linux-stable/arch/arm64/kernel/image.h
Ard Biesheuvel 120dc60d0b arm64: get rid of TEXT_OFFSET
TEXT_OFFSET serves no purpose, and for this reason, it was redefined
as 0x0 in the v5.8 timeframe. Since this does not appear to have caused
any issues that require us to revisit that decision, let's get rid of the
macro entirely, along with any references to it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-07 15:00:52 +01:00

67 lines
2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Linker script macros to generate Image header fields.
*
* Copyright (C) 2014 ARM Ltd.
*/
#ifndef __ARM64_KERNEL_IMAGE_H
#define __ARM64_KERNEL_IMAGE_H
#ifndef LINKER_SCRIPT
#error This file should only be included in vmlinux.lds.S
#endif
#include <asm/image.h>
/*
* 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)
#define __HEAD_FLAG(field) (__HEAD_FLAG_##field << \
ARM64_IMAGE_FLAG_##field##_SHIFT)
#ifdef CONFIG_CPU_BIG_ENDIAN
#define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_BE
#else
#define __HEAD_FLAG_BE ARM64_IMAGE_FLAG_LE
#endif
#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
#define __HEAD_FLAG_PHYS_BASE 1
#define __HEAD_FLAGS (__HEAD_FLAG(BE) | \
__HEAD_FLAG(PAGE_SIZE) | \
__HEAD_FLAG(PHYS_BASE))
/*
* 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_flags_le, __HEAD_FLAGS);
#endif /* __ARM64_KERNEL_IMAGE_H */