Date: Wed, 20 Jul 2005 13:30:15 +0200 From: =?ISO-8859-1?Q?Eirik_=D8verby?= <ltning@anduin.net> To: Robert Watson <rwatson@FreeBSD.org> Cc: stable@freebsd.org Subject: Re: Panic when logging out from serial console Message-ID: <CAC20955-5CC2-4456-A0DC-04A891414C2B@anduin.net> In-Reply-To: <20050410124013.W4310@fledge.watson.org> References: <20050410102753.d63hhe8vpcs8wsgg@anduin.net> <20050410124013.W4310@fledge.watson.org>
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On Apr 10, 2005, at 1:42 PM, Robert Watson wrote: > > On Sun, 10 Apr 2005 ltning@anduin.net wrote: > > >> warning: This report might be somewhat vague. For quite a while >> now I`ve been plagued with the problem that logging out from a >> serial console causes the box to panic. For a while I`ve been sure >> this was isolated to one of my boxen, because it`s been acting up >> in other ways as well, but today it happened on two other boxes >> too! And these boxes have been rock stable for the last two years. >> >> I`m running a fairly recent variation of RELENG-5 on all the >> boxes; one of them is amd64, the two others - including the one >> I`ve pasted from - are plain old p3 machines. They are all dual- >> CPU though. >> > > I've seen precisely this panic -- in fact, I saw it yesterday on a > RELENG_5 box, and under identical circumstances -- it looks like it > happens if a last process in a login session on a serial console > closes the tty, and then getty re-opens it while there's console > output coming from syslog. I was able to get a core dump, but > haven't made much headway on it yet. It looks like the tty > structure has been released -- the refcount on the tty is 0, and > the mutex pointers in the kqueue state have been cleared (hence the > null pointer dereference you see). Now, the question is why -- > I've added some debugging output to the local box I saw it on, and > will see if I can reproduce it. Did you ever manage to reproduce - or fix - this? I had a rather nasty incident recently due to this, even on a very recently updated 5.4. I sent a message to stable@ about it a few days ago, but have received no response. I personally think that this must be very very (very) bad - serial consoles shouldn't do this! ;) /Eirik > > Robert N M Watson > > >> >> I have no clue what I can do from here; has anyone seen this >> before? I can`t >> always reproduce it, but the risk is fairly high - around 33% I`d >> say. >> >> Anyone? >> >> Thanks for your attention, details below. >> >> Fatal trap 12: page fault while in kernel mode >> cpuid = 1; apic id = 00 >> fault virtual address = 0x1c >> fault code = supervisor write, page not present >> instruction pointer = 0x8:0xc0620b5f >> stack pointer = 0x10:0xdadbd988 >> frame pointer = 0x10:0xdadbd994 >> code segment = base 0x0, limit 0xfffff, type 0x1b >> = DPL 0, pres 1, def32 1, gran 1 >> processor eflags = interrupt enabled, resume, IOPL = 0 >> current process = 51999 (getty) >> trap number = 12 >> panic: page fault >> cpuid = 1 >> boot() called on cpu#0 >> Uptime: 66d11h24m50s >> >> >> >> /Eirik >> >> ---------------------------------------------------------------- >> This message was sent using IMP, the Internet Messaging Program. >> >> _______________________________________________ >> freebsd-stable@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-stable >> To unsubscribe, send any mail to "freebsd-stable- >> unsubscribe@freebsd.org" >> >> > >
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