From owner-freebsd-current Sat Oct 7 19:54:32 2000 Delivered-To: freebsd-current@freebsd.org Received: from field.videotron.net (field.videotron.net [205.151.222.108]) by hub.freebsd.org (Postfix) with ESMTP id 9A63E37B502; Sat, 7 Oct 2000 19:54:23 -0700 (PDT) Received: from modemcable213.3-201-24.mtl.mc.videotron.ca ([24.201.3.213]) by field.videotron.net (Sun Internet Mail Server sims.3.5.1999.12.14.10.29.p8) with ESMTP id <0G2300L0EC2M4O@field.videotron.net>; Sat, 7 Oct 2000 22:54:22 -0400 (EDT) Date: Sat, 07 Oct 2000 22:58:20 -0400 (EDT) From: Bosko Milekic Subject: Re: latest ahc panic, more data ... In-reply-to: X-Sender: bmilekic@jehovah.technokratis.com To: gibbs@freebsd.org Cc: freebsd-current@FreeBSD.ORG Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I've just been hit by one such problem on bootup. This is -current as of today, so I suspect it's the commits that went in the past two days. Basically, I tracked it down just enough to know that the problem is happening during a call to ahc_print_path() in aic7xxx.c, specifically for me, this happens during bootup in ahc_handle_scsiint() right after the second call to ahc_abort_scbs(). ahc_print_path() is called like this: ahc_print_path(ahc, scb); (why both ahc and scb are being passed, I have no idea, since ahc_print_path only actually makes use of scb). For the unaware, ahc_print_path() seems to only wrap a call to xpt_print_path() to which it passes scb->io_ctx->ccb_h.path as an argument, and in this case, scb->io_ctx happens to be NULL, so during its pass, a NULL pointer gets dereferenced and the page fault happens. The NULLing out of this is coming somewhere in ahc_handle_scsiint(), because some prior ahc_print_path()s (with the same arguments) are succeeding. I have not tried backing out the changes from the past two days and trying again, but this was not happening a week ago. So what's going on here? On Sat, 7 Oct 2000, Marc G. Fournier wrote: > > okay, have been watching the conversation going on in the committers list, > and am watching for any new commits that seem appropriate, but figure > adding a little bit of extra info as I come up with it might help? > > latest reboot had a bit more info then the last, and started with: > > ahc0:A:1: ahc_intr - referenced scb not valid during seqint 0x73 scb(147) > ach0: WARNING no command for scb 147 (cmdcmplt) > QOUTPOS=132 > > Marc G. Fournier scrappy@hub.org > Systems Administrator @ hub.org > scrappy@{postgresql|isc}.org ICQ#7615664 Bosko Milekic bmilekic@technokratis.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message