Date: Fri, 23 Mar 2001 14:00:03 -0800 (PST) From: Peter Wemm <peter@netplex.com.au> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/26034: kldload() panics if error code is returned from <module_name>_load(). Message-ID: <200103232200.f2NM03q36535@freefall.freebsd.org>
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The following reply was made to PR kern/26034; it has been noted by GNATS.
From: Peter Wemm <peter@netplex.com.au>
To: jtrainor@fastekintl.com
Cc: freebsd-gnats-submit@FreeBSD.ORG
Subject: Re: kern/26034: kldload() panics if error code is returned from <module_name>_load().
Date: Fri, 23 Mar 2001 13:50:52 -0800
jtrainor@fastekintl.com wrote:
>
> >Number: 26034
> >Category: kern
> >Synopsis: kldload() panics if error code is returned from <module_name
>_load().
> >Description:
> panic trap 12 (page fault) in kldload while attempting to return an error fro
m <module_name>_load. If I set the return value prior to entering the case
statement, proper behavior is observed. If I set the return value inside
the case statement, panic occurs. See code below.
This is because if you fail on the MOD_LOAD case, the linker calls all the
MOD_UNLOADs for the modules in the kld file. In your case, you
are calling "destroy_dev(sdev);" on MOD_UNLOAD, which is panicing since
sdev is uninitialized. This is actually a bug in your module due to the
existing module load/unload semantics. Remember, there can be more than
one module inside a .ko kld file.
One could argue that a MOD_UNLOAD event should be skipped for modules that
have failed to load successfully.. I think this change needs to happen.
Cheers,
-Peter
--
Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au
"All of this is for nothing if we don't go to the stars" - JMS/B5
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