1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (c) 1996, 1998, 1999 by Ralf Baechle 7 * Copyright (c) 1999 Silicon Graphics, Inc. 8 */ 9#include <asm/asm.h> 10#include <asm/offset.h> 11#include <asm/regdef.h> 12#include <asm/sgidefs.h> 13 14#define EX(insn,reg,addr,handler) \ 159: insn reg, addr; \ 16 .section __ex_table,"a"; \ 17 PTR 9b, handler; \ 18 .previous 19 20/* 21 * Return the size of a string (including the ending 0) 22 * 23 * Return 0 for error, len of string but at max a1 otherwise 24 * 25 * Note: for performance reasons we deliberately accept that a user may 26 * make strlen_user and strnlen_user access the first few KSEG0 27 * bytes. There's nothing secret there ... 28 */ 29LEAF(__strnlen_user_asm) 30 lw v0, THREAD_CURDS($28) # pointer ok? 31 and v0, a0 32 bltz v0, fault 33 34FEXPORT(__strnlen_user_nocheck_asm) 35 .type __strnlen_user_nocheck_asm,@function 36 move v0, a0 37 addu a1, a0 # stop pointer 38 .set noreorder 391: beq v0, a1, 1f # limit reached? 40 addiu v0, 1 41 .set reorder 42 EX(lb, t0, -1(v0), fault) 43 bnez t0, 1b 441: subu v0, a0 45 jr ra 46 END(__strnlen_user_asm) 47 48fault: move v0, zero 49 jr ra 50