linux/arch/arm/lib/clear_user.S
Stefan Agner e44fc38818 ARM: 8844/1: use unified assembler in assembly files
Use unified assembler syntax (UAL) in assembly files. Divided
syntax is considered deprecated. This will also allow to build
the kernel using LLVM's integrated assembler.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-02-26 11:26:07 +00:00

59 lines
1.4 KiB
ArmAsm

/*
* linux/arch/arm/lib/clear_user.S
*
* Copyright (C) 1995, 1996,1997,1998 Russell King
*
* 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.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/unwind.h>
.text
/* Prototype: unsigned long arm_clear_user(void *addr, size_t sz)
* Purpose : clear some user memory
* Params : addr - user memory address to clear
* : sz - number of bytes to clear
* Returns : number of bytes NOT cleared
*/
ENTRY(__clear_user_std)
WEAK(arm_clear_user)
UNWIND(.fnstart)
UNWIND(.save {r1, lr})
stmfd sp!, {r1, lr}
mov r2, #0
cmp r1, #4
blt 2f
ands ip, r0, #3
beq 1f
cmp ip, #2
strusr r2, r0, 1
strusr r2, r0, 1, le
strusr r2, r0, 1, lt
rsb ip, ip, #4
sub r1, r1, ip @ 7 6 5 4 3 2 1
1: subs r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7
strusr r2, r0, 4, pl, rept=2
bpl 1b
adds r1, r1, #4 @ 3 2 1 0 -1 -2 -3
strusr r2, r0, 4, pl
2: tst r1, #2 @ 1x 1x 0x 0x 1x 1x 0x
strusr r2, r0, 1, ne, rept=2
tst r1, #1 @ x1 x0 x1 x0 x1 x0 x1
it ne @ explicit IT needed for the label
USER( strbtne r2, [r0])
mov r0, #0
ldmfd sp!, {r1, pc}
UNWIND(.fnend)
ENDPROC(arm_clear_user)
ENDPROC(__clear_user_std)
.pushsection .text.fixup,"ax"
.align 0
9001: ldmfd sp!, {r0, pc}
.popsection