120 строки
2.2 KiB
ArmAsm
120 строки
2.2 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 <asm/page.h>
|
||
|
|
#include <asm/thread_info.h>
|
||
|
|
#include <asm/asm.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* __kernel_size_t
|
||
|
|
* __copy_user(void *to, const void *from, __kernel_size_t n)
|
||
|
|
*
|
||
|
|
* Returns the number of bytes not copied. Might be off by
|
||
|
|
* max 3 bytes if we get a fault in the main loop.
|
||
|
|
*
|
||
|
|
* The address-space checking functions simply fall through to
|
||
|
|
* the non-checking version.
|
||
|
|
*/
|
||
|
|
.text
|
||
|
|
.align 1
|
||
|
|
.global copy_from_user
|
||
|
|
.type copy_from_user, @function
|
||
|
|
copy_from_user:
|
||
|
|
branch_if_kernel r8, __copy_user
|
||
|
|
ret_if_privileged r8, r11, r10, r10
|
||
|
|
rjmp __copy_user
|
||
|
|
.size copy_from_user, . - copy_from_user
|
||
|
|
|
||
|
|
.global copy_to_user
|
||
|
|
.type copy_to_user, @function
|
||
|
|
copy_to_user:
|
||
|
|
branch_if_kernel r8, __copy_user
|
||
|
|
ret_if_privileged r8, r12, r10, r10
|
||
|
|
.size copy_to_user, . - copy_to_user
|
||
|
|
|
||
|
|
.global __copy_user
|
||
|
|
.type __copy_user, @function
|
||
|
|
__copy_user:
|
||
|
|
mov r9, r11
|
||
|
|
andl r9, 3, COH
|
||
|
|
brne 6f
|
||
|
|
|
||
|
|
/* At this point, from is word-aligned */
|
||
|
|
1: sub r10, 4
|
||
|
|
brlt 3f
|
||
|
|
|
||
|
|
2:
|
||
|
|
10: ld.w r8, r11++
|
||
|
|
11: st.w r12++, r8
|
||
|
|
sub r10, 4
|
||
|
|
brge 2b
|
||
|
|
|
||
|
|
3: sub r10, -4
|
||
|
|
reteq 0
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Handle unaligned count. Need to be careful with r10 here so
|
||
|
|
* that we return the correct value even if we get a fault
|
||
|
|
*/
|
||
|
|
4:
|
||
|
|
20: ld.ub r8, r11++
|
||
|
|
21: st.b r12++, r8
|
||
|
|
sub r10, 1
|
||
|
|
reteq 0
|
||
|
|
22: ld.ub r8, r11++
|
||
|
|
23: st.b r12++, r8
|
||
|
|
sub r10, 1
|
||
|
|
reteq 0
|
||
|
|
24: ld.ub r8, r11++
|
||
|
|
25: st.b r12++, r8
|
||
|
|
retal 0
|
||
|
|
|
||
|
|
/* Handle unaligned from-pointer */
|
||
|
|
6: cp.w r10, 4
|
||
|
|
brlt 4b
|
||
|
|
rsub r9, r9, 4
|
||
|
|
|
||
|
|
30: ld.ub r8, r11++
|
||
|
|
31: st.b r12++, r8
|
||
|
|
sub r10, 1
|
||
|
|
sub r9, 1
|
||
|
|
breq 1b
|
||
|
|
32: ld.ub r8, r11++
|
||
|
|
33: st.b r12++, r8
|
||
|
|
sub r10, 1
|
||
|
|
sub r9, 1
|
||
|
|
breq 1b
|
||
|
|
34: ld.ub r8, r11++
|
||
|
|
35: st.b r12++, r8
|
||
|
|
sub r10, 1
|
||
|
|
rjmp 1b
|
||
|
|
.size __copy_user, . - __copy_user
|
||
|
|
|
||
|
|
.section .fixup,"ax"
|
||
|
|
.align 1
|
||
|
|
19: sub r10, -4
|
||
|
|
29: retal r10
|
||
|
|
|
||
|
|
.section __ex_table,"a"
|
||
|
|
.align 2
|
||
|
|
.long 10b, 19b
|
||
|
|
.long 11b, 19b
|
||
|
|
.long 20b, 29b
|
||
|
|
.long 21b, 29b
|
||
|
|
.long 22b, 29b
|
||
|
|
.long 23b, 29b
|
||
|
|
.long 24b, 29b
|
||
|
|
.long 25b, 29b
|
||
|
|
.long 30b, 29b
|
||
|
|
.long 31b, 29b
|
||
|
|
.long 32b, 29b
|
||
|
|
.long 33b, 29b
|
||
|
|
.long 34b, 29b
|
||
|
|
.long 35b, 29b
|