/* * 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_KEXECstatic 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);