/* * 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 kset *kset, 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 kset *kset, char *page) { return sprintf(page, "%s\n", uevent_helper); } static ssize_t uevent_helper_store(struct kset *kset, 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 kset *kset, char *page) { return sprintf(page, "%d\n", !!kexec_image); } KERNEL_ATTR_RO(kexec_loaded); static ssize_t kexec_crash_loaded_show(struct kset *kset, char *page) { return sprintf(page, "%d\n", !!kexec_crash_image); } KERNEL_ATTR_RO(kexec_crash_loaded); #endif /* CONFIG_KEXEC */ /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ extern const void __start_notes __attribute__((weak)); extern const void __stop_notes __attribute__((weak)); #define notes_size (&__stop_notes - &__start_notes) static ssize_t notes_read(struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { memcpy(buf, &__start_notes + off, count); return count; } static struct bin_attribute notes_attr = { .attr = { .name = "notes", .mode = S_IRUGO, }, .read = ¬es_read, }; 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.kobj, &kernel_attr_group); if (!error && notes_size > 0) { notes_attr.size = notes_size; error = sysfs_create_bin_file(&kernel_subsys.kobj, ¬es_attr); } return error; } core_initcall(ksysfs_init);