| /* |
| * Based on arch/arm/lib/strnlen_user.S |
| * |
| * Copyright (C) 1995-2000 Russell King |
| * Copyright (C) 2012 ARM Ltd. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/assembler.h> |
| #include <asm/errno.h> |
| |
| .text |
| .align 5 |
| |
| /* Prototype: unsigned long __strnlen_user(const char *str, long n) |
| * Purpose : get length of a string in user memory |
| * Params : str - address of string in user memory |
| * Returns : length of string *including terminator* |
| * or zero on exception, or n if too long |
| */ |
| ENTRY(__strnlen_user) |
| mov x2, x0 |
| 1: subs x1, x1, #1 |
| b.mi 2f |
| USER(9f, ldrb w3, [x0], #1 ) |
| cbnz w3, 1b |
| 2: sub x0, x0, x2 |
| ret |
| ENDPROC(__strnlen_user) |
| |
| .section .fixup,"ax" |
| .align 0 |
| 9: mov x0, #0 |
| ret |
| .previous |