| /* | |
| * 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 |