| GuanXuetao | 77c93b2 | 2011-02-26 18:49:26 +0800 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/unicore32/lib/strnlen_user.S |
| 3 | * |
| 4 | * Code specific to PKUnity SoC and UniCore ISA |
| 5 | * |
| 6 | * Copyright (C) 2001-2010 GUAN Xue-tao |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | #include <linux/linkage.h> |
| 13 | #include <asm/assembler.h> |
| 14 | #include <asm/errno.h> |
| 15 | |
| 16 | .text |
| 17 | .align 5 |
| 18 | |
| 19 | /* Prototype: unsigned long __strnlen_user(const char *str, long n) |
| 20 | * Purpose : get length of a string in user memory |
| 21 | * Params : str - address of string in user memory |
| 22 | * Returns : length of string *including terminator* |
| 23 | * or zero on exception, or n + 1 if too long |
| 24 | */ |
| 25 | ENTRY(__strnlen_user) |
| 26 | mov r2, r0 |
| 27 | 1: |
| 28 | ldrusr r3, r0, 1 |
| 29 | cxor.a r3, #0 |
| 30 | beq 2f |
| 31 | sub.a r1, r1, #1 |
| 32 | bne 1b |
| 33 | add r0, r0, #1 |
| 34 | 2: sub r0, r0, r2 |
| 35 | mov pc, lr |
| 36 | ENDPROC(__strnlen_user) |
| 37 | |
| 38 | .pushsection .fixup,"ax" |
| 39 | .align 0 |
| 40 | 9001: mov r0, #0 |
| 41 | mov pc, lr |
| 42 | .popsection |
