[mirror_ubuntu-zesty-kernel.git] / arch / arm64 / kernel / image.h

/*
 * Linker script macros to generate Image header fields.
 *
 * Copyright (C) 2014 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASM_IMAGE_H
#define __ASM_IMAGE_H

#ifndef LINKER_SCRIPT
#error This file should only be included in vmlinux.lds.S
#endif

/*
 * There aren't any ELF relocations we can use to endian-swap values known only
 * at link time (e.g. the subtraction of two symbol addresses), so we must get
 * the linker to endian-swap certain values before emitting them.
 *
 * Note that, in order for this to work when building the ELF64 PIE executable
 * (for KASLR), these values should not be referenced via R_AARCH64_ABS64
 * relocations, since these are fixed up at runtime rather than at build time
 * when PIE is in effect. So we need to split them up in 32-bit high and low
 * words.
 */
#ifdef CONFIG_CPU_BIG_ENDIAN
#define DATA_LE32(data)				\
	((((data) & 0x000000ff) << 24) |	\
	 (((data) & 0x0000ff00) << 8)  |	\
	 (((data) & 0x00ff0000) >> 8)  |	\
	 (((data) & 0xff000000) >> 24))
#else
#define DATA_LE32(data) ((data) & 0xffffffff)
#endif

#define DEFINE_IMAGE_LE64(sym, data)				\
	sym##_lo32 = DATA_LE32((data) & 0xffffffff);		\
	sym##_hi32 = DATA_LE32((data) >> 32)

#ifdef CONFIG_CPU_BIG_ENDIAN
#define __HEAD_FLAG_BE		1
#else
#define __HEAD_FLAG_BE		0
#endif

#define __HEAD_FLAG_PAGE_SIZE	((PAGE_SHIFT - 10) / 2)

#define __HEAD_FLAG_PHYS_BASE	1

#define __HEAD_FLAGS		((__HEAD_FLAG_BE << 0) |	\
				 (__HEAD_FLAG_PAGE_SIZE << 1) |	\
				 (__HEAD_FLAG_PHYS_BASE << 3))

/*
 * These will output as part of the Image header, which should be little-endian
 * regardless of the endianness of the kernel. While constant values could be
 * endian swapped in head.S, all are done here for consistency.
 */
#define HEAD_SYMBOLS						\
	DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text);	\
	DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET);	\
	DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);

#ifdef CONFIG_EFI

__efistub_stext_offset = stext - _text;

/*
 * Prevent the symbol aliases below from being emitted into the kallsyms
 * table, by forcing them to be absolute symbols (which are conveniently
 * ignored by scripts/kallsyms) rather than section relative symbols.
 * The distinction is only relevant for partial linking, and only for symbols
 * that are defined within a section declaration (which is not the case for
 * the definitions below) so the resulting values will be identical.
 */
#define KALLSYMS_HIDE(sym)	ABSOLUTE(sym)

/*
 * The EFI stub has its own symbol namespace prefixed by __efistub_, to
 * isolate it from the kernel proper. The following symbols are legally
 * accessed by the stub, so provide some aliases to make them accessible.
 * Only include data symbols here, or text symbols of functions that are
 * guaranteed to be safe when executed at another offset than they were
 * linked at. The routines below are all implemented in assembler in a
 * position independent manner
 */
__efistub_memcmp		= KALLSYMS_HIDE(__pi_memcmp);
__efistub_memchr		= KALLSYMS_HIDE(__pi_memchr);
__efistub_memcpy		= KALLSYMS_HIDE(__pi_memcpy);
__efistub_memmove		= KALLSYMS_HIDE(__pi_memmove);
__efistub_memset		= KALLSYMS_HIDE(__pi_memset);
__efistub_strlen		= KALLSYMS_HIDE(__pi_strlen);
__efistub_strnlen		= KALLSYMS_HIDE(__pi_strnlen);
__efistub_strcmp		= KALLSYMS_HIDE(__pi_strcmp);
__efistub_strncmp		= KALLSYMS_HIDE(__pi_strncmp);
__efistub___flush_dcache_area	= KALLSYMS_HIDE(__pi___flush_dcache_area);

#ifdef CONFIG_KASAN
__efistub___memcpy		= KALLSYMS_HIDE(__pi_memcpy);
__efistub___memmove		= KALLSYMS_HIDE(__pi_memmove);
__efistub___memset		= KALLSYMS_HIDE(__pi_memset);
#endif

__efistub__text			= KALLSYMS_HIDE(_text);
__efistub__end			= KALLSYMS_HIDE(_end);
__efistub__edata		= KALLSYMS_HIDE(_edata);
__efistub_screen_info		= KALLSYMS_HIDE(screen_info);

#endif

#endif /* __ASM_IMAGE_H */
Commit	Line	Data
a2c1d73b MR	1	/*
	2	* Linker script macros to generate Image header fields.
	3	*
	4	* Copyright (C) 2014 ARM Ltd.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18	#ifndef __ASM_IMAGE_H
	19	#define __ASM_IMAGE_H
	20
	21	#ifndef LINKER_SCRIPT
	22	#error This file should only be included in vmlinux.lds.S
	23	#endif
	24
	25	/*
	26	* There aren't any ELF relocations we can use to endian-swap values known only
	27	* at link time (e.g. the subtraction of two symbol addresses), so we must get
	28	* the linker to endian-swap certain values before emitting them.
6ad1fe5d AB	29	*
	30	* Note that, in order for this to work when building the ELF64 PIE executable
	31	* (for KASLR), these values should not be referenced via R_AARCH64_ABS64
	32	* relocations, since these are fixed up at runtime rather than at build time
	33	* when PIE is in effect. So we need to split them up in 32-bit high and low
	34	* words.
a2c1d73b MR	35	*/
a2c1d73b MR	36	#ifdef CONFIG_CPU_BIG_ENDIAN
6ad1fe5d AB	37	#define DATA_LE32(data) \
	38	((((data) & 0x000000ff) << 24) \| \
	39	(((data) & 0x0000ff00) << 8) \| \
	40	(((data) & 0x00ff0000) >> 8) \| \
	41	(((data) & 0xff000000) >> 24))
a2c1d73b	42	#else
6ad1fe5d	43	#define DATA_LE32(data) ((data) & 0xffffffff)
a2c1d73b MR	44	#endif
a2c1d73b MR	45
6ad1fe5d AB	46	#define DEFINE_IMAGE_LE64(sym, data) \
	47	sym##_lo32 = DATA_LE32((data) & 0xffffffff); \
	48	sym##_hi32 = DATA_LE32((data) >> 32)
	49
a2c1d73b	50	#ifdef CONFIG_CPU_BIG_ENDIAN
a7f8de16	51	#define __HEAD_FLAG_BE 1
a2c1d73b	52	#else
a7f8de16	53	#define __HEAD_FLAG_BE 0
a2c1d73b MR	54	#endif
a2c1d73b MR	55
a7f8de16	56	#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
9d372c9f	57
a7f8de16	58	#define __HEAD_FLAG_PHYS_BASE 1
9d372c9f	59
a7f8de16 AB	60	#define __HEAD_FLAGS ((__HEAD_FLAG_BE << 0) \| \
	61	(__HEAD_FLAG_PAGE_SIZE << 1) \| \
	62	(__HEAD_FLAG_PHYS_BASE << 3))
a2c1d73b MR	63
	64	/*
	65	* These will output as part of the Image header, which should be little-endian
	66	* regardless of the endianness of the kernel. While constant values could be
	67	* endian swapped in head.S, all are done here for consistency.
	68	*/
	69	#define HEAD_SYMBOLS \
6ad1fe5d AB	70	DEFINE_IMAGE_LE64(_kernel_size_le, _end - _text); \
	71	DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET); \
	72	DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
a2c1d73b	73
e8f3010f AB	74	#ifdef CONFIG_EFI
e8f3010f AB	75
546c8c44 AB	76	__efistub_stext_offset = stext - _text;
546c8c44 AB	77
75feee3d AB	78	/*
	79	* Prevent the symbol aliases below from being emitted into the kallsyms
	80	* table, by forcing them to be absolute symbols (which are conveniently
	81	* ignored by scripts/kallsyms) rather than section relative symbols.
	82	* The distinction is only relevant for partial linking, and only for symbols
	83	* that are defined within a section declaration (which is not the case for
	84	* the definitions below) so the resulting values will be identical.
	85	*/
	86	#define KALLSYMS_HIDE(sym) ABSOLUTE(sym)
	87
e8f3010f AB	88	/*
	89	* The EFI stub has its own symbol namespace prefixed by __efistub_, to
	90	* isolate it from the kernel proper. The following symbols are legally
	91	* accessed by the stub, so provide some aliases to make them accessible.
	92	* Only include data symbols here, or text symbols of functions that are
	93	* guaranteed to be safe when executed at another offset than they were
	94	* linked at. The routines below are all implemented in assembler in a
	95	* position independent manner
	96	*/
75feee3d AB	97	__efistub_memcmp = KALLSYMS_HIDE(__pi_memcmp);
	98	__efistub_memchr = KALLSYMS_HIDE(__pi_memchr);
	99	__efistub_memcpy = KALLSYMS_HIDE(__pi_memcpy);
	100	__efistub_memmove = KALLSYMS_HIDE(__pi_memmove);
	101	__efistub_memset = KALLSYMS_HIDE(__pi_memset);
	102	__efistub_strlen = KALLSYMS_HIDE(__pi_strlen);
7f4e3462	103	__efistub_strnlen = KALLSYMS_HIDE(__pi_strnlen);
75feee3d AB	104	__efistub_strcmp = KALLSYMS_HIDE(__pi_strcmp);
	105	__efistub_strncmp = KALLSYMS_HIDE(__pi_strncmp);
	106	__efistub___flush_dcache_area = KALLSYMS_HIDE(__pi___flush_dcache_area);
e8f3010f	107
39d114dd	108	#ifdef CONFIG_KASAN
75feee3d AB	109	__efistub___memcpy = KALLSYMS_HIDE(__pi_memcpy);
	110	__efistub___memmove = KALLSYMS_HIDE(__pi_memmove);
	111	__efistub___memset = KALLSYMS_HIDE(__pi_memset);
39d114dd AR	112	#endif
39d114dd AR	113
75feee3d AB	114	__efistub__text = KALLSYMS_HIDE(_text);
	115	__efistub__end = KALLSYMS_HIDE(_end);
	116	__efistub__edata = KALLSYMS_HIDE(_edata);
57fdb89a	117	__efistub_screen_info = KALLSYMS_HIDE(screen_info);
e8f3010f AB	118
	119	#endif
	120
a2c1d73b	121	#endif /* __ASM_IMAGE_H */