linux-kernel - Re: [PATCH] selftests/kselftest/runner/run_one(): Allow running non-executable files

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Date:   Tue, 10 Aug 2021 16:43:57 +0000
From:   SeongJae Park <sj38.park@...il.com>
To:     Greg KH <gregkh@...uxfoundation.org>
Cc:     SeongJae Park <sj38.park@...il.com>, shuah@...nel.org,
        linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org,
        akpm@...ux-foundation.org, SeongJae Park <sjpark@...zon.de>
Subject: Re: [PATCH] selftests/kselftest/runner/run_one(): Allow running non-executable files

From: SeongJae Park <sjpark@...zon.de>

On Tue, 10 Aug 2021 17:07:28 +0200 Greg KH <gregkh@...uxfoundation.org> wrote:

> On Tue, Aug 10, 2021 at 02:04:59PM +0000, SeongJae Park wrote:
> > From: SeongJae Park <sjpark@...zon.de>
> > 
> > When running a test program, 'run_one()' checks if the program has the
> > execution permission and fails if it doesn't.  However, it's easy to
> > mistakenly missing the permission, as some common tools like 'diff'
> > don't support the permission change well[1].  Compared to that, making
> > mistakes in the test program's path would only rare, as those are
> > explicitly listed in 'TEST_PROGS'.  Therefore, it might make more sense
> > to resolve the situation on our own and run the program.
> > 
> > For the reason, this commit makes the test program runner function to
> > still print the warning message but run the program after giving the
> > execution permission in the case.  To make nothing corrupted, it also
> > restores the permission after running it.
> > 
> > [1] https://lore.kernel.org/mm-commits/YRJisBs9AunccCD4@kroah.com/
> > 
> > Suggested-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> > Signed-off-by: SeongJae Park <sjpark@...zon.de>
> > ---
> >  tools/testing/selftests/kselftest/runner.sh | 18 +++++++++++-------
> >  1 file changed, 11 insertions(+), 7 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/kselftest/runner.sh b/tools/testing/selftests/kselftest/runner.sh
> > index cc9c846585f0..2eb31e945709 100644
> > --- a/tools/testing/selftests/kselftest/runner.sh
> > +++ b/tools/testing/selftests/kselftest/runner.sh
> > @@ -65,15 +65,16 @@ run_one()
> >  
> >  	TEST_HDR_MSG="selftests: $DIR: $BASENAME_TEST"
> >  	echo "# $TEST_HDR_MSG"
> > -	if [ ! -x "$TEST" ]; then
> > -		echo -n "# Warning: file $TEST is "
> > -		if [ ! -e "$TEST" ]; then
> > -			echo "missing!"
> > -		else
> > -			echo "not executable, correct this."
> > -		fi
> > +	if [ ! -e "$TEST" ]; then
> > +		echo "# Warning: file $TEST is missing!"
> >  		echo "not ok $test_num $TEST_HDR_MSG"
> >  	else
> > +		permission_added="false"
> > +		if [ ! -x "$TEST" ]; then
> > +			echo "# Warning: file $TEST is not executable"
> > +			chmod u+x "$TEST"
> > +			permission_added="true"
> 
> No, why would you change the permission of a test?  What happens if this
> is on a read-only filesystem?  You should not be modifying it as it will
> end up causing changes when not needed.

Agreed.  I will parse the shebang line and use the interpreter explicitly in
the next spin.


Thanks,
SeongJae Park

> 
> thanks,
> 
> greg k-h