Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus

[sfrench/cifs-2.6.git] / kernel / user.c

diff --git a/kernel/user.c b/kernel/user.c
index 6408c04242914191405dfef6a21b73948ef5ae73..4869563080e9e080954d26f34b70bbffc13de18b 100644 (file)
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -26,7 +26,7 @@
 #define __uidhashfn(uid)       (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK)
 #define uidhashentry(uid)      (uidhash_table + __uidhashfn((uid)))
 
-static kmem_cache_t *uid_cachep;
+static struct kmem_cache *uid_cachep;
 static struct list_head uidhash_table[UIDHASH_SZ];
 
 /*
@@ -132,7 +132,7 @@ struct user_struct * alloc_uid(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;
@@ -187,6 +187,17 @@ 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);
 }