fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / kernel / user.c

diff --git a/kernel/user.c b/kernel/user.c
index 155084e..902de43 100644 (file)
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -26,7 +26,7 @@
 #define __uidhashfn(xid,uid)   ((((uid) >> UIDHASH_BITS) + ((uid)^(xid))) & UIDHASH_MASK)
 #define uidhashentry(xid,uid)  (uidhash_table + __uidhashfn((xid),(uid)))
 
-static kmem_cache_t *uid_cachep;
+static struct kmem_cache *uid_cachep;
 static struct list_head uidhash_table[UIDHASH_SZ];
 
 /*
@@ -105,15 +105,19 @@ void free_uid(struct user_struct *up)
 {
        unsigned long flags;
 
+       if (!up)
+               return;
+
        local_irq_save(flags);
-       if (up && atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
+       if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) {
                uid_hash_remove(up);
+               spin_unlock_irqrestore(&uidhash_lock, flags);
                key_put(up->uid_keyring);
                key_put(up->session_keyring);
                kmem_cache_free(uid_cachep, up);
-               spin_unlock(&uidhash_lock);
+       } else {
+               local_irq_restore(flags);
        }
-       local_irq_restore(flags);
 }
 
 struct user_struct * alloc_uid(xid_t xid, uid_t uid)
@@ -128,7 +132,7 @@ struct user_struct * alloc_uid(xid_t xid, uid_t uid)
        if (!up) {
                struct user_struct *new;
 
-               new = kmem_cache_alloc(uid_cachep, SLAB_KERNEL);
+               new = kmem_cache_alloc(uid_cachep, GFP_KERNEL);
                if (!new)
                        return NULL;
                new->uid = uid;
@@ -137,7 +141,7 @@ struct user_struct * alloc_uid(xid_t xid, uid_t uid)
                atomic_set(&new->processes, 0);
                atomic_set(&new->files, 0);
                atomic_set(&new->sigpending, 0);
-#ifdef CONFIG_INOTIFY
+#ifdef CONFIG_INOTIFY_USER
                atomic_set(&new->inotify_watches, 0);
                atomic_set(&new->inotify_devs, 0);
 #endif
@@ -145,7 +149,7 @@ struct user_struct * alloc_uid(xid_t xid, uid_t uid)
                new->mq_bytes = 0;
                new->locked_shm = 0;
 
-               if (alloc_uid_keyring(new) < 0) {
+               if (alloc_uid_keyring(new, current) < 0) {
                        kmem_cache_free(uid_cachep, new);
                        return NULL;
                }
@@ -184,6 +188,17 @@ void switch_uid(struct user_struct *new_user)
        atomic_dec(&old_user->processes);
        switch_uid_keyring(new_user);
        current->user = new_user;
+
+       /*
+        * 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(&current->sighand->siglock);
+
        free_uid(old_user);
        suid_keys(current);
 }