[Fwd: Re: kern/118258 sysctl causing panics on 7.0-xxx]
John Baldwin
jhb at freebsd.org
Fri Jan 4 09:58:37 PST 2008
On Friday 04 January 2008 05:19:28 am Tai-hwa Liang wrote:
> On Thu, 3 Jan 2008, John Baldwin wrote:
> > On Thursday 29 November 2007 10:53:32 pm Tai-hwa Liang wrote:
> >> On Wed, 28 Nov 2007, Remko Lodder wrote:
> >>> Hello,
> >>>
> >>> So as per Jeff's information, can someone from the -current
> >>> list either contact jeff or try to resolve the problems
> >>> mentioned? :)
> >>
> >> This is a longstanding bug which also exists in RELENG_6. It turns
out
> >> that 'sysctl kern.ttys' after a terminal device is removed could trigger
> >> this panic reliably. For example, do 'sysctl kern.ttys' multiple times
> >> after detaching an USB serial-to-rs232 cable or a PCMCIA modem card.
> >>
> >> Alternatively, following script would demo the panic if you don't have
> >> a physically removable terminal device:
> >>
> >> #!/bin/sh
> >> #
> >> # Warning! Running this script as root will panic your CURRENT box...
> >> #
> >> while true; do
> >> kldload dcons
> >> kldunload dcons
> >> ls /dev
> >> sysctl kern.ttys
> >> sleep 1
> >> done
> >>
> >> This seems to be a race between devfs and destroy_dev(), Cc'ing kib@
> >> since he probably has more clues in this area.
> >
> > Try this patch. Also available at
> > http://www.FreeBSD.org/~jhb/patches/ttys_sysctl.patch
>
> With this patch, -CURRENT no longer boots and panics as follows:
Fixed, was missing an unlock at the bottom of the loop. Patch is updated at
the same URL.
--
John Baldwin
More information about the freebsd-current
mailing list