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 */ 25ENTRY(__strnlen_user) 26 mov r2, r0 271: 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, #1 342: sub r0, r0, r2 35 mov pc, lr 36ENDPROC(__strnlen_user) 37 38 .pushsection .fixup,"ax" 39 .align 0 409001: mov r0, #0 41 mov pc, lr 42 .popsection 43