.kref = {
.refcount = ATOMIC_INIT(2),
},
- .root_user = &root_user,
+ .creator = &root_user,
};
EXPORT_SYMBOL_GPL(init_user_ns);
*/
static DEFINE_SPINLOCK(uidhash_lock);
+/* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->creator */
struct user_struct root_user = {
- .__count = ATOMIC_INIT(1),
+ .__count = ATOMIC_INIT(2),
.processes = ATOMIC_INIT(1),
.files = ATOMIC_INIT(0),
.sigpending = ATOMIC_INIT(0),
.locked_shm = 0,
-#ifdef CONFIG_KEYS
- .uid_keyring = &root_user_keyring,
- .session_keyring = &root_session_keyring,
-#endif
-#ifdef CONFIG_FAIR_USER_SCHED
- .tg = &init_task_group,
-#endif
+ .user_ns = &init_user_ns,
};
/*
static void uid_hash_remove(struct user_struct *up)
{
hlist_del_init(&up->uidhash_node);
+ put_user_ns(up->user_ns);
}
static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
return NULL;
}
-#ifdef CONFIG_FAIR_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_FAIR_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_FAIR_USER_SCHED */
-
-#if defined(CONFIG_FAIR_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 */
-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);
-
-/* default attributes per uid directory */
-static struct attribute *uids_attributes[] = {
- &cpu_share_attr.attr,
- 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_FAIR_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)
+static 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
-
/*
* Locate the user_struct for the passed UID. If found, take a ref on it. The
* caller must undo that ref with free_uid().
{
struct user_struct *ret;
unsigned long flags;
- struct user_namespace *ns = current->nsproxy->user_ns;
+ struct user_namespace *ns = current_user_ns();
spin_lock_irqsave(&uidhash_lock, flags);
ret = uid_hash_find(uid, uidhashentry(ns, uid));
local_irq_restore(flags);
}
-struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid)
+struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
{
struct hlist_head *hashent = uidhashentry(ns, uid);
struct user_struct *up, *new;
- /* Make uid_hash_find() + uids_user_create() + uid_hash_insert()
- * atomic.
- */
- uids_mutex_lock();
-
+ /* Make uid_hash_find() + uid_hash_insert() atomic. */
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
spin_unlock_irq(&uidhash_lock);
if (!up) {
- new = kmem_cache_alloc(uid_cachep, GFP_KERNEL);
+ new = kmem_cache_zalloc(uid_cachep, GFP_KERNEL);
if (!new)
goto out_unlock;
new->uid = uid;
atomic_set(&new->__count, 1);
- atomic_set(&new->processes, 0);
- atomic_set(&new->files, 0);
- atomic_set(&new->sigpending, 0);
-#ifdef CONFIG_INOTIFY_USER
- atomic_set(&new->inotify_watches, 0);
- atomic_set(&new->inotify_devs, 0);
-#endif
-#ifdef CONFIG_POSIX_MQUEUE
- new->mq_bytes = 0;
-#endif
- new->locked_shm = 0;
-
- if (alloc_uid_keyring(new, current) < 0)
- goto out_free_user;
-
- if (sched_create_user(new) < 0)
- goto out_put_keys;
-
- if (uids_user_create(new))
- goto out_destoy_sched;
+
+ new->user_ns = get_user_ns(ns);
/*
* Before adding this, check whether we raced
spin_lock_irq(&uidhash_lock);
up = uid_hash_find(uid, hashent);
if (up) {
- /* This case is not possible when CONFIG_FAIR_USER_SCHED
- * is defined, since we serialize alloc_uid() using
- * uids_mutex. Hence no need to call
- * sched_destroy_user() or remove_user_sysfs_dir().
- */
key_put(new->uid_keyring);
key_put(new->session_keyring);
kmem_cache_free(uid_cachep, new);
up = new;
}
spin_unlock_irq(&uidhash_lock);
-
}
- uids_mutex_unlock();
-
return up;
-out_destoy_sched:
- sched_destroy_user(new);
-out_put_keys:
- key_put(new->uid_keyring);
- key_put(new->session_keyring);
-out_free_user:
- kmem_cache_free(uid_cachep, new);
out_unlock:
- uids_mutex_unlock();
return NULL;
}
-void switch_uid(struct user_struct *new_user)
-{
- struct user_struct *old_user;
-
- /* What if a process setreuid()'s and this brings the
- * new uid over his NPROC rlimit? We can check this now
- * cheaply with the new uid cache, so if it matters
- * we should be checking for it. -DaveM
- */
- old_user = current->user;
- atomic_inc(&new_user->processes);
- atomic_dec(&old_user->processes);
- switch_uid_keyring(new_user);
- current->user = new_user;
- sched_switch_user(current);
-
- /*
- * We need to synchronize with __sigqueue_alloc()
- * doing a get_uid(p->user).. If that saw the old
- * user value, we need to wait until it has exited
- * its critical region before we can free the old
- * structure.
- */
- smp_mb();
- spin_unlock_wait(¤t->sighand->siglock);
-
- free_uid(old_user);
- suid_keys(current);
-}
-
-#ifdef CONFIG_USER_NS
-void release_uids(struct user_namespace *ns)
-{
- int i;
- unsigned long flags;
- struct hlist_head *head;
- struct hlist_node *nd;
-
- spin_lock_irqsave(&uidhash_lock, flags);
- /*
- * collapse the chains so that the user_struct-s will
- * be still alive, but not in hashes. subsequent free_uid()
- * will free them.
- */
- for (i = 0; i < UIDHASH_SZ; i++) {
- head = ns->uidhash_table + i;
- while (!hlist_empty(head)) {
- nd = head->first;
- hlist_del_init(nd);
- }
- }
- spin_unlock_irqrestore(&uidhash_lock, flags);
-
- free_uid(ns->root_user);
-}
-#endif
-
static int __init uid_cache_init(void)
{
int n;
Code Review / linux-2.6.git / blobdiff