1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
* Copyright (c) 1999 Silicon Graphics, Inc.
*/
#include <asm/asm.h>
#include <asm/offset.h>
#include <asm/regdef.h>
#define EX(insn,reg,addr,handler) \
9: insn reg, addr; \
.section __ex_table,"a"; \
PTR 9b, handler; \
.previous
/*
* Return the size of a string including the ending NUL character upto a
* maximum of a1 or 0 in case of error.
*
* Note: for performance reasons we deliberately accept that a user may
* make strlen_user and strnlen_user access the first few KSEG0
* bytes. There's nothing secret there. On 64-bit accessing beyond
* the maximum is a tad hairier ...
*/
LEAF(__strnlen_user_asm)
LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
and v0, a0
bnez v0, fault
FEXPORT(__strnlen_user_nocheck_asm)
move v0, a0
PTR_ADDU a1, a0 # stop pointer
1: beq v0, a1, 1f # limit reached?
EX(lb, t0, (v0), fault)
PTR_ADDU v0, 1
bnez t0, 1b
1: PTR_SUBU v0, a0
jr ra
END(__strnlen_user_asm)
fault: move v0, zero
jr ra
|
