From owner-freebsd-current Tue Mar 26 14:43:11 2002 Delivered-To: freebsd-current@freebsd.org Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by hub.freebsd.org (Postfix) with ESMTP id C43F537B400 for ; Tue, 26 Mar 2002 14:43:07 -0800 (PST) Received: by elvis.mu.org (Postfix, from userid 1192) id 9533DAE163; Tue, 26 Mar 2002 14:43:07 -0800 (PST) Date: Tue, 26 Mar 2002 14:43:07 -0800 From: Alfred Perlstein To: Kris Kennaway Cc: current@FreeBSD.org Subject: Re: Lock order reversals in sys_pipe.c Message-ID: <20020326224307.GE93885@elvis.mu.org> References: <20020324142632.A60767@xor.obsecurity.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020324142632.A60767@xor.obsecurity.org> User-Agent: Mutt/1.3.27i Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Kris Kennaway [020324 14:26] wrote: > The bento cluster is now running with WITNESS enabled to try and track > down some odd UMA lock corruption panics. Instead, it found the > following lock order reversal in sys_pipe.c overnight: > > Mar 24 07:31:44 gohan17 kernel: lock order reversal > Mar 24 07:31:44 gohan17 kernel: 1st 0xcf51aa80 pipe mutex @ /local0/scratch/usr/src/sys/kern/sys_pipe.c:450 > Mar 24 07:31:44 gohan17 kernel: 2nd 0xcf88dadc process lock @ /local0/scratch/usr/src/sys/kern/kern_sig.c:2093 > Mar 24 07:32:12 gohan10 kernel: lock order reversal > Mar 24 07:32:12 gohan10 kernel: 1st 0xd9a29dc0 pipe mutex @ /local0/scratch/usr/src/sys/kern/sys_pipe.c:450 > Mar 24 07:32:12 gohan10 kernel: 2nd 0xd961addc process lock @ /local0/scratch/usr/src/sys/kern/kern_sig.c:2093 > Mar 24 07:32:57 gohan12 kernel: lock order reversal > Mar 24 07:32:57 gohan12 kernel: 1st 0xd9423080 pipe mutex @ /local0/scratch/usr/src/sys/kern/sys_pipe.c:450 > Mar 24 07:32:57 gohan12 kernel: 2nd 0xdaa704dc process lock @ /local0/scratch/usr/src/sys/kern/kern_sig.c:2093 > Mar 24 09:02:29 gohan13 kernel: lock order reversal > Mar 24 09:02:29 gohan13 kernel: 1st 0xd99d6500 pipe mutex @ /local0/scratch/usr/src/sys/kern/sys_pipe.c:450 > Mar 24 09:02:29 gohan13 kernel: 2nd 0xd971cddc process lock @ /local0/scratch/usr/src/sys/kern/kern_sig.c:2093 > > Those source references are from a -current kernel from last night. Are you %100 on that? How did you get this to happen? I can see where I hold the pipe lock, then try to get a proc lock, but not the other way around... Any ideas? -- -Alfred Perlstein [alfred@freebsd.org] 'Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom.' Tax deductible donations for FreeBSD: http://www.freebsdfoundation.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message