Re: [PATCH, RFC] xfstests: fail test if it causes a kernel taint

[Dave Chinner <david@fromorbit.com>]

On Mon, May 13, 2013 at 09:00:45PM -0500, Eric Sandeen wrote:
> On 5/13/13 8:15 PM, Dave Chinner wrote:
> > On Mon, May 13, 2013 at 04:55:18PM -0500, Eric Sandeen wrote:
> >> This should, in theory, fail a test if it introduces one of
> >> a handful of "serious" kernel taints.  I mask on a few taint
> >> values because using an out of tree module or a non-GPL module
> >> should never fail a test, for example.
> >>
> >> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> > 
> > I like the idea - it should catch lockdep failures and other such
> > problems.
> > 
> >> ---
> >>
> >> diff --git a/check b/check
> >> index a79747e..a9cac4e 100755
> >> --- a/check
> >> +++ b/check
> >> @@ -446,6 +445,11 @@ do
> >>  	fi
> >>  	rm -f core $seqres.notrun
> >>  
> >> +	if [ "$HOSTOS" == "Linux" ]; then
> >> +		tainted=`sysctl -n kernel.tainted`
> >> +		let "tainted &= $TAINT_FAIL"
> >> +	fi
> >> +
> >>  	start=`_wallclock`
> >>  	$timestamp && echo -n "	["`date "+%T"`"]"
> >>  	[ ! -x $seq ] && chmod u+x $seq # ensure we can run it
> >> @@ -507,6 +511,19 @@ do
> >>  			 "entire diff)"
> >>  		    err=true
> >>  		fi
> >> +
> >> +		# See if this run tainted the kernel due to oops, etc
> >> +		if [ "$HOSTOS" == "Linux" ]
> >> +		then
> >> +			tainted2=`sysctl -n kernel.tainted`
> >> +			let "tainted2 &= $TAINT_FAIL"
> >> +			if [ "$tainted" != "$tainted2" ]
> >> +			then
> >> +				echo " Kernel taint changed from $tainted to $tainted2."
> >> +				echo " See dmesg for details."
> >> +				err=true
> >> +			fi
> > 
> > Should we dump the last 100 lines of dmesg into the output file
> > here? And then rely on the golden image match failing to fail the
> > test?
> 
> Or into $seq.full . .  I dunno.  It's hard to know how much dmesg you'd need to get the right bits.
> 
> Dumping all of it into $seq.full might be best; it only trips when it's a new taint, so won't
> fire for every test.

Only problem with $seqres.full is that it is internal to the test
and so many tests will not remove one that is there before the test
starts. Hence you'll get growing files the never get removed from
repeated failures. Even just dumping the above error message into
the output file would be sufficient, I think, as the 10 line diff
output will state it pretty clearly as the first difference....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

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