/* * 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