1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * linux/arch/unicore32/lib/strnlen_user.S 4 * 5 * Code specific to PKUnity SoC and UniCore ISA 6 * 7 * Copyright (C) 2001-2010 GUAN Xue-tao 8 */ 9#include <linux/linkage.h> 10#include <asm/assembler.h> 11#include <asm/errno.h> 12 13 .text 14 .align 5 15 16/* Prototype: unsigned long __strnlen_user(const char *str, long n) 17 * Purpose : get length of a string in user memory 18 * Params : str - address of string in user memory 19 * Returns : length of string *including terminator* 20 * or zero on exception, or n + 1 if too long 21 */ 22ENTRY(__strnlen_user) 23 mov r2, r0 241: 25 ldrusr r3, r0, 1 26 cxor.a r3, #0 27 beq 2f 28 sub.a r1, r1, #1 29 bne 1b 30 add r0, r0, #1 312: sub r0, r0, r2 32 mov pc, lr 33ENDPROC(__strnlen_user) 34 35 .pushsection .fixup,"ax" 36 .align 0 379001: mov r0, #0 38 mov pc, lr 39 .popsection 40