From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752347AbbIQVc1 (ORCPT ); Thu, 17 Sep 2015 17:32:27 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:32930 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751339AbbIQVc0 (ORCPT ); Thu, 17 Sep 2015 17:32:26 -0400 Date: Thu, 17 Sep 2015 17:32:13 -0400 From: Sowmini Varadhan To: Andrew Morton Cc: linux-kernel@vger.kernel.org, benh@kernel.crashing.org, linux@roeck-us.net, davem@davemloft.net Subject: Re: [PATCH] iommu-common: Do not try to deref a null iommu->lazy_flush() pointer when n < pool->hint Message-ID: <20150917213213.GE20745@oracle.com> References: <20150917015043.GC13020@oracle.com> <20150917142644.a7a3c272be10280028c5ad3a@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150917142644.a7a3c272be10280028c5ad3a@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (09/17/15 14:26), Andrew Morton wrote: > Patch looks good. > > But I don't know which kernel versions need the fix. So, when fixing a > bug please always describe the end-user visible effects of that bug. > Under what circumstances did your kernel crash? > I had a sparc kernel that was crashing when I was trying to process some very large perf.data files- the crash happens when the scsi driver calls into dma_4v_map_sg and thus the iommu_tbl_range_alloc(). Do you need me to respin the patch with the above info in the commit id? --Sowmini