selftests: netfilter: skip br_netfilter queue tests if kernel is tainted

These scripts fail if the kernel is tainted which leads to wrong test
failure reports in CI environments when an unrelated test triggers some
splat.

Check taint state at start of script and SKIP if its already dodgy.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

tools/testing/selftests/net/netfilter/br_netfilter.sh

@@ -13,6 +13,12 @@ source lib.sh
 
 checktool "nft --version" "run test without nft tool"
 
+read t < /proc/sys/kernel/tainted
+if [ "$t" -ne 0 ];then
+	echo SKIP: kernel is tainted
+	exit $ksft_skip
+fi
+
 cleanup() {
 	cleanup_all_ns
 }
@@ -165,6 +171,7 @@ if [ "$t" -eq 0 ];then
 	echo PASS: kernel not tainted
 else
 	echo ERROR: kernel is tainted
+	dmesg
 	ret=1
 fi
 

tools/testing/selftests/net/netfilter/br_netfilter_queue.sh

@@ -4,6 +4,12 @@ source lib.sh
 
 checktool "nft --version" "run test without nft tool"
 
+read t < /proc/sys/kernel/tainted
+if [ "$t" -ne 0 ];then
+	echo SKIP: kernel is tainted
+	exit $ksft_skip
+fi
+
 cleanup() {
 	cleanup_all_ns
 }
@@ -72,6 +78,7 @@ if [ "$t" -eq 0 ];then
 	echo PASS: kernel not tainted
 else
 	echo ERROR: kernel is tainted
+	dmesg
 	exit 1
 fi
 

tools/testing/selftests/net/netfilter/nft_queue.sh

@@ -593,6 +593,7 @@ EOF
 		echo "PASS: queue program exiting while packets queued"
 	else
 		echo "TAINT: queue program exiting while packets queued"
+		dmesg
 		ret=1
 	fi
 }