tests/int: add device access test

The test verifies if the device file can be queried using
'access(dev_name, F_OK)' when the permissions are set to 'rw'. The call
does not explicitly trigger read or write access but should succeed.

Signed-off-by: Vasiliy Ulyanov <vulyanov@suse.de>

tests/integration/dev.bats

@@ -59,7 +59,7 @@ function teardown() {
 @test "runc run [device cgroup allow rw char device]" {
 	requires root
 
-	update_config ' .linux.resources.devices = [{"allow": false, "access": "rwm"},{"allow": true, "type": "c", "major": 1, "minor": 11, "access": "rwm"}]
+	update_config ' .linux.resources.devices = [{"allow": false, "access": "rwm"},{"allow": true, "type": "c", "major": 1, "minor": 11, "access": "rw"}]
 			| .linux.devices = [{"path": "/dev/kmsg", "type": "c", "major": 1, "minor": 11}]
 			| .process.args |= ["sh"]
 			| .hostname = "myhostname"'
@@ -75,6 +75,12 @@ function teardown() {
 	# test read
 	runc exec test_allow_char sh -c 'head -n 1 /dev/kmsg'
 	[ "$status" -eq 0 ]
+
+	# test access
+	TEST_NAME="dev_access_test"
+	gcc -static -o "rootfs/bin/${TEST_NAME}" "${TESTDATA}/${TEST_NAME}.c"
+	runc exec test_allow_char sh -c "${TEST_NAME} /dev/kmsg"
+	[ "$status" -eq 0 ]
 }
 
 @test "runc run [device cgroup allow rm block device]" {

tests/integration/testdata/dev_access_test.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+	const char *dev_name = "/dev/kmsg";
+
+	if (argc > 1)
+		dev_name = argv[1];
+
+	if (access(dev_name, F_OK) < 0) {
+		perror(dev_name);
+		return 1;
+	}
+
+	return 0;
+}