linux/arch/arm64/lib/copy_to_user.S
Yang Shi bffe1baff5 arm64: kasan: instrument user memory access API
The upstream commit 1771c6e1a5
("x86/kasan: instrument user memory access API") added KASAN instrument to
x86 user memory access API, so added such instrument to ARM64 too.

Define __copy_to/from_user in C in order to add kasan_check_read/write call,
rename assembly implementation to __arch_copy_to/from_user.

Tested by test_kasan module.

Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-06-21 15:37:18 +01:00

84 lines
2.0 KiB
ArmAsm

/*
* Copyright (C) 2012 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/>.
*/
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/assembler.h>
#include <asm/cache.h>
#include <asm/cpufeature.h>
#include <asm/sysreg.h>
/*
* Copy to user space from a kernel buffer (alignment handled by the hardware)
*
* Parameters:
* x0 - to
* x1 - from
* x2 - n
* Returns:
* x0 - bytes not copied
*/
.macro ldrb1 ptr, regB, val
ldrb \ptr, [\regB], \val
.endm
.macro strb1 ptr, regB, val
uao_user_alternative 9998f, strb, sttrb, \ptr, \regB, \val
.endm
.macro ldrh1 ptr, regB, val
ldrh \ptr, [\regB], \val
.endm
.macro strh1 ptr, regB, val
uao_user_alternative 9998f, strh, sttrh, \ptr, \regB, \val
.endm
.macro ldr1 ptr, regB, val
ldr \ptr, [\regB], \val
.endm
.macro str1 ptr, regB, val
uao_user_alternative 9998f, str, sttr, \ptr, \regB, \val
.endm
.macro ldp1 ptr, regB, regC, val
ldp \ptr, \regB, [\regC], \val
.endm
.macro stp1 ptr, regB, regC, val
uao_stp 9998f, \ptr, \regB, \regC, \val
.endm
end .req x5
ENTRY(__arch_copy_to_user)
ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
CONFIG_ARM64_PAN)
add end, x0, x2
#include "copy_template.S"
ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
CONFIG_ARM64_PAN)
mov x0, #0
ret
ENDPROC(__arch_copy_to_user)
.section .fixup,"ax"
.align 2
9998: sub x0, end, dst // bytes not copied
ret
.previous