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1da177e4 LT |
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> | |
048eb582 | 10 | #include <asm/asm-offsets.h> |
1da177e4 LT |
11 | #include <asm/regdef.h> |
12 | ||
13 | #define EX(insn,reg,addr,handler) \ | |
14 | 9: insn reg, addr; \ | |
15 | .section __ex_table,"a"; \ | |
16 | PTR 9b, handler; \ | |
17 | .previous | |
18 | ||
19 | /* | |
25985edc | 20 | * Return the size of a string including the ending NUL character up to a |
1da177e4 LT |
21 | * maximum of a1 or 0 in case of error. |
22 | * | |
23 | * Note: for performance reasons we deliberately accept that a user may | |
70342287 RB |
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 ... | |
1da177e4 | 27 | */ |
c48be43e MC |
28 | .macro __BUILD_STRNLEN_ASM func |
29 | LEAF(__strnlen_\func\()_asm) | |
1da177e4 LT |
30 | LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? |
31 | and v0, a0 | |
c48be43e | 32 | bnez v0, .Lfault\@ |
1da177e4 | 33 | |
c48be43e | 34 | FEXPORT(__strnlen_\func\()_nocheck_asm) |
1da177e4 LT |
35 | move v0, a0 |
36 | PTR_ADDU a1, a0 # stop pointer | |
37 | 1: beq v0, a1, 1f # limit reached? | |
c48be43e | 38 | EX(lb, t0, (v0), .Lfault\@) |
3e9f37e8 | 39 | PTR_ADDIU v0, 1 |
1da177e4 LT |
40 | bnez t0, 1b |
41 | 1: PTR_SUBU v0, a0 | |
42 | jr ra | |
c48be43e | 43 | END(__strnlen_\func\()_asm) |
1da177e4 | 44 | |
c48be43e | 45 | .Lfault\@: |
c5ec1983 | 46 | move v0, zero |
1da177e4 | 47 | jr ra |
c48be43e MC |
48 | .endm |
49 | ||
50 | __BUILD_STRNLEN_ASM user |