From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v2] net: bpf_jit: fix divide by 0 generation Date: Wed, 18 Jan 2012 16:04:42 -0500 (EST) Message-ID: <20120118.160442.2257803552295499142.davem@davemloft.net> References: <20120118155747.GA4991@linuxace.com> <1326902511.2316.29.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <1326907302.4910.11.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: kernel@linuxace.com, netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:40596 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932140Ab2ARVEq (ORCPT ); Wed, 18 Jan 2012 16:04:46 -0500 In-Reply-To: <1326907302.4910.11.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Wed, 18 Jan 2012 18:21:42 +0100 > Several problems fixed in this patch : > > 1) Target of the conditional jump in case a divide by 0 is performed > by a bpf is wrong. > > 2) Must 'generate' the full function prologue/epilogue at pass=0, > or else we can stop too early in pass=1 if the proglen doesnt change. > (if the increase of prologue/epilogue equals decrease of all > instructions length because some jumps are converted to near jumps) > > 3) Change the wrong length detection at the end of code generation to > issue a more explicit message, no need for a full stack trace. > > Reported-by: Phil Oester > Signed-off-by: Eric Dumazet Applied and queued up for -stable, thanks.