#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/user_namespace.h>
+#include "cred-internals.h"
struct user_namespace init_user_ns = {
.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,
+ .user_ns = &init_user_ns,
#ifdef CONFIG_USER_SCHED
.tg = &init_task_group,
#endif
static void uid_hash_remove(struct user_struct *up)
{
hlist_del_init(&up->uidhash_node);
-}
-
-static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
-{
- struct user_struct *user;
- struct hlist_node *h;
-
- hlist_for_each_entry(user, h, hashent, uidhash_node) {
- if (user->uid == uid) {
- atomic_inc(&user->__count);
- return user;
- }
- }
-
- return NULL;
+ put_user_ns(up->user_ns);
}
#ifdef CONFIG_USER_SCHED
if (IS_ERR(up->tg))
rc = -ENOMEM;
- return rc;
-}
+ set_tg_uid(up);
-static void sched_switch_user(struct task_struct *p)
-{
- sched_move_task(p);
+ return rc;
}
#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 user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
+{
+ struct user_struct *user;
+ struct hlist_node *h;
+
+ hlist_for_each_entry(user, h, hashent, uidhash_node) {
+ if (user->uid == uid) {
+ /* possibly resurrect an "almost deleted" object */
+ if (atomic_inc_return(&user->__count) == 1)
+ cancel_delayed_work(&user->work);
+ return user;
+ }
+ }
+
+ return NULL;
+}
+
static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */
static DEFINE_MUTEX(uids_mutex);
.release = uids_release,
};
-/* create /sys/kernel/uids/<uid>/cpu_share file for this user */
+/*
+ * Create /sys/kernel/uids/<uid>/cpu_share file for this user
+ * We do not create this file for users in a user namespace (until
+ * sysfs tagging is implemented).
+ *
+ * See Documentation/scheduler/sched-design-CFS.txt for ramifications.
+ */
static int uids_user_create(struct user_struct *up)
{
struct kobject *kobj = &up->kobj;
int error;
memset(kobj, 0, sizeof(struct kobject));
+ if (up->user_ns != &init_user_ns)
+ return 0;
kobj->kset = uids_kset;
error = kobject_init_and_add(kobj, &uids_ktype, NULL, "%d", up->uid);
if (error) {
return uids_user_create(&root_user);
}
-/* work function to remove sysfs directory for a user and free up
+/* delayed work function to remove sysfs directory for a user and free up
* corresponding structures.
*/
-static void remove_user_sysfs_dir(struct work_struct *w)
+static void cleanup_user_struct(struct work_struct *w)
{
- struct user_struct *up = container_of(w, struct user_struct, work);
+ struct user_struct *up = container_of(w, struct user_struct, work.work);
unsigned long flags;
int remove_user = 0;
*/
uids_mutex_lock();
- local_irq_save(flags);
-
- if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
+ spin_lock_irqsave(&uidhash_lock, flags);
+ if (atomic_read(&up->__count) == 0) {
uid_hash_remove(up);
remove_user = 1;
- spin_unlock_irqrestore(&uidhash_lock, flags);
- } else {
- local_irq_restore(flags);
}
+ spin_unlock_irqrestore(&uidhash_lock, flags);
if (!remove_user)
goto done;
- kobject_uevent(&up->kobj, KOBJ_REMOVE);
- kobject_del(&up->kobj);
- kobject_put(&up->kobj);
+ if (up->user_ns == &init_user_ns) {
+ kobject_uevent(&up->kobj, KOBJ_REMOVE);
+ kobject_del(&up->kobj);
+ kobject_put(&up->kobj);
+ }
sched_destroy_user(up);
key_put(up->uid_keyring);
* 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)
{
- /* restore back the count */
- atomic_inc(&up->__count);
+ INIT_DELAYED_WORK(&up->work, cleanup_user_struct);
+ schedule_delayed_work(&up->work, msecs_to_jiffies(1000));
spin_unlock_irqrestore(&uidhash_lock, flags);
-
- INIT_WORK(&up->work, remove_user_sysfs_dir);
- schedule_work(&up->work);
}
#else /* CONFIG_USER_SCHED && CONFIG_SYSFS */
+static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
+{
+ struct user_struct *user;
+ struct hlist_node *h;
+
+ hlist_for_each_entry(user, h, hashent, uidhash_node) {
+ if (user->uid == uid) {
+ atomic_inc(&user->__count);
+ return user;
+ }
+ }
+
+ return NULL;
+}
+
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) { }
* 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);
#endif
+#if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
+/*
+ * We need to check if a setuid can take place. This function should be called
+ * before successfully completing the setuid.
+ */
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+
+ return sched_rt_can_attach(up->tg, tsk);
+
+}
+#else
+int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
+{
+ return 1;
+}
+#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));
if (sched_create_user(new) < 0)
goto out_free_user;
+ new->user_ns = get_user_ns(ns);
+
if (uids_user_create(new))
goto out_destoy_sched;
up = new;
}
spin_unlock_irq(&uidhash_lock);
-
}
uids_mutex_unlock();
out_destoy_sched:
sched_destroy_user(new);
+ put_user_ns(new->user_ns);
out_free_user:
kmem_cache_free(uid_cachep, new);
out_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;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff