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Diffstat (limited to 'arch/arm/lib/getuser.S')
| -rw-r--r-- | arch/arm/lib/getuser.S | 78 | 
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/arm/lib/getuser.S b/arch/arm/lib/getuser.S new file mode 100644 index 00000000000..64aa6f4fe5e --- /dev/null +++ b/arch/arm/lib/getuser.S @@ -0,0 +1,78 @@ +/* + *  linux/arch/arm/lib/getuser.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. + * + * __get_user_X + * + * Inputs:	r0 contains the address + * Outputs:	r0 is the error code + *		r2, r3 contains the zero-extended value + *		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 __get_user_bad is not global. + */ +#include <asm/constants.h> +#include <asm/thread_info.h> +#include <asm/errno.h> + +	.global	__get_user_1 +__get_user_1: +1:	ldrbt	r2, [r0] +	mov	r0, #0 +	mov	pc, lr + +	.global	__get_user_2 +__get_user_2: +2:	ldrbt	r2, [r0], #1 +3:	ldrbt	r3, [r0] +#ifndef __ARMEB__ +	orr	r2, r2, r3, lsl #8 +#else +	orr	r2, r3, r2, lsl #8 +#endif +	mov	r0, #0 +	mov	pc, lr + +	.global	__get_user_4 +__get_user_4: +4:	ldrt	r2, [r0] +	mov	r0, #0 +	mov	pc, lr + +	.global	__get_user_8 +__get_user_8: +5:	ldrt	r2, [r0], #4 +6:	ldrt	r3, [r0] +	mov	r0, #0 +	mov	pc, lr + +__get_user_bad_8: +	mov	r3, #0 +__get_user_bad: +	mov	r2, #0 +	mov	r0, #-EFAULT +	mov	pc, lr + +.section __ex_table, "a" +	.long	1b, __get_user_bad +	.long	2b, __get_user_bad +	.long	3b, __get_user_bad +	.long	4b, __get_user_bad +	.long	5b, __get_user_bad_8 +	.long	6b, __get_user_bad_8 +.previous  |