Problem building simple Linux kernel module.

/* Module source file 'crash1.c'. */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>

static int hi(void)
{
     printk(KERN_INFO "crash1 module being loaded.\n");
     return 0;
}

static void bye(void)
{
     printk(KERN_INFO "crash1 module being unloaded.\n");
}

module_init(hi);
module_exit(bye);

MODULE_AUTHOR("Robert P. J. Day, http://crashcourse.ca");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Doing a whole lot of nothing.");

ifeq ($(KERNELRELEASE),)

KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)

.PHONY: build clean

build:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules

clean:
    rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c

else    

$(info Building with KERNELRELEASE = ${KERNELRELEASE})
obj-m :=    crash1.o

endif

make -C /lib/modules/3.5.0-17-generic/build M=/home/sagar/module1 modules
make[1]: Entering directory `/usr/src/linux-headers-3.5.0-17-generic'
scripts/Makefile.build:44: /home/sagar/module1/Makefile: No such file or directory
make[2]: *** No rule to make target `/home/sagar/module1/Makefile'.  Stop.
make[1]: *** [_module_/home/sagar/module1] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-3.5.0-17-generic'
make: *** [build] Error 2