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