+#ifdef CONFIG_USER_SCHED
+
+static void sched_destroy_user(struct user_struct *up)
+{
+ sched_destroy_group(up->tg);
+}
+
+static int sched_create_user(struct user_struct *up)
+{
+ int rc = 0;
+
+ up->tg = sched_create_group();
+ if (IS_ERR(up->tg))
+ rc = -ENOMEM;
+
+ return rc;
+}
+
+static void sched_switch_user(struct task_struct *p)
+{
+ sched_move_task(p);
+}
+
+#else /* CONFIG_USER_SCHED */
+
+static void sched_destroy_user(struct user_struct *up) { }
+static int sched_create_user(struct user_struct *up) { return 0; }
+static void sched_switch_user(struct task_struct *p) { }
+
+#endif /* CONFIG_USER_SCHED */
+
+#if defined(CONFIG_USER_SCHED) && defined(CONFIG_SYSFS)
+
+static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */
+static DEFINE_MUTEX(uids_mutex);
+
+static inline void uids_mutex_lock(void)
+{
+ mutex_lock(&uids_mutex);
+}
+
+static inline void uids_mutex_unlock(void)
+{
+ mutex_unlock(&uids_mutex);
+}
+
+/* uid directory attributes */
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static ssize_t cpu_shares_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ struct user_struct *up = container_of(kobj, struct user_struct, kobj);
+
+ return sprintf(buf, "%lu\n", sched_group_shares(up->tg));
+}
+
+static ssize_t cpu_shares_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct user_struct *up = container_of(kobj, struct user_struct, kobj);
+ unsigned long shares;
+ int rc;
+
+ sscanf(buf, "%lu", &shares);
+
+ rc = sched_group_set_shares(up->tg, shares);
+
+ return (rc ? rc : size);
+}
+
+static struct kobj_attribute cpu_share_attr =
+ __ATTR(cpu_share, 0644, cpu_shares_show, cpu_shares_store);
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static ssize_t cpu_rt_runtime_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ struct user_struct *up = container_of(kobj, struct user_struct, kobj);
+
+ return sprintf(buf, "%lu\n", sched_group_rt_runtime(up->tg));
+}
+
+static ssize_t cpu_rt_runtime_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct user_struct *up = container_of(kobj, struct user_struct, kobj);
+ unsigned long rt_runtime;
+ int rc;
+
+ sscanf(buf, "%lu", &rt_runtime);
+
+ rc = sched_group_set_rt_runtime(up->tg, rt_runtime);
+
+ return (rc ? rc : size);
+}
+
+static struct kobj_attribute cpu_rt_runtime_attr =
+ __ATTR(cpu_rt_runtime, 0644, cpu_rt_runtime_show, cpu_rt_runtime_store);
+#endif
+
+/* default attributes per uid directory */
+static struct attribute *uids_attributes[] = {
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ &cpu_share_attr.attr,
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+ &cpu_rt_runtime_attr.attr,
+#endif
+ NULL
+};
+
+/* the lifetime of user_struct is not managed by the core (now) */
+static void uids_release(struct kobject *kobj)
+{
+ return;
+}
+
+static struct kobj_type uids_ktype = {
+ .sysfs_ops = &kobj_sysfs_ops,
+ .default_attrs = uids_attributes,
+ .release = uids_release,
+};
+
+/* create /sys/kernel/uids/<uid>/cpu_share file for this user */
+static int uids_user_create(struct user_struct *up)
+{
+ struct kobject *kobj = &up->kobj;
+ int error;
+
+ memset(kobj, 0, sizeof(struct kobject));
+ kobj->kset = uids_kset;
+ error = kobject_init_and_add(kobj, &uids_ktype, NULL, "%d", up->uid);
+ if (error) {
+ kobject_put(kobj);
+ goto done;
+ }
+
+ kobject_uevent(kobj, KOBJ_ADD);
+done:
+ return error;
+}
+
+/* create these entries in sysfs:
+ * "/sys/kernel/uids" directory
+ * "/sys/kernel/uids/0" directory (for root user)
+ * "/sys/kernel/uids/0/cpu_share" file (for root user)
+ */
+int __init uids_sysfs_init(void)
+{
+ uids_kset = kset_create_and_add("uids", NULL, kernel_kobj);
+ if (!uids_kset)
+ return -ENOMEM;
+
+ return uids_user_create(&root_user);
+}
+
+/* work function to remove sysfs directory for a user and free up
+ * corresponding structures.
+ */
+static void remove_user_sysfs_dir(struct work_struct *w)
+{
+ struct user_struct *up = container_of(w, struct user_struct, work);
+ unsigned long flags;
+ int remove_user = 0;
+
+ /* Make uid_hash_remove() + sysfs_remove_file() + kobject_del()
+ * atomic.
+ */
+ uids_mutex_lock();
+
+ local_irq_save(flags);
+
+ if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
+ uid_hash_remove(up);
+ remove_user = 1;
+ spin_unlock_irqrestore(&uidhash_lock, flags);
+ } else {
+ local_irq_restore(flags);
+ }
+
+ if (!remove_user)
+ goto done;
+
+ kobject_uevent(&up->kobj, KOBJ_REMOVE);
+ kobject_del(&up->kobj);
+ kobject_put(&up->kobj);
+
+ sched_destroy_user(up);
+ key_put(up->uid_keyring);
+ key_put(up->session_keyring);
+ kmem_cache_free(uid_cachep, up);
+
+done:
+ uids_mutex_unlock();
+}
+
+/* IRQs are disabled and uidhash_lock is held upon function entry.
+ * IRQ state (as stored in flags) is restored and uidhash_lock released
+ * upon function exit.
+ */
+static inline void free_user(struct user_struct *up, unsigned long flags)
+{
+ /* restore back the count */
+ atomic_inc(&up->__count);
+ spin_unlock_irqrestore(&uidhash_lock, flags);
+
+ INIT_WORK(&up->work, remove_user_sysfs_dir);
+ schedule_work(&up->work);
+}
+
+#else /* CONFIG_USER_SCHED && CONFIG_SYSFS */
+
+int uids_sysfs_init(void) { return 0; }
+static inline int uids_user_create(struct user_struct *up) { return 0; }
+static inline void uids_mutex_lock(void) { }
+static inline void uids_mutex_unlock(void) { }
+
+/* IRQs are disabled and uidhash_lock is held upon function entry.
+ * IRQ state (as stored in flags) is restored and uidhash_lock released
+ * upon function exit.
+ */
+static inline void free_user(struct user_struct *up, unsigned long flags)
+{
+ uid_hash_remove(up);
+ spin_unlock_irqrestore(&uidhash_lock, flags);
+ sched_destroy_user(up);
+ key_put(up->uid_keyring);
+ key_put(up->session_keyring);
+ kmem_cache_free(uid_cachep, up);
+}
+
+#endif
+