6.2-RELEASE panic when blanking CD-RW media

Fabian Keil freebsd-listen at fabiankeil.de
Thu Feb 22 11:37:21 UTC 2007


"Petr Holub" <hopet at ics.muni.cz> wrote:

> I've encountered a deterministic kernel panic when
> blanking one specific CD-RW media using cdrecord.

> The kernel panic details follow and dmesg is at the end of this
> email. Though I understand there's something wrong with the media,
> I think it shouldn't panic the kernel either.

> # kgdb /boot/kernel/kernel vmcore.9

> (kgdb) bt
> #0  0xc067262e in doadump ()
> #1  0xc0672afe in boot ()
> #2  0xc0672d94 in panic ()
> #3  0xc0885a04 in trap_fatal ()
> #4  0xc088576b in trap_pfault ()
> #5  0xc08853a9 in trap ()
> #6  0xc0873a7a in calltrap ()
> #7  0xc04e5e2e in acd_geom_detach ()
> #8  0xc06388f9 in one_event ()
> #9  0xc06389d1 in g_run_events ()
> #10 0xc0639de5 in g_event_procbody ()
> #11 0xc065cd34 in fork_exit ()
> #12 0xc0873adc in fork_trampoline ()
> (kgdb) x 0xc067262e
> 0xc04e5e2e <acd_geom_detach+18>:	0x03b0b0ff
> (kgdb) q

You could give the following patch a try: 
http://www.fabiankeil.de/sourcecode/freebsd/atapi-cd.c.patch

It prevents a panic if a disc drive gets "lost"
without FreeBSD noticing it (for example because
the firmware is buggy).

See:
http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/99017
for details.

Note that the patch simply prevents the panic,
your drive will probably still be "lost" until
you reboot.

Fabian
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 187 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20070222/a20befd1/signature.pgp


More information about the freebsd-stable mailing list