| /* |
| * 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/export.h> |
| #include <linux/init.h> |
| #include <linux/kexec.h> |
| #include <linux/profile.h> |
| #include <linux/stat.h> |
| #include <linux/sched.h> |
| #include <linux/capability.h> |
| #include <linux/compiler.h> |
| |
| #include <linux/rcupdate.h> /* rcu_expedited and rcu_normal */ |
| |
| #define KERNEL_ATTR_RO(_name) \ |
| static struct kobj_attribute _name##_attr = __ATTR_RO(_name) |
| |
| #define KERNEL_ATTR_RW(_name) \ |
| static struct kobj_attribute _name##_attr = \ |
| __ATTR(_name, 0644, _name##_show, _name##_store) |
| |
| /* current uevent sequence number */ |
| static ssize_t uevent_seqnum_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum); |
| } |
| KERNEL_ATTR_RO(uevent_seqnum); |
| |
| #ifdef CONFIG_UEVENT_HELPER |
| /* uevent helper program, used during early boot */ |
| static ssize_t uevent_helper_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%s\n", uevent_helper); |
| } |
| static ssize_t uevent_helper_store(struct kobject *kobj, |
| struct kobj_attribute *attr, |
| const char *buf, size_t count) |
| { |
| if (count+1 > UEVENT_HELPER_PATH_LEN) |
| return -ENOENT; |
| memcpy(uevent_helper, buf, 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_PROFILING |
| static ssize_t profiling_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", prof_on); |
| } |
| static ssize_t profiling_store(struct kobject *kobj, |
| struct kobj_attribute *attr, |
| const char *buf, size_t count) |
| { |
| int ret; |
| |
| if (prof_on) |
| return -EEXIST; |
| /* |
| * This eventually calls into get_option() which |
| * has a ton of callers and is not const. It is |
| * easiest to cast it away here. |
| */ |
| profile_setup((char *)buf); |
| ret = profile_init(); |
| if (ret) |
| return ret; |
| ret = create_proc_profile(); |
| if (ret) |
| return ret; |
| return count; |
| } |
| KERNEL_ATTR_RW(profiling); |
| #endif |
| |
| #ifdef CONFIG_KEXEC_CORE |
| static ssize_t kexec_loaded_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", !!kexec_image); |
| } |
| KERNEL_ATTR_RO(kexec_loaded); |
| |
| static ssize_t kexec_crash_loaded_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", !!kexec_crash_image); |
| } |
| KERNEL_ATTR_RO(kexec_crash_loaded); |
| |
| static ssize_t kexec_crash_size_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%zu\n", crash_get_memory_size()); |
| } |
| static ssize_t kexec_crash_size_store(struct kobject *kobj, |
| struct kobj_attribute *attr, |
| const char *buf, size_t count) |
| { |
| unsigned long cnt; |
| int ret; |
| |
| if (kstrtoul(buf, 0, &cnt)) |
| return -EINVAL; |
| |
| ret = crash_shrink_memory(cnt); |
| return ret < 0 ? ret : count; |
| } |
| KERNEL_ATTR_RW(kexec_crash_size); |
| |
| static ssize_t vmcoreinfo_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%lx %x\n", |
| paddr_vmcoreinfo_note(), |
| (unsigned int)sizeof(vmcoreinfo_note)); |
| } |
| KERNEL_ATTR_RO(vmcoreinfo); |
| |
| #endif /* CONFIG_KEXEC_CORE */ |
| |
| /* whether file capabilities are enabled */ |
| static ssize_t fscaps_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", file_caps_enabled); |
| } |
| KERNEL_ATTR_RO(fscaps); |
| |
| #ifndef CONFIG_TINY_RCU |
| int rcu_expedited; |
| static ssize_t rcu_expedited_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", READ_ONCE(rcu_expedited)); |
| } |
| static ssize_t rcu_expedited_store(struct kobject *kobj, |
| struct kobj_attribute *attr, |
| const char *buf, size_t count) |
| { |
| if (kstrtoint(buf, 0, &rcu_expedited)) |
| return -EINVAL; |
| |
| return count; |
| } |
| KERNEL_ATTR_RW(rcu_expedited); |
| |
| int rcu_normal; |
| static ssize_t rcu_normal_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", READ_ONCE(rcu_normal)); |
| } |
| static ssize_t rcu_normal_store(struct kobject *kobj, |
| struct kobj_attribute *attr, |
| const char *buf, size_t count) |
| { |
| if (kstrtoint(buf, 0, &rcu_normal)) |
| return -EINVAL; |
| |
| return count; |
| } |
| KERNEL_ATTR_RW(rcu_normal); |
| #endif /* #ifndef CONFIG_TINY_RCU */ |
| |
| /* |
| * Make /sys/kernel/notes give the raw contents of our kernel .notes section. |
| */ |
| extern const void __start_notes __weak; |
| extern const void __stop_notes __weak; |
| #define notes_size (&__stop_notes - &__start_notes) |
| |
| static ssize_t notes_read(struct file *filp, 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, |
| }; |
| |
| struct kobject *kernel_kobj; |
| EXPORT_SYMBOL_GPL(kernel_kobj); |
| |
| static struct attribute * kernel_attrs[] = { |
| &fscaps_attr.attr, |
| &uevent_seqnum_attr.attr, |
| #ifdef CONFIG_UEVENT_HELPER |
| &uevent_helper_attr.attr, |
| #endif |
| #ifdef CONFIG_PROFILING |
| &profiling_attr.attr, |
| #endif |
| #ifdef CONFIG_KEXEC_CORE |
| &kexec_loaded_attr.attr, |
| &kexec_crash_loaded_attr.attr, |
| &kexec_crash_size_attr.attr, |
| &vmcoreinfo_attr.attr, |
| #endif |
| #ifndef CONFIG_TINY_RCU |
| &rcu_expedited_attr.attr, |
| &rcu_normal_attr.attr, |
| #endif |
| NULL |
| }; |
| |
| static struct attribute_group kernel_attr_group = { |
| .attrs = kernel_attrs, |
| }; |
| |
| static int __init ksysfs_init(void) |
| { |
| int error; |
| |
| kernel_kobj = kobject_create_and_add("kernel", NULL); |
| if (!kernel_kobj) { |
| error = -ENOMEM; |
| goto exit; |
| } |
| error = sysfs_create_group(kernel_kobj, &kernel_attr_group); |
| if (error) |
| goto kset_exit; |
| |
| if (notes_size > 0) { |
| notes_attr.size = notes_size; |
| error = sysfs_create_bin_file(kernel_kobj, ¬es_attr); |
| if (error) |
| goto group_exit; |
| } |
| |
| return 0; |
| |
| group_exit: |
| sysfs_remove_group(kernel_kobj, &kernel_attr_group); |
| kset_exit: |
| kobject_put(kernel_kobj); |
| exit: |
| return error; |
| } |
| |
| core_initcall(ksysfs_init); |