[PATCH] selftests: livepatch: Fix it to do root uid check and skip

[Shuah Khan]

livepatch test configures the system and debug environment to run
tests. Some of these actions fail without root access and test
dumps several permission denied messages before it exits.

Fix it to check root uid and exit with skip code instead.

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
 tools/testing/selftests/livepatch/functions.sh | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
index 31eb09e38729..014b587692f0 100644
--- a/tools/testing/selftests/livepatch/functions.sh
+++ b/tools/testing/selftests/livepatch/functions.sh
@@ -7,6 +7,9 @@
 MAX_RETRIES=600
 RETRY_INTERVAL=".1"	# seconds
 
+# Kselftest framework requirement - SKIP code is 4
+ksft_skip=4
+
 # log(msg) - write message to kernel log
 #	msg - insightful words
 function log() {
@@ -18,7 +21,16 @@ function log() {
 function skip() {
 	log "SKIP: $1"
 	echo "SKIP: $1" >&2
-	exit 4
+	exit $ksft_skip
+}
+
+# root test
+function is_root() {
+	uid=$(id -u)
+	if [ $uid -ne 0 ]; then
+		echo "skip all tests: must be run as root" >&2
+		exit $ksft_skip
+	fi
 }
 
 # die(msg) - game over, man
@@ -45,6 +57,7 @@ function pop_config() {
 }
 
 function set_dynamic_debug() {
+	is_root
         cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
 		file kernel/livepatch/* +p
 		func klp_try_switch_task -p
@@ -62,6 +75,7 @@ function set_ftrace_enabled() {
 #		 for verbose livepatching output and turn on
 #		 the ftrace_enabled sysctl.
 function setup_config() {
+	is_root
 	push_config
 	set_dynamic_debug
 	set_ftrace_enabled 1
-- 
2.20.1