mirror of https://gitee.com/openkylin/linux.git
61 lines
1.2 KiB
ArmAsm
61 lines
1.2 KiB
ArmAsm
/*
|
|
* Copy to/from userspace with optional address space checking.
|
|
*
|
|
* Copyright 2004-2006 Atmel Corporation
|
|
*
|
|
* 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/errno.h>
|
|
|
|
#include <asm/page.h>
|
|
#include <asm/thread_info.h>
|
|
#include <asm/asm.h>
|
|
|
|
/*
|
|
* long strncpy_from_user(char *dst, const char *src, long count)
|
|
*
|
|
* On success, returns the length of the string, not including
|
|
* the terminating NUL.
|
|
*
|
|
* If the string is longer than count, returns count
|
|
*
|
|
* If userspace access fails, returns -EFAULT
|
|
*/
|
|
.text
|
|
.align 1
|
|
.global strncpy_from_user
|
|
.type strncpy_from_user, "function"
|
|
strncpy_from_user:
|
|
mov r9, -EFAULT
|
|
branch_if_kernel r8, __strncpy_from_user
|
|
ret_if_privileged r8, r11, r10, r9
|
|
|
|
.global __strncpy_from_user
|
|
.type __strncpy_from_user, "function"
|
|
__strncpy_from_user:
|
|
cp.w r10, 0
|
|
reteq 0
|
|
|
|
mov r9, r10
|
|
|
|
1: ld.ub r8, r11++
|
|
st.b r12++, r8
|
|
cp.w r8, 0
|
|
breq 2f
|
|
sub r9, 1
|
|
brne 1b
|
|
|
|
2: sub r10, r9
|
|
retal r10
|
|
|
|
.section .fixup, "ax"
|
|
.align 1
|
|
3: mov r12, -EFAULT
|
|
retal r12
|
|
|
|
.section __ex_table, "a"
|
|
.align 2
|
|
.long 1b, 3b
|