Commit 90091c36 authored by Misono Tomohiro's avatar Misono Tomohiro Committed by Kees Cook
Browse files

selftest/lkdtm: Skip stack-entropy test if lkdtm is not available 



Exit with return code 4 if lkdtm is not available like other tests
in order to properly skip the test.

Signed-off-by: default avatarMisono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210805101236.1140381-1-misono.tomohiro@jp.fujitsu.com
parent bc93a22a

tools/testing/selftests/lkdtm/stack-entropy.sh

+15 −1
Original line number Diff line number Diff line
@@ -4,13 +4,27 @@ 
# Measure kernel stack entropy by sampling via LKDTM's REPORT_STACK test.

set -e

samples="${1:-1000}"

TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT

KSELFTEST_SKIP_TEST=4



# Verify we have LKDTM available in the kernel.

if [ ! -r $TRIGGER ] ; then

	/sbin/modprobe -q lkdtm || true

	if [ ! -r $TRIGGER ] ; then

		echo "Cannot find $TRIGGER (missing CONFIG_LKDTM?)"

	else

		echo "Cannot write $TRIGGER (need to run as root?)"

	fi

	# Skip this test

	exit $KSELFTEST_SKIP_TEST

fi



# Capture dmesg continuously since it may fill up depending on sample size.

log=$(mktemp -t stack-entropy-XXXXXX)

dmesg --follow >"$log" & pid=$!

report=-1

for i in $(seq 1 $samples); do

        echo "REPORT_STACK" >/sys/kernel/debug/provoke-crash/DIRECT

        echo "REPORT_STACK" > $TRIGGER

	if [ -t 1 ]; then

		percent=$(( 100 * $i / $samples ))

		if [ "$percent" -ne "$report" ]; then