Re: [PATCH 21/24] selftests: memfd: return Kselftest Skip code for skipped tests

[Mike Kravetz]

On 05/04/2018 06:13 PM, Shuah Khan (Samsung OSG) wrote:
> When memfd test is skipped because of unmet dependencies and/or unsupported
> configuration, it returns non-zero value which is treated as a fail by the
> Kselftest framework. This leads to false negative result even when the test
> could not be run.
> 
> Change it to return kselftest skip code when a test gets skipped to
> clearly report that the test could not be run.
> 
> Added an explicit check for root user and return skip code.
> 
> Kselftest framework SKIP code is 4 and the framework prints appropriate
> messages to indicate that the test is skipped.
> 
> Signed-off-by: Shuah Khan (Samsung OSG) <shuah@xxxxxxxxxx>
> ---
>  tools/testing/selftests/memfd/run_tests.sh | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/memfd/run_tests.sh b/tools/testing/selftests/memfd/run_tests.sh
> index c2d41ed81b24..88dc206a69b7 100755
> --- a/tools/testing/selftests/memfd/run_tests.sh
> +++ b/tools/testing/selftests/memfd/run_tests.sh
> @@ -1,6 +1,14 @@
>  #!/bin/bash
>  # please run as root
>  
> +# Kselftest framework requirement - SKIP code is 4.
> +ksft_skip=4
> +
> +if [ $UID != 0 ]; then
> +	echo "Please run this test as root"
> +	exit $ksft_skip
> +fi
> +
>  #
>  # Normal tests requiring no special resources
>  #
> @@ -33,7 +41,7 @@ if [ -n "$freepgs" ] && [ $freepgs -lt $hpages_test ]; then
>  	echo $(( $hpages_needed + $nr_hugepgs )) > /proc/sys/vm/nr_hugepages
>  	if [ $? -ne 0 ]; then
>  		echo "Please run this test as root"
> -		exit 1
> +		exit $ksft_skip

We now KNOW that we are running as root because of the check above.  We
can delete this test, and rely on the later check to determine if the
number of huge pages was actually increased.

How about this instead (untested)?

Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
diff --git a/tools/testing/selftests/memfd/run_tests.sh b/tools/testing/selftests/memfd/run_tests.sh
index c2d41ed81b24..99a265a84e1d 100755
--- a/tools/testing/selftests/memfd/run_tests.sh
+++ b/tools/testing/selftests/memfd/run_tests.sh
@@ -1,6 +1,14 @@
 #!/bin/bash
 # please run as root
 
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+if [ $UID != 0 ]; then
+	echo "Please run this test as root"
+	exit $ksft_skip
+fi
+
 #
 # Normal tests requiring no special resources
 #
@@ -31,10 +39,6 @@ if [ -n "$freepgs" ] && [ $freepgs -lt $hpages_test ]; then
 
 	echo 3 > /proc/sys/vm/drop_caches
 	echo $(( $hpages_needed + $nr_hugepgs )) > /proc/sys/vm/nr_hugepages
-	if [ $? -ne 0 ]; then
-		echo "Please run this test as root"
-		exit 1
-	fi
 	while read name size unit; do
 		if [ "$name" = "HugePages_Free:" ]; then
 			freepgs=$size
@@ -53,7 +57,7 @@ if [ $freepgs -lt $hpages_test ]; then
 	fi
 	printf "Not enough huge pages available (%d < %d)\n" \
 		$freepgs $needpgs
-	exit 1
+	exit $ksft_skip
 fi
 
 #