/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle * Copyright (c) 1999 Silicon Graphics, Inc. */ #include <asm/asm.h> #include <asm/asm-offsets.h> #include <asm/regdef.h> #define EX(insn,reg,addr,handler) \ 9: insn reg, addr; \ .section __ex_table,"a"; \ PTR 9b, handler; \ .previous /* * Return the size of a string including the ending NUL character upto a * maximum of a1 or 0 in case of error. * * Note: for performance reasons we deliberately accept that a user may * make strlen_user and strnlen_user access the first few KSEG0 * bytes. There's nothing secret there. On 64-bit accessing beyond * the maximum is a tad hairier ... */ LEAF(__strnlen_user_asm) LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? and v0, a0 bnez v0, fault FEXPORT(__strnlen_user_nocheck_asm) move v0, a0 PTR_ADDU a1, a0 # stop pointer 1: beq v0, a1, 1f # limit reached? EX(lb, t0, (v0), fault) PTR_ADDU v0, 1 bnez t0, 1b 1: PTR_SUBU v0, a0 jr ra END(__strnlen_user_asm) fault: move v0, zero jr ra