putuser.S 1.55 KB
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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
 *		r2, r3 contains the value
 * Outputs:	r0 is the error code
 *		lr corrupted
 *
 * No other registers must be altered.  (see include/asm-arm/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 <asm/errno.h>

	.global	__put_user_1
__put_user_1:
1:	strbt	r2, [r0]
	mov	r0, #0
	mov	pc, lr

	.global	__put_user_2
__put_user_2:
	mov	ip, r2, lsr #8
#ifndef __ARMEB__
2:	strbt	r2, [r0], #1
3:	strbt	ip, [r0]
#else
2:	strbt	ip, [r0], #1
3:	strbt	r2, [r0]
#endif
	mov	r0, #0
	mov	pc, lr

	.global	__put_user_4
__put_user_4:
4:	strt	r2, [r0]
	mov	r0, #0
	mov	pc, lr

	.global	__put_user_8
__put_user_8:
5:	strt	r2, [r0], #4
6:	strt	r3, [r0]
	mov	r0, #0
	mov	pc, lr

__put_user_bad:
	mov	r0, #-EFAULT
	mov	pc, lr

.section __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
.previous