From owner-freebsd-current@FreeBSD.ORG Mon May 18 16:18:55 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EDCCA106566B for ; Mon, 18 May 2009 16:18:55 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from ch-smtp01.sth.basefarm.net (ch-smtp01.sth.basefarm.net [80.76.149.212]) by mx1.freebsd.org (Postfix) with ESMTP id A6C658FC15 for ; Mon, 18 May 2009 16:18:55 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from c83-253-252-234.bredband.comhem.se ([83.253.252.234]:33088 helo=mx.exscape.org) by ch-smtp01.sth.basefarm.net with esmtp (Exim 4.69) (envelope-from ) id 1M65Y5-00052e-5x; Mon, 18 May 2009 18:18:48 +0200 Received: from [192.168.1.5] (macbookpro [192.168.1.5]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mx.exscape.org (Postfix) with ESMTPSA id BF14A3A611; Mon, 18 May 2009 18:18:38 +0200 (CEST) Message-Id: From: Thomas Backman To: Wesley Shields In-Reply-To: <20090518161148.GA56646@atarininja.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v935.3) Date: Mon, 18 May 2009 18:18:38 +0200 References: <949B5884-5303-4EFF-AC7D-293640FFA012@exscape.org> <20090518161148.GA56646@atarininja.org> X-Mailer: Apple Mail (2.935.3) X-Originating-IP: 83.253.252.234 X-Scan-Result: No virus found in message 1M65Y5-00052e-5x. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1M65Y5-00052e-5x b95cf2d2aa4db49689fcb89f034cc292 Cc: freebsd-current@freebsd.org Subject: Re: DTrace panic while probing syscall::open (and possibly many others) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 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: Mon, 18 May 2009 16:18:56 -0000 On May 18, 2009, at 06:11 PM, Wesley Shields wrote: > On Wed, May 13, 2009 at 03:19:05PM +0200, Thomas Backman wrote: >> OK, so I first posted a thread on the forums about this in 7.2- >> RELEASE: >> http://forums.freebsd.org/showthread.php?t=3834 >> Then filed a PR, kern/134408: >> http://www.freebsd.org/cgi/query-pr.cgi?pr=134408 >> >> The very same bug remains in 8-CURRENT/amd64 as of May 13, ~10(am) >> GMT+2. >> >> Steps to reproduce: >> 1) Build DTrace capable kernel (I followed the wiki DTrace >> instructions) >> 2) Reboot; kldload dtraceall >> 3) dtrace -n 'syscall::open:entry { self->path = arg0; } >> syscall::open:return { printf("%s\n", copyinstr(self->path)); }' >> 4) Crash. >> >> Backtrace: >> [...] > > It's not the probe that is the problem. I suspect it's the copyinstr. > >> Same panic on two computers (a "real" one, A64 3200+, nForce4, 2GB >> RAM; >> and a Macbook Pro C2D running VMware Fusion). Same panic in 7.2 and >> 8.0. > > I can easily reproduce this also. > > -- WXS Yup, it's copyinstr() crashing. It works if you simply replace printf(...) with printf("file opened\n") which doesn't copy anything in, and the backtrace seems (even to me ;) to point towards it. Regards, Thomas