mirror_ubuntu-kernels/arch/arm64/include/asm/asm-extable.h
Tong Tiangen 4953fc3d32 arm64: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support
Currently, The extable type EX_TYPE_UACCESS_ERR_ZERO is used by
__get/put_kernel_nofault(), but those helpers are not uaccess type, so we
add a new extable type EX_TYPE_KACCESS_ERR_ZERO which can be used by
__get/put_kernel_no_fault().

This is also to prepare for distinguishing the two types in machine check
safe process.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220621072638.1273594-2-tongtiangen@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-06-28 12:11:00 +01:00

109 lines
2.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __ASM_ASM_EXTABLE_H
#define __ASM_ASM_EXTABLE_H
#define EX_TYPE_NONE 0
#define EX_TYPE_FIXUP 1
#define EX_TYPE_BPF 2
#define EX_TYPE_UACCESS_ERR_ZERO 3
#define EX_TYPE_KACCESS_ERR_ZERO 4
#define EX_TYPE_LOAD_UNALIGNED_ZEROPAD 5
#ifdef __ASSEMBLY__
#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \
.pushsection __ex_table, "a"; \
.align 2; \
.long ((insn) - .); \
.long ((fixup) - .); \
.short (type); \
.short (data); \
.popsection;
/*
* Create an exception table entry for `insn`, which will branch to `fixup`
* when an unhandled fault is taken.
*/
.macro _asm_extable, insn, fixup
__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)
.endm
/*
* Create an exception table entry for `insn` if `fixup` is provided. Otherwise
* do nothing.
*/
.macro _cond_extable, insn, fixup
.ifnc \fixup,
_asm_extable \insn, \fixup
.endif
.endm
#else /* __ASSEMBLY__ */
#include <linux/bits.h>
#include <linux/stringify.h>
#include <asm/gpr-num.h>
#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \
".pushsection __ex_table, \"a\"\n" \
".align 2\n" \
".long ((" insn ") - .)\n" \
".long ((" fixup ") - .)\n" \
".short (" type ")\n" \
".short (" data ")\n" \
".popsection\n"
#define _ASM_EXTABLE(insn, fixup) \
__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")
#define EX_DATA_REG_ERR_SHIFT 0
#define EX_DATA_REG_ERR GENMASK(4, 0)
#define EX_DATA_REG_ZERO_SHIFT 5
#define EX_DATA_REG_ZERO GENMASK(9, 5)
#define EX_DATA_REG(reg, gpr) \
"((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")"
#define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero) \
__DEFINE_ASM_GPR_NUMS \
__ASM_EXTABLE_RAW(#insn, #fixup, \
__stringify(EX_TYPE_UACCESS_ERR_ZERO), \
"(" \
EX_DATA_REG(ERR, err) " | " \
EX_DATA_REG(ZERO, zero) \
")")
#define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero) \
__DEFINE_ASM_GPR_NUMS \
__ASM_EXTABLE_RAW(#insn, #fixup, \
__stringify(EX_TYPE_KACCESS_ERR_ZERO), \
"(" \
EX_DATA_REG(ERR, err) " | " \
EX_DATA_REG(ZERO, zero) \
")")
#define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err) \
_ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr)
#define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err) \
_ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr)
#define EX_DATA_REG_DATA_SHIFT 0
#define EX_DATA_REG_DATA GENMASK(4, 0)
#define EX_DATA_REG_ADDR_SHIFT 5
#define EX_DATA_REG_ADDR GENMASK(9, 5)
#define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr) \
__DEFINE_ASM_GPR_NUMS \
__ASM_EXTABLE_RAW(#insn, #fixup, \
__stringify(EX_TYPE_LOAD_UNALIGNED_ZEROPAD), \
"(" \
EX_DATA_REG(DATA, data) " | " \
EX_DATA_REG(ADDR, addr) \
")")
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ASM_EXTABLE_H */