Module verification failed when insmod a module - linux

Question

On Ubuntu 14.04, Kernel 3.13.0, When I insert below simple module, I got error message from kernel log:
"module verification failed: signature and/or required key missing - tainting kernel"
Did I made any mistake or missed anything?
Here is module source code in a file named ts2.c.
#include <linux/module.h> /* Needed by all modules */
#include <linux/kernel.h> /* Needed for KERN_INFO */
#include <linux/init.h>
MODULE_LICENSE("GPL");
MODULE_ALIAS("hello2");
static int __init hello1_init(void)
{
printk(KERN_INFO "Hello world 2.\n");
return 0;
}
static void __exit hello1_exit(void)
{
printk(KERN_INFO "Goodbye world 2.\n");
}
module_init(hello1_init);
module_exit(hello1_exit);
Here is the Makefile:
ifeq ($(DEBUG),y)
DEBFLAGS = -O -g -DPCI_INFO_DEBUG # "-O" is needed to expand inlines
else
DEBFLAGS = -O2
endif
EXTRA_CFLAGS += $(DEBFLAGS) -I$(LDDINC)
ifneq ($(KERNELRELEASE),)
obj-m := ts2.o
else
KERNELDIR ?= /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
modules:
$(MAKE) -C $(KERNELDIR) M=$(PWD) LDDINC=$(PWD) modules
clean:
$(MAKE) -C $(KERNELDIR) M=$(PWD) LDDINC=$(PWD) clean
endif
depend .depend dep:
$(CC) $(EXTRA_CFLAGS) -M *.c > .depend
ifeq (.depend,$(wildcard .depend))
include .depend
endif

Answer 1

You have a problem in your make file...
ifeq ($(DEBUG),y)
DEBFLAGS = -O -g -DPCI_INFO_DEBUG # "-O" is needed to expand inlines
else
DEBFLAGS = -O2
endif
EXTRA_CFLAGS += $(DEBFLAGS) -I$(LDDINC)
ifneq ($(KERNELRELEASE),)
obj-m := ts2.o
Rather it should be as below:
ifeq ($(DEBUG),y)
DEBFLAGS = -O -g -DPCI_INFO_DEBUG # "-O" is needed to expand inlines
else
DEBFLAGS = -O2
endif
EXTRA_CFLAGS += $(DEBFLAGS) -I$(LDDINC)
ifneq ($(KERNELRELEASE),)
obj-m := hello1.o
Now your issues should be solved