| /* |
| * 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); |