copy_from_user.S
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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
*/
#include <linux/linkage.h>
#include <asm/asm-uaccess.h>
#include <asm/assembler.h>
#include <asm/cache.h>
/*
* Copy from user space to a kernel buffer (alignment handled by the hardware)
*
* Parameters:
* x0 - to
* x1 - from
* x2 - n
* Returns:
* x0 - bytes not copied
*/
.macro ldrb1 reg, ptr, val
uao_user_alternative 9998f, ldrb, ldtrb, \reg, \ptr, \val
.endm
.macro strb1 reg, ptr, val
strb \reg, [\ptr], \val
.endm
.macro ldrh1 reg, ptr, val
uao_user_alternative 9998f, ldrh, ldtrh, \reg, \ptr, \val
.endm
.macro strh1 reg, ptr, val
strh \reg, [\ptr], \val
.endm
.macro ldr1 reg, ptr, val
uao_user_alternative 9998f, ldr, ldtr, \reg, \ptr, \val
.endm
.macro str1 reg, ptr, val
str \reg, [\ptr], \val
.endm
.macro ldp1 reg1, reg2, ptr, val
uao_ldp 9998f, \reg1, \reg2, \ptr, \val
.endm
.macro stp1 reg1, reg2, ptr, val
stp \reg1, \reg2, [\ptr], \val
.endm
end .req x5
SYM_FUNC_START(__arch_copy_from_user)
add end, x0, x2
#include "copy_template.S"
mov x0, #0 // Nothing to copy
ret
SYM_FUNC_END(__arch_copy_from_user)
EXPORT_SYMBOL(__arch_copy_from_user)
.section .fixup,"ax"
.align 2
9998: sub x0, end, dst // bytes not copied
ret
.previous