		*(.plt) *(.plt.*) *(.iplt) *(.igot .igot.plt)
337	}
338	ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
339
340	.data.rel.ro : { *(.data.rel.ro) }
341	ASSERT(SIZEOF(.data.rel.ro) == 0, "Unexpected RELRO detected!")
342}
343
344#include "image-vars.h"
345
346/*
347 * The HYP init code and ID map text can't be longer than a page each. The
348 * former is page-aligned, but the latter may not be with 16K or 64K pages, so
349 * it should also not cross a page boundary.
350 */
351ASSERT(__hyp_idmap_text_end - __hyp_idmap_text_start <= PAGE_SIZE,
352	"HYP init code too big")
353ASSERT(__idmap_text_end - (__idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
354	"ID map text too big or misaligned")
355#ifdef CONFIG_HIBERNATION
356ASSERT(__hibernate_exit_text_end - __hibernate_exit_text_start <= SZ_4K,
357       "Hibernate exit text is bigger than 4 KiB")
358#endif
359#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
360ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) <= 3*PAGE_SIZE,
361	"Entry trampoline text too big")
362#endif
363#ifdef CONFIG_KVM
364ASSERT(__hyp_bss_start == __bss_start, "HYP and Host BSS are misaligned")
365#endif
366/*
367 * If padding is applied before .head.text, virt<->phys conversions will fail.
368 */
369ASSERT(_text == KIMAGE_VADDR, "HEAD is misaligned")
370
371ASSERT(swapper_pg_dir - reserved_pg_dir == RESERVED_SWAPPER_OFFSET,
372       "RESERVED_SWAPPER_OFFSET is wrong!")
373
374#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
375ASSERT(swapper_pg_dir - tramp_pg_dir == TRAMP_SWAPPER_OFFSET,
376       "TRAMP_SWAPPER_OFFSET is wrong!")
377#endif
378
379#ifdef CONFIG_KEXEC_CORE
380/* kexec relocation code should fit into one KEXEC_CONTROL_PAGE_SIZE */
381ASSERT(__relocate_new_kernel_end - __relocate_new_kernel_start <= SZ_4K,
382       "kexec relocation code is bigger than 4 KiB")
383ASSERT(KEXEC_CONTROL_PAGE_SIZE >= SZ_4K, "KEXEC_CONTROL_PAGE_SIZE is broken")
384#endif
385