putuser.S
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/*
* linux/arch/arm/lib/putuser.S
*
* Copyright (C) 2001 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.
*
* Idea from x86 version, (C) Copyright 1998 Linus Torvalds
*
* These functions have a non-standard call interface to make
* them more efficient, especially as they return an error
* value in addition to the "real" return value.
*
* __put_user_X
*
* Inputs: r0 contains the address
* r1 contains the address limit, which must be preserved
* r2, r3 contains the value
* Outputs: r0 is the error code
* lr corrupted
*
* No other registers must be altered. (see <asm/uaccess.h>
* for specific ASM register usage).
*
* Note that ADDR_LIMIT is either 0 or 0xc0000000
* Note also that it is intended that __put_user_bad is not global.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/errno.h>
#include <asm/domain.h>
ENTRY(__put_user_1)
check_uaccess r0, 1, r1, ip, __put_user_bad
1: TUSER(strb) r2, [r0]
mov r0, #0
mov pc, lr
ENDPROC(__put_user_1)
ENTRY(__put_user_2)
check_uaccess r0, 2, r1, ip, __put_user_bad
mov ip, r2, lsr #8
#ifdef CONFIG_THUMB2_KERNEL
#ifndef __ARMEB__
2: TUSER(strb) r2, [r0]
3: TUSER(strb) ip, [r0, #1]
#else
2: TUSER(strb) ip, [r0]
3: TUSER(strb) r2, [r0, #1]
#endif
#else /* !CONFIG_THUMB2_KERNEL */
#ifndef __ARMEB__
2: TUSER(strb) r2, [r0], #1
3: TUSER(strb) ip, [r0]
#else
2: TUSER(strb) ip, [r0], #1
3: TUSER(strb) r2, [r0]
#endif
#endif /* CONFIG_THUMB2_KERNEL */
mov r0, #0
mov pc, lr
ENDPROC(__put_user_2)
ENTRY(__put_user_4)
check_uaccess r0, 4, r1, ip, __put_user_bad
4: TUSER(str) r2, [r0]
mov r0, #0
mov pc, lr
ENDPROC(__put_user_4)
ENTRY(__put_user_8)
check_uaccess r0, 8, r1, ip, __put_user_bad
#ifdef CONFIG_THUMB2_KERNEL
5: TUSER(str) r2, [r0]
6: TUSER(str) r3, [r0, #4]
#else
5: TUSER(str) r2, [r0], #4
6: TUSER(str) r3, [r0]
#endif
mov r0, #0
mov pc, lr
ENDPROC(__put_user_8)
__put_user_bad:
mov r0, #-EFAULT
mov pc, lr
ENDPROC(__put_user_bad)
.pushsection __ex_table, "a"
.long 1b, __put_user_bad
.long 2b, __put_user_bad
.long 3b, __put_user_bad
.long 4b, __put_user_bad
.long 5b, __put_user_bad
.long 6b, __put_user_bad
.popsection