i386/167340: cdcontrol: play nonexistent audio track causes kernel trap 12

[Remko Lodder]

The following reply was made to PR i386/167340; it has been noted by GNATS.

From: Remko Lodder <remko at elvandar.org>
To: Michael L. Semon <mlsemon35 at gmail.com>
Cc: freebsd-gnats-submit at FreeBSD.org
Subject: Re: i386/167340: cdcontrol: play nonexistent audio track causes kernel trap 12
Date: Fri, 27 Apr 2012 08:14:40 +0200

 >>=20
 >>=20
 > Suppose I have an audio CD with 15 tracks on it.  To issue commands =
 like "cdcontrol 16" or "cdcontrol 32" or "cdcontrol 'play 19'" causes =
 FreeBSD to stop immediately.  Not copying the entire screen by hand, I =
 boil it down to this:
 >=20
 > kernel trap 12 with interrupts disabled
 >=20
 > Fatal trap 12: page fault while in kernel mode
 >=20
 > fault virtual address =3D 0x2c
 > fault code =3D  supervisor write, page not present
 >=20
 > This PC is a boat anchor (Pentium III/500, ATAPI CD-ROM, all older ATA =
 drives of the non-serial variety), so all I ask is that you try to =
 duplicate the problem on your modern hardware.  If you can't reproduce =
 the problem, I'll strive to be really careful when using cdcontrol.
 >=20
 > Going back to FreeBSD 6.2 or 6.3, I've never had a crash of any kind =
 from cdcontrol until now...and I've made many, many data entry mistakes =
 with cdcontrol.
 >>=20
 
 Hello Michael,
 
 It's difficult to reproduce such a thing when it can depend on many many =
 different factors (motherboard vendor, cd drive vendor, cpu vendor etc).
 What would be more reasonable is that you try to get a kernel dump, =
 which we can use to look into the problem you are mentioning, this =
 kernel
 dump includes information about what triggered the error, the code path =
 and the like.
 
 You can find more information here: =
 http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html
 
 If you cannot do this, we need to suspend the ticket, till someone can =
 reproduce this and deliver the required information
 so that the developers can have a look at this :)
 
 Thank you very much for making FreeBSD better!
 
 
 --=20
 /"\   With kind regards,			| remko at elvandar.org
 \ /   Remko Lodder			| remko at FreeBSD.org
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