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From:   SeongJae Park <sj38.park@gmail.com>
To:     Shuah Khan <skhan@linuxfoundation.org>
Cc:     SeongJae Park <sj@kernel.org>,
        Gautam <gautammenghani201@gmail.com>, shuah@kernel.org,
        damon@lists.linux.dev, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] kselftests/damon: add support for cases where debugfs cannot be read
Date:   Mon, 27 Jun 2022 18:57:04 +0000
Message-Id: <20220627185704.58902-1-sj38.park@gmail.com>
In-Reply-To: <7d6b7de6-4609-e6ca-0a88-1f9799c70769@linuxfoundation.org>
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From: SeongJae Park <sj@kernel.org>

Hi Shuah,

On Mon, 27 Jun 2022 11:00:18 -0600 Shuah Khan <skhan@linuxfoundation.org> wrote:

[...]
> >> --- 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.

It needs the root permission, and does the check at the beginning[1].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/selftests/damon/_chk_dependency.sh?h=v5.19-rc4#n9


Thanks,
SJ

> >> +		exit $ksft_skip
> >> +	fi
> >> +done
> >> -- 
> >> 2.36.1
> >
> thanks,
> -- Shuah