From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933079AbZLNV0S (ORCPT ); Mon, 14 Dec 2009 16:26:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932672AbZLNV0R (ORCPT ); Mon, 14 Dec 2009 16:26:17 -0500 Received: from gw1.cosmosbay.com ([212.99.114.194]:47395 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932662AbZLNV0Q (ORCPT ); Mon, 14 Dec 2009 16:26:16 -0500 Message-ID: <4B26AD65.1020004@gmail.com> Date: Mon, 14 Dec 2009 22:25:57 +0100 From: Eric Dumazet User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.9.1.5) Gecko/20091204 Thunderbird/3.0 MIME-Version: 1.0 To: Frederic Weisbecker CC: "David S. Miller" , Neil Horman , Netdev , LKML Subject: Re: packet_sendmsg_spkt sleeping from invalid context References: <20091214175211.GA5102@nowhere> <4B2690E7.4030303@gmail.com> <20091214205231.GB5037@nowhere> In-Reply-To: <20091214205231.GB5037@nowhere> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (gw1.cosmosbay.com [0.0.0.0]); Mon, 14 Dec 2009 22:25:59 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 14/12/2009 21:52, Frederic Weisbecker a écrit : > > I also wonder. Are you using PREEMPT_RCU ? Not at all :) But yes, this is illegal to do the memcpy_fromiovec() in rcu_read_lock() context. > That may explain why you haven't seen this issue because > might_sleep() doesn't see you are in a rcu read locked > section as preemption is not disabled, but it is illegal to > voluntarily sleep in such area (although it's fine with > preempt rcu) as doing so with non-prempt RCU config would barf. > > I'm trying a patch to handle that. As you want, I also have a patch testing right now :)