From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760128Ab2C2WO2 (ORCPT ); Thu, 29 Mar 2012 18:14:28 -0400 Received: from shards.monkeyblade.net ([198.137.202.13]:44455 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753978Ab2C2WOV convert rfc822-to-8bit (ORCPT ); Thu, 29 Mar 2012 18:14:21 -0400 Date: Thu, 29 Mar 2012 18:13:11 -0400 (EDT) Message-Id: <20120329.181311.91358289912662112.davem@davemloft.net> To: eric.dumazet@gmail.com Cc: zhuangfeiran@ict.ac.cn, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fix a bug in emitting the 16-bit immediate operand of AND From: David Miller In-Reply-To: <1333021525.3402.22.camel@edumazet-laptop> References: <4F742AE4.6050006@ict.ac.cn> <1333021525.3402.22.camel@edumazet-laptop> X-Mailer: Mew version 6.4 on Emacs 23.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Thu, 29 Mar 2012 15:13:15 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet Date: Thu, 29 Mar 2012 13:45:25 +0200 > Le jeudi 29 mars 2012 à 17:27 +0800, zhuangfeiran@ict.ac.cn a écrit : >> When K >= 0xFFFF0000, AND needs the two least significant bytes of K as >> its operand, but EMIT2() gives it the least significant byte of K and >> 0x2. EMIT() should be used here to replace EMIT2(). >> >> Signed-off-by: Feiran Zhuang >> --- >> arch/x86/net/bpf_jit_comp.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c >> index 5671752..5a5b6e4 100644 >> --- a/arch/x86/net/bpf_jit_comp.c >> +++ b/arch/x86/net/bpf_jit_comp.c >> @@ -289,7 +289,7 @@ void bpf_jit_compile(struct sk_filter *fp) >> EMIT2(0x24, K & 0xFF); /* and imm8,%al */ >> } else if (K >= 0xFFFF0000) { >> EMIT2(0x66, 0x25); /* and imm16,%ax */ >> - EMIT2(K, 2); >> + EMIT(K, 2); >> } else { >> EMIT1_off32(0x25, K); /* and imm32,%eax */ >> } > > Good catch, thanks ! > > Acked-by: Eric Dumazet Applied.