From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ren Mingxin Date: Wed, 11 Apr 2012 09:09:52 +0000 Subject: Re: [RFC PATCH] virtio_blk: Checking "private_data" to avoid kernel panic when hotplugging Message-Id: <4F854A60.7010704@cn.fujitsu.com> List-Id: References: <4F728831.2090406@cn.fujitsu.com> <20120409075318.GB27771@redhat.com> <4F84F7BC.102@cn.fujitsu.com> <20120411083608.GC8562@redhat.com> In-Reply-To: <20120411083608.GC8562@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Michael S. Tsirkin" Cc: Rusty Russell , Kay Sievers , Tokunaga Kei , LKML , UDEV On 04/11/2012 04:36 PM, Michael S. Tsirkin wrote: > On Wed, Apr 11, 2012 at 11:17:16AM +0800, Ren Mingxin wrote: >> On 04/09/2012 03:53 PM, Michael S. Tsirkin wrote: >> >>> There's a chance you are hitting a race fixed by >>> 4678d6f970c2f7c0cbfefc0cc666432d153b321b. >>> >>> If it's still not fixed it might make sense to enable slab debugging - >>> we might have a use after free here. >>> >> I don't think the below commit has fixed this panic issue, for it is >> included >> in my last test environment(3.3-rc7). >> 4678d6f970c2f7c0cbfefc0cc666432d153b321b >> >> Now, I'd find which commit makes sense. > Great, thanks very much. I do suggest slab debugging if > the race reproduces for you with it enabled - reducing > the chance random struct rearrangements hide the bug. > Much appreciated for suggesting :-) I'll try it to locate the commit and backport it into rhel. -- Thanks, Ren