Re: [PATCH v4] kselftests/damon: add support for cases where debugfs cannot be read

[Shuah Khan]

On 6/25/22 2:03 PM, SeongJae Park wrote:
> Hi Gautam,
>
> On Sun, 26 Jun 2022 01:22:45 +0530 Gautam <gautammenghani201@xxxxxxxxx> wrote:
>
> > The kernel is in lockdown mode when secureboot is enabled and hence
> > debugfs cannot be used. Add support for this and other general cases
> > where debugfs cannot be read and communicate the same to the user before
> > running tests.
> >
> > Signed-off-by: Gautam <gautammenghani201@xxxxxxxxx>
>
> Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
>
>
> Thanks,
> SJ
>
> > ---
> > Changes in v2:
> > 1. Modify the error message to account for general cases.
> > 2. Change the return code so that the test is skipped.
> >
> > Changes in v3:
> > 1. Change the name of variable holding the error message.
> >
> > Changes in v4:
> > 1. Correct the mode of the source file.
> >
> >   tools/testing/selftests/damon/_chk_dependency.sh | 10 ++++++++++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/tools/testing/selftests/damon/_chk_dependency.sh b/tools/testing/selftests/damon/_chk_dependency.sh
> > index 0189db81550b..0328ac0b5a5e 100644
> > --- a/tools/testing/selftests/damon/_chk_dependency.sh
> > +++ b/tools/testing/selftests/damon/_chk_dependency.sh
> > @@ -26,3 +26,13 @@ do
> >   		exit 1
> >   	fi
> >   done
> > +
> > +permission_error="Operation not permitted"
> > +for f in attrs target_ids monitor_on
> > +do
> > +	status=$( cat "$DBGFS/$f" 2>&1 )
> > +	if [ "${status#*$permission_error}" != "$status" ]; then
> > +		echo "Permission for reading $DBGFS/$f denied; maybe secureboot enabled?"

btw - does this run as a regular user or does it need root privilege?
If so add a test for that and skip with a message.
> > +		exit $ksft_skip
> > +	fi
> > +done
> > --
> > 2.36.1
thanks,
-- Shuah