44 lines
981 B
ArmAsm
44 lines
981 B
ArmAsm
/*
|
|
* linux/arch/arm/lib/strncpy_from_user.S
|
|
*
|
|
* Copyright (C) 1995-2000 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.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/errno.h>
|
|
|
|
.text
|
|
.align 5
|
|
|
|
/*
|
|
* Copy a string from user space to kernel space.
|
|
* r0 = dst, r1 = src, r2 = byte length
|
|
* returns the number of characters copied (strlen of copied string),
|
|
* -EFAULT on exception, or "len" if we fill the whole buffer
|
|
*/
|
|
ENTRY(__strncpy_from_user)
|
|
mov ip, r1
|
|
1: subs r2, r2, #1
|
|
ldrusr r3, r1, 1, pl
|
|
bmi 2f
|
|
strb r3, [r0], #1
|
|
teq r3, #0
|
|
bne 1b
|
|
sub r1, r1, #1 @ take NUL character out of count
|
|
2: sub r0, r1, ip
|
|
mov pc, lr
|
|
ENDPROC(__strncpy_from_user)
|
|
|
|
.pushsection .fixup,"ax"
|
|
.align 0
|
|
9001: mov r3, #0
|
|
strb r3, [r0, #0] @ null terminate
|
|
mov r0, #-EFAULT
|
|
mov pc, lr
|
|
.popsection
|
|
|