forked from Minki/linux
66 lines
1.4 KiB
ArmAsm
66 lines
1.4 KiB
ArmAsm
|
/*
|
||
|
|
* 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/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
|
||
|
|
|
||
|
|
__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
|
||
|
|
.previous
|