[mirror_ubuntu-bionic-kernel.git] / kernel / ksysfs.c

/*
 * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
 * 		     are not related to any other subsystem
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 * 
 * This file is release under the GPLv2
 *
 */

#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kexec.h>

#define KERNEL_ATTR_RO(_name) \
static struct subsys_attribute _name##_attr = __ATTR_RO(_name)

#define KERNEL_ATTR_RW(_name) \
static struct subsys_attribute _name##_attr = \
	__ATTR(_name, 0644, _name##_show, _name##_store)

#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
/* current uevent sequence number */
static ssize_t uevent_seqnum_show(struct subsystem *subsys, char *page)
{
	return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
}
KERNEL_ATTR_RO(uevent_seqnum);

/* uevent helper program, used during early boo */
static ssize_t uevent_helper_show(struct subsystem *subsys, char *page)
{
	return sprintf(page, "%s\n", uevent_helper);
}
static ssize_t uevent_helper_store(struct subsystem *subsys, const char *page, size_t count)
{
	if (count+1 > UEVENT_HELPER_PATH_LEN)
		return -ENOENT;
	memcpy(uevent_helper, page, count);
	uevent_helper[count] = '\0';
	if (count && uevent_helper[count-1] == '\n')
		uevent_helper[count-1] = '\0';
	return count;
}
KERNEL_ATTR_RW(uevent_helper);
#endif

#ifdef CONFIG_KEXEC
static ssize_t kexec_loaded_show(struct subsystem *subsys, char *page)
{
	return sprintf(page, "%d\n", !!kexec_image);
}
KERNEL_ATTR_RO(kexec_loaded);

static ssize_t kexec_crash_loaded_show(struct subsystem *subsys, char *page)
{
	return sprintf(page, "%d\n", !!kexec_crash_image);
}
KERNEL_ATTR_RO(kexec_crash_loaded);
#endif /* CONFIG_KEXEC */

decl_subsys(kernel, NULL, NULL);
EXPORT_SYMBOL_GPL(kernel_subsys);

static struct attribute * kernel_attrs[] = {
#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
	&uevent_seqnum_attr.attr,
	&uevent_helper_attr.attr,
#endif
#ifdef CONFIG_KEXEC
	&kexec_loaded_attr.attr,
	&kexec_crash_loaded_attr.attr,
#endif
	NULL
};

static struct attribute_group kernel_attr_group = {
	.attrs = kernel_attrs,
};

static int __init ksysfs_init(void)
{
	int error = subsystem_register(&kernel_subsys);
	if (!error)
		error = sysfs_create_group(&kernel_subsys.kset.kobj,
					   &kernel_attr_group);

	return error;
}

core_initcall(ksysfs_init);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
	3	* are not related to any other subsystem
	4	*
	5	* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
	6	*
	7	* This file is release under the GPLv2
	8	*
	9	*/
	10
1da177e4 LT	11	#include <linux/kobject.h>
	12	#include <linux/string.h>
	13	#include <linux/sysfs.h>
	14	#include <linux/module.h>
	15	#include <linux/init.h>
c330dda9	16	#include <linux/kexec.h>
1da177e4 LT	17
	18	#define KERNEL_ATTR_RO(_name) \
	19	static struct subsys_attribute _name##_attr = __ATTR_RO(_name)
	20
	21	#define KERNEL_ATTR_RW(_name) \
	22	static struct subsys_attribute _name##_attr = \
	23	__ATTR(_name, 0644, _name##_show, _name##_store)
	24
f125b561	25	#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
0f76e5ac KS	26	/* current uevent sequence number */
0f76e5ac KS	27	static ssize_t uevent_seqnum_show(struct subsystem subsys, char page)
1da177e4	28	{
312c004d	29	return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
1da177e4	30	}
0f76e5ac KS	31	KERNEL_ATTR_RO(uevent_seqnum);
	32
	33	/* uevent helper program, used during early boo */
	34	static ssize_t uevent_helper_show(struct subsystem subsys, char page)
	35	{
312c004d	36	return sprintf(page, "%s\n", uevent_helper);
0f76e5ac KS	37	}
	38	static ssize_t uevent_helper_store(struct subsystem subsys, const char page, size_t count)
	39	{
312c004d	40	if (count+1 > UEVENT_HELPER_PATH_LEN)
0f76e5ac	41	return -ENOENT;
312c004d KS	42	memcpy(uevent_helper, page, count);
	43	uevent_helper[count] = '\0';
	44	if (count && uevent_helper[count-1] == '\n')
	45	uevent_helper[count-1] = '\0';
0f76e5ac KS	46	return count;
	47	}
	48	KERNEL_ATTR_RW(uevent_helper);
1da177e4 LT	49	#endif
1da177e4 LT	50
c330dda9 JM	51	#ifdef CONFIG_KEXEC
	52	static ssize_t kexec_loaded_show(struct subsystem subsys, char page)
	53	{
	54	return sprintf(page, "%d\n", !!kexec_image);
	55	}
	56	KERNEL_ATTR_RO(kexec_loaded);
	57
	58	static ssize_t kexec_crash_loaded_show(struct subsystem subsys, char page)
	59	{
	60	return sprintf(page, "%d\n", !!kexec_crash_image);
	61	}
	62	KERNEL_ATTR_RO(kexec_crash_loaded);
	63	#endif /* CONFIG_KEXEC */
	64
1da177e4 LT	65	decl_subsys(kernel, NULL, NULL);
	66	EXPORT_SYMBOL_GPL(kernel_subsys);
	67
	68	static struct attribute * kernel_attrs[] = {
f125b561	69	#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
0f76e5ac KS	70	&uevent_seqnum_attr.attr,
0f76e5ac KS	71	&uevent_helper_attr.attr,
c330dda9 JM	72	#endif
	73	#ifdef CONFIG_KEXEC
	74	&kexec_loaded_attr.attr,
	75	&kexec_crash_loaded_attr.attr,
1da177e4 LT	76	#endif
	77	NULL
	78	};
	79
	80	static struct attribute_group kernel_attr_group = {
	81	.attrs = kernel_attrs,
	82	};
	83
	84	static int __init ksysfs_init(void)
	85	{
	86	int error = subsystem_register(&kernel_subsys);
	87	if (!error)
	88	error = sysfs_create_group(&kernel_subsys.kset.kobj,
	89	&kernel_attr_group);
	90
	91	return error;
	92	}
	93
	94	core_initcall(ksysfs_init);