diff options
Diffstat (limited to 'arch/arm64/lib/strnlen_user.S')
| -rw-r--r-- | arch/arm64/lib/strnlen_user.S | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/arm64/lib/strnlen_user.S b/arch/arm64/lib/strnlen_user.S new file mode 100644 index 000000000000..7f7b176a5646 --- /dev/null +++ b/arch/arm64/lib/strnlen_user.S @@ -0,0 +1,47 @@ +/* + * 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 |