added prints and close device

code/Makefile

@@ -1,8 +1,8 @@
 obj-m += lkm.o
 
-all: module
+all: module leak
 
-run: module leak.c
+run: leak
 	./leak
 
 module:

code/leak.c

@@ -3,8 +3,11 @@
 int
 main(void)
 {
-	fopen("/dev/lkm", "r+");
+	printf("main: start\n");
+	FILE *device = fopen("/dev/lkm", "r+");
 
-	for (;;)
+	printf("main: fopen: %p\n", device);
-		;
+
+	fclose(device);
+	printf("main: done\n");
 }