Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Sam Ravnborg | 048eb58 | 2005-09-09 22:32:31 +0200 | [diff] [blame] | 10 | #include <asm/asm-offsets.h> |
Paul Burton | d6cb671 | 2016-11-07 11:14:14 +0000 | [diff] [blame] | 11 | #include <asm/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <asm/regdef.h> |
| 13 | |
| 14 | #define EX(insn,reg,addr,handler) \ |
| 15 | 9: insn reg, addr; \ |
| 16 | .section __ex_table,"a"; \ |
| 17 | PTR 9b, handler; \ |
| 18 | .previous |
| 19 | |
| 20 | /* |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 21 | * Return the size of a string including the ending NUL character up to a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | * maximum of a1 or 0 in case of error. |
| 23 | * |
| 24 | * Note: for performance reasons we deliberately accept that a user may |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 25 | * make strlen_user and strnlen_user access the first few KSEG0 |
| 26 | * bytes. There's nothing secret there. On 64-bit accessing beyond |
| 27 | * the maximum is a tad hairier ... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | */ |
Thomas Bogendoerfer | 04324f4 | 2021-04-01 14:56:37 +0200 | [diff] [blame] | 29 | LEAF(__strnlen_user_asm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | move v0, a0 |
| 31 | PTR_ADDU a1, a0 # stop pointer |
Maciej W. Rozycki | c4fca4f | 2015-05-28 17:46:49 +0100 | [diff] [blame] | 32 | 1: |
| 33 | #ifdef CONFIG_CPU_DADDI_WORKAROUNDS |
| 34 | .set noat |
| 35 | li AT, 1 |
| 36 | #endif |
| 37 | beq v0, a1, 1f # limit reached? |
Thomas Bogendoerfer | 04324f4 | 2021-04-01 14:56:37 +0200 | [diff] [blame] | 38 | #ifdef CONFIG_EVA |
| 39 | .set push |
| 40 | .set eva |
| 41 | EX(lbe, t0, (v0), .Lfault) |
| 42 | .set pop |
| 43 | #else |
| 44 | EX(lb, t0, (v0), .Lfault) |
| 45 | #endif |
Ralf Baechle | 0097761 | 2014-11-04 11:54:29 +0100 | [diff] [blame] | 46 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | bnez t0, 1b |
Maciej W. Rozycki | c4fca4f | 2015-05-28 17:46:49 +0100 | [diff] [blame] | 48 | 1: |
| 49 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS |
| 50 | PTR_ADDIU v0, 1 |
| 51 | #else |
| 52 | PTR_ADDU v0, AT |
| 53 | .set at |
| 54 | #endif |
Ralf Baechle | 0097761 | 2014-11-04 11:54:29 +0100 | [diff] [blame] | 55 | .set reorder |
| 56 | PTR_SUBU v0, a0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | jr ra |
Thomas Bogendoerfer | 04324f4 | 2021-04-01 14:56:37 +0200 | [diff] [blame] | 58 | END(__strnlen_user_asm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Thomas Bogendoerfer | 04324f4 | 2021-04-01 14:56:37 +0200 | [diff] [blame] | 60 | .Lfault: |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 61 | move v0, zero |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | jr ra |
Markos Chandras | c48be43 | 2014-01-02 16:19:49 +0000 | [diff] [blame] | 63 | |
Thomas Bogendoerfer | 04324f4 | 2021-04-01 14:56:37 +0200 | [diff] [blame] | 64 | EXPORT_SYMBOL(__strnlen_user_asm) |