From owner-freebsd-current@FreeBSD.ORG Tue Apr 16 03:05:27 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 96C66814; Tue, 16 Apr 2013 03:05:27 +0000 (UTC) (envelope-from gleb.kurtsou@gmail.com) Received: from mail-pb0-f51.google.com (mail-pb0-f51.google.com [209.85.160.51]) by mx1.freebsd.org (Postfix) with ESMTP id 6F41C91C; Tue, 16 Apr 2013 03:05:27 +0000 (UTC) Received: by mail-pb0-f51.google.com with SMTP id rr4so31553pbb.10 for ; Mon, 15 Apr 2013 20:05:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:date:from:to:cc:subject:message-id:references :mime-version:content-type:content-disposition:in-reply-to :user-agent; bh=Vr3C2Hxlv9TNfIBnLav/ssqz8Go3sVoLNBBJ+LVk3sY=; b=GmQBy4e9B2HGDqFyvBZnL0ya5tfd8e5RjUxobMa8cbdWn/+r5AXOeLlT/c8y4cv142 r70uJH+PXNRaKX5BHAg6rCd9HWBiAYBBgA3EtI/vvI1sF8WsftPCzv05nknsDs/SAlOU R9j4FVnMJSDWQeBBHM5bGbycxDOJtD+1TSSHgfYu4N5hPQXnjceOj/I0ORf/LRTP3ANW R5kiO72tfjkZUgsRq6Y+4KHKJaQd/mwkxqGUmUlBxvIGNmlduKh8EU7G9s0LCqkp3/7j 8lBm8r8ERyNXxhSCM74ZvYfdpf3dP4JcYDPfj+ak1kwfy8e/YKAJqkIy4ZvALCeQF+V0 icmA== X-Received: by 10.66.11.7 with SMTP id m7mr1121302pab.68.1366081526744; Mon, 15 Apr 2013 20:05:26 -0700 (PDT) Received: from localhost (c-67-160-248-74.hsd1.ca.comcast.net. [67.160.248.74]) by mx.google.com with ESMTPS id ra9sm595509pab.16.2013.04.15.20.05.25 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 15 Apr 2013 20:05:25 -0700 (PDT) Sender: Gleb Kurtsou Date: Mon, 15 Apr 2013 20:05:30 -0700 From: Gleb Kurtsou To: Pawel Jakub Dawidek Subject: Re: r248583 Kernel panic: negative refcount 0xfffffe0031b59168 Message-ID: <20130416030530.GA1274@reks> References: <20130414044314.GA1115@reks> <20130415083517.GB1410@garage.freebsd.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20130415083517.GB1410@garage.freebsd.pl> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: FreeBSD-current , Shawn Webb X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Apr 2013 03:05:27 -0000 On (15/04/2013 10:35), Pawel Jakub Dawidek wrote: > On Sat, Apr 13, 2013 at 09:43:14PM -0700, Gleb Kurtsou wrote: > > On (22/03/2013 11:51), Shawn Webb wrote: > > > Hey All, > > > > > > I'm not sure if this is a result of r248583 or a different commit, but I > > > hit a kernel panic when closing Chrome. I've linked to the info and > > > core.txt files below. If you need me to ship you the vmcore file, let me > > > know. It's 1.1GB in size. > > > > > > Other than the pasted files, I'm not too sure where to go from here. If > > > there's any other info you need, please let me know. I'm a newb at > > > submitting this kind of stuff. > > > > > > Paste of info file: http://ix.io/4Qo > > > Paste of core.txt file: http://ix.io/4Qp > > > > Shawn, did you find workaround for the problem? > > > > I've just upgraded to recent HEAD and see the same panic on closing > > chrome. Switching back to r247601 just before "Merge Capsicum overhaul" > > commit makes panic disappear. > > I did receive Shawn's report some time ago, I even installed Chromium to > try to reproduce it, but it didn't crash for me yet. I could send you chrome binary I'm using. It's a outdated chromium-22.0.1229.92. > If there are some easy, but reliable steps to reproduce it, like "open > this webpage in tab 1, then this webpage in tab 2, then close tab 1" > that would be great. This kernel coredump is not really useful, as we > this is legitimate case of decrementing reference counter. The problem > is that something decremented it earlier when it shouldn't or it wasn't > incremented somewhere. DTrace might be useful tool here if we could > instrument it to log backtrace of all increments and decrements done by > the Chromium processes. I'll try to reproduce it in vm.. which is not that easy because virtualbox kmod needs patching to work on month old CURRENT and there is no binary packages to install vm in the first place.