From owner-freebsd-sparc64@FreeBSD.ORG Fri Jan 27 14:01:32 2012 Return-Path: Delivered-To: freebsd-sparc64@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6C4341065673 for ; Fri, 27 Jan 2012 14:01:32 +0000 (UTC) (envelope-from marius@alchemy.franken.de) Received: from alchemy.franken.de (alchemy.franken.de [194.94.249.214]) by mx1.freebsd.org (Postfix) with ESMTP id 002FD8FC0C for ; Fri, 27 Jan 2012 14:01:31 +0000 (UTC) Received: from alchemy.franken.de (localhost [127.0.0.1]) by alchemy.franken.de (8.14.4/8.14.4/ALCHEMY.FRANKEN.DE) with ESMTP id q0RE1UKP032384; Fri, 27 Jan 2012 15:01:30 +0100 (CET) (envelope-from marius@alchemy.franken.de) Received: (from marius@localhost) by alchemy.franken.de (8.14.4/8.14.4/Submit) id q0RE1TMh032383; Fri, 27 Jan 2012 15:01:30 +0100 (CET) (envelope-from marius) Date: Fri, 27 Jan 2012 15:01:29 +0100 From: Marius Strobl To: Denny Schierz Message-ID: <20120127140129.GA32328@alchemy.franken.de> References: <5C638638-3D1A-417E-A574-9BCE51E08C59@4lin.net> <20120124202111.GB7731@alchemy.franken.de> <431CCA8C-2E5E-43BC-89EE-7F06CF8E8E8D@4lin.net> <20120125150054.GA15762@alchemy.franken.de> <926170B2-9DF2-4DCC-9643-E66E6504B185@4lin.net> <4F202586.5010808@xs4all.nl> <6F47ED26-0604-46C9-BA6F-0802D917D4AE@4lin.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6F47ED26-0604-46C9-BA6F-0802D917D4AE@4lin.net> User-Agent: Mutt/1.4.2.3i Cc: freebsd-sparc64@freebsd.org Subject: Re: Howto debug Kernel problems ? (jail -r -> freeze) X-BeenThere: freebsd-sparc64@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the Sparc List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Jan 2012 14:01:32 -0000 On Thu, Jan 26, 2012 at 12:55:02PM +0100, Denny Schierz wrote: > hi, > > Am 25.01.2012 um 16:53 schrieb Michiel Boland: > > > sysctl debug.kdb.alt_break_to_debugger=1 > > great :-), it works (until ... ) > > I did the test again: > > /etc/rc.d/jail onestart > /etc/rc.d/jail/onestop > > jls ... > > jail -r 1 > > The command hangs, the server doesn't accept ssh connections anymore, but ping works. But only until I make something like "telnet localhost 22" to check, if SSH accept from localhost .. .... FREEZE .... > > back to ALOM, send break ... connect ... nothing. -> Reset > >From your email it's once again not clear whether the alternate break sequence works or not when the the machine hangs. If it doesn't the only thing I currently can think of is to resort to printf(9)-debugging starting at sys_jail_remove() in kern_jail.c in order to determine where the hang occurs. This somewhat smells like the kernel trying to directly use and userland address and not going through copy{in,out}(9), which would match both the symptoms of a hang and it just working anyway on x86. On a quick glance at kern_jail.c I can't spot an obvious issue. From your previous emails and the mailing list reference you gave it's also not clear whether you are using some kernel patch which might introduce such a bug though. Marius