From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001 From: Yuval Adam <_@yuv.al> Date: Wed, 30 Aug 2017 08:25:59 +0000 Subject: Initial file dump from open source release --- arch/mips/lib/strnlen_user.S | 46 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 arch/mips/lib/strnlen_user.S (limited to 'arch/mips/lib/strnlen_user.S') diff --git a/arch/mips/lib/strnlen_user.S b/arch/mips/lib/strnlen_user.S new file mode 100644 index 00000000..fcacea5e --- /dev/null +++ b/arch/mips/lib/strnlen_user.S @@ -0,0 +1,46 @@ +/* + * 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 +#include +#include + +#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 up to 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, .Lfault + +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), .Lfault) + PTR_ADDIU v0, 1 + bnez t0, 1b +1: PTR_SUBU v0, a0 + jr ra + END(__strnlen_user_asm) + +.Lfault: + move v0, zero + jr ra -- cgit v1.3.1