diff options
Diffstat (limited to 'kernel/ksysfs.c')
| -rw-r--r-- | kernel/ksysfs.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c new file mode 100644 index 0000000..08dd8ed --- /dev/null +++ b/kernel/ksysfs.c @@ -0,0 +1,197 @@ +/* + * 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> +#include <linux/profile.h> +#include <linux/sched.h> + +#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) + +#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) +/* 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); + +/* uevent helper program, used during early boo */ +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 +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 vmcoreinfo_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%lx %x\n", + paddr_vmcoreinfo_note(), + (unsigned int)vmcoreinfo_max_size); +} +KERNEL_ATTR_RO(vmcoreinfo); + +#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, +}; + +struct kobject *kernel_kobj; +EXPORT_SYMBOL_GPL(kernel_kobj); + +static struct attribute * kernel_attrs[] = { +#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET) + &uevent_seqnum_attr.attr, + &uevent_helper_attr.attr, +#endif +#ifdef CONFIG_PROFILING + &profiling_attr.attr, +#endif +#ifdef CONFIG_KEXEC + &kexec_loaded_attr.attr, + &kexec_crash_loaded_attr.attr, + &vmcoreinfo_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; + } + + /* create the /sys/kernel/uids/ directory */ + error = uids_sysfs_init(); + if (error) + goto notes_exit; + + return 0; + +notes_exit: + if (notes_size > 0) + sysfs_remove_bin_file(kernel_kobj, ¬es_attr); +group_exit: + sysfs_remove_group(kernel_kobj, &kernel_attr_group); +kset_exit: + kobject_put(kernel_kobj); +exit: + return error; +} + +core_initcall(ksysfs_init); |
