WSL2-Linux-Kernel/arch/arm/lib/putuser.S

75 строки
1.5 KiB
ArmAsm

/*
* 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