#define pr_fmt(fmt) "testmod: " fmt

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/kobject.h>

#include <linux/sysfs.h>

static struct kobject *testmod_kobj;

int value = 2;

static ssize_t value_show(struct kobject *kobj,

                          struct kobj_attribute *attr, char *buf)

{

	return sprintf(buf, "%d\n", value);

}

static struct kobj_attribute testmod_value_attr = __ATTR_RO(value);

static int testmod_init(void)

{

	int ret;

	testmod_kobj = kobject_create_and_add("testmod", kernel_kobj);

	if (!testmod_kobj)

		return -ENOMEM;

	ret = sysfs_create_file(testmod_kobj, &testmod_value_attr.attr);

	if (ret) {

		kobject_put(testmod_kobj);

		return ret;

	}

	return 0;

}

static void testmod_exit(void)

{

	sysfs_remove_file(testmod_kobj, &testmod_value_attr.attr);

	kobject_put(testmod_kobj);

}

module_init(testmod_init);

module_exit(testmod_exit);

MODULE_LICENSE("GPL");