xref: /openbmc/linux/arch/arm64/kernel/vmlinux.lds.S (revision c3cee924bd855184d15bc4aa6088dcf8e2c1394c)
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#else
120#define TRAMP_TEXT
121#endif
122
123/*
124 * The size of the PE/COFF section that covers the kernel image, which
125 * runs from _stext to _edata, must be a round multiple of the PE/COFF
126 * FileAlignment, which we set to its minimum value of 0x200. '_stext'
127 * itself is 4 KB aligned, so padding out _edata to a 0x200 aligned
128 * boundary should be sufficient.
129 */
130PECOFF_FILE_ALIGNMENT = 0x200;
131
132#ifdef CONFIG_EFI
133#define PECOFF_EDATA_PADDING	\
134	.pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
135#else
136#define PECOFF_EDATA_PADDING
137#endif
138
139SECTIONS
140{
141	/*
142	 * XXX: The linker does not define how output sections are
143	 * assigned to input sections when there are multiple statements
144	 * matching the same input section name.  There is no documented
145	 * order of matching.
146	 */
147	DISCARDS
148	/DISCARD/ : {
149		*(.interp .dynamic)
150		*(.dynsym .dynstr .hash .gnu.hash)
151	}
152
153	. = KIMAGE_VADDR;
154
155	.head.text : {
156		_text = .;
157		HEAD_TEXT
158	}
159	.text : ALIGN(SEGMENT_ALIGN) {	/* Real text segment		*/
160		_stext = .;		/* Text and read-only data	*/
161			IRQENTRY_TEXT
162			SOFTIRQENTRY_TEXT
163			ENTRY_TEXT
164			TEXT_TEXT
165			SCHED_TEXT
166			CPUIDLE_TEXT
167			LOCK_TEXT
168			KPROBES_TEXT
169			HYPERVISOR_TEXT
170			IDMAP_TEXT
171			*(.gnu.warning)
172		. = ALIGN(16);
173		*(.got)			/* Global offset table		*/
174	}
175
176	/*
177	 * Make sure that the .got.plt is either completely empty or it
178	 * contains only the lazy dispatch entries.
179	 */
180	.got.plt : { *(.got.plt) }
181	ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18,
182	       "Unexpected GOT/PLT entries detected!")
183
184	. = ALIGN(SEGMENT_ALIGN);
185	_etext = .;			/* End of text section */
186
187	/* everything from this point to __init_begin will be marked RO NX */
188	RO_DATA(PAGE_SIZE)
189
190	HYPERVISOR_DATA_SECTIONS
191
192	/* code sections that are never executed via the kernel mapping */
193	.rodata.text : {
194		TRAMP_TEXT
195		HIBERNATE_TEXT
196		KEXEC_TEXT
197		. = ALIGN(PAGE_SIZE);
198	}
199
200	idmap_pg_dir = .;
201	. += PAGE_SIZE;
202
203#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
204	tramp_pg_dir = .;
205	. += PAGE_SIZE;
206#endif
207
208	reserved_pg_dir = .;
209	. += PAGE_SIZE;
210
211	swapper_pg_dir = .;
212	. += PAGE_SIZE;
213
214	. = ALIGN(SEGMENT_ALIGN);
215	__init_begin = .;
216	__inittext_begin = .;
217
218	INIT_TEXT_SECTION(8)
219
220	__exittext_begin = .;
221	.exit.text : {
222		EXIT_TEXT
223	}
224	__exittext_end = .;
225
226	. = ALIGN(4);
227	.altinstructions : {
228		__alt_instructions = .;
229		*(.altinstructions)
230		__alt_instructions_end = .;
231	}
232
233	. = ALIGN(SEGMENT_ALIGN);
234	__inittext_end = .;
235	__initdata_begin = .;
236
237	init_idmap_pg_dir = .;
238	. += INIT_IDMAP_DIR_SIZE;
239	init_idmap_pg_end = .;
240
241	.init.data : {
242		INIT_DATA
243		INIT_SETUP(16)
244		INIT_CALLS
245		CON_INITCALL
246		INIT_RAM_FS
247		*(.init.altinstructions .init.bss)	/* from the EFI stub */
248	}
249	.exit.data : {
250		EXIT_DATA
251	}
252
253	PERCPU_SECTION(L1_CACHE_BYTES)
254	HYPERVISOR_PERCPU_SECTION
255
256	HYPERVISOR_RELOC_SECTION
257
258	.rela.dyn : ALIGN(8) {
259		*(.rela .rela*)
260	}
261
262	__rela_offset	= ABSOLUTE(ADDR(.rela.dyn) - KIMAGE_VADDR);
263	__rela_size	= SIZEOF(.rela.dyn);
264
265#ifdef CONFIG_RELR
266	.relr.dyn : ALIGN(8) {
267		*(.relr.dyn)
268	}
269
270	__relr_offset	= ABSOLUTE(ADDR(.relr.dyn) - KIMAGE_VADDR);
271	__relr_size	= SIZEOF(.relr.dyn);
272#endif
273
274	. = ALIGN(SEGMENT_ALIGN);
275	__initdata_end = .;
276	__init_end = .;
277
278	_data = .;
279	_sdata = .;
280	RW_DATA(L1_CACHE_BYTES, PAGE_SIZE, THREAD_ALIGN)
281
282	/*
283	 * Data written with the MMU off but read with the MMU on requires
284	 * cache lines to be invalidated, discarding up to a Cache Writeback
285	 * Granule (CWG) of data from the cache. Keep the section that
286	 * requires this type of maintenance to be in its own Cache Writeback
287	 * Granule (CWG) area so the cache maintenance operations don't
288	 * interfere with adjacent data.
289	 */
290	.mmuoff.data.write : ALIGN(SZ_2K) {
291		__mmuoff_data_start = .;
292		*(.mmuoff.data.write)
293	}
294	. = ALIGN(SZ_2K);
295	.mmuoff.data.read : {
296		*(.mmuoff.data.read)
297		__mmuoff_data_end = .;
298	}
299
300	PECOFF_EDATA_PADDING
301	__pecoff_data_rawsize = ABSOLUTE(. - __initdata_begin);
302	_edata = .;
303
304	BSS_SECTION(SBSS_ALIGN, 0, 0)
305
306	. = ALIGN(PAGE_SIZE);
307	init_pg_dir = .;
308	. += INIT_DIR_SIZE;
309	init_pg_end = .;
310
311	. = ALIGN(SEGMENT_ALIGN);
312	__pecoff_data_size = ABSOLUTE(. - __initdata_begin);
313	_end = .;
314
315	STABS_DEBUG
316	DWARF_DEBUG
317	ELF_DETAILS
318
319	HEAD_SYMBOLS
320
321	/*
322	 * Sections that should stay zero sized, which is safer to
323	 * explicitly check instead of blindly discarding.
324	 */
325	.plt : {
326		*(.plt) *(.plt.*) *(.iplt) *(.igot .igot.plt)
327	}
328	ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
329
330	.data.rel.ro : { *(.data.rel.ro) }
331	ASSERT(SIZEOF(.data.rel.ro) == 0, "Unexpected RELRO detected!")
332}
333
334#include "image-vars.h"
335
336/*
337 * The HYP init code and ID map text can't be longer than a page each. The
338 * former is page-aligned, but the latter may not be with 16K or 64K pages, so
339 * it should also not cross a page boundary.
340 */
341ASSERT(__hyp_idmap_text_end - __hyp_idmap_text_start <= PAGE_SIZE,
342	"HYP init code too big")
343ASSERT(__idmap_text_end - (__idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
344	"ID map text too big or misaligned")
345#ifdef CONFIG_HIBERNATION
346ASSERT(__hibernate_exit_text_end - __hibernate_exit_text_start <= SZ_4K,
347       "Hibernate exit text is bigger than 4 KiB")
348#endif
349#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
350ASSERT((__entry_tramp_text_end - __entry_tramp_text_start) <= 3*PAGE_SIZE,
351	"Entry trampoline text too big")
352#endif
353#ifdef CONFIG_KVM
354ASSERT(__hyp_bss_start == __bss_start, "HYP and Host BSS are misaligned")
355#endif
356/*
357 * If padding is applied before .head.text, virt<->phys conversions will fail.
358 */
359ASSERT(_text == KIMAGE_VADDR, "HEAD is misaligned")
360
361ASSERT(swapper_pg_dir - reserved_pg_dir == RESERVED_SWAPPER_OFFSET,
362       "RESERVED_SWAPPER_OFFSET is wrong!")
363
364#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
365ASSERT(swapper_pg_dir - tramp_pg_dir == TRAMP_SWAPPER_OFFSET,
366       "TRAMP_SWAPPER_OFFSET is wrong!")
367#endif
368
369#ifdef CONFIG_KEXEC_CORE
370/* kexec relocation code should fit into one KEXEC_CONTROL_PAGE_SIZE */
371ASSERT(__relocate_new_kernel_end - __relocate_new_kernel_start <= SZ_4K,
372       "kexec relocation code is bigger than 4 KiB")
373ASSERT(KEXEC_CONTROL_PAGE_SIZE >= SZ_4K, "KEXEC_CONTROL_PAGE_SIZE is broken")
374#endif
375