From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755305AbaIPU30 (ORCPT ); Tue, 16 Sep 2014 16:29:26 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:57954 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755027AbaIPU3Z (ORCPT ); Tue, 16 Sep 2014 16:29:25 -0400 Date: Tue, 16 Sep 2014 16:29:23 -0400 (EDT) Message-Id: <20140916.162923.605101746131407931.davem@davemloft.net> To: nhorman@tuxdriver.com Cc: mroos@linux.ee, klassert@mathematik.tu-chemnitz.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: bisected regression: 3c59x corrupts packets in 3.17-rc5 From: David Miller In-Reply-To: <20140916101704.GA3792@hmsreliant.think-freely.org> References: <20140916101704.GA3792@hmsreliant.think-freely.org> X-Mailer: Mew version 6.6 on Emacs 24.3 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Tue, 16 Sep 2014 13:29:24 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Neil Horman Date: Tue, 16 Sep 2014 06:17:04 -0400 > I'm guessing the above change has uncovered another bug, Neil, read your patch carefully, I think it added the bug. The ->page_offset of the frag gets applied two times. skb_dma_map_frag() already takes frag->page_offset into consideration, you then pass it in as the 'offset' argument and it then gets added to itself to compute th final offset.