mmc: s3c6410: enable ADMA feature in 6410 sdhci controller
[safe/jmp/linux-2.6] / kernel / futex.c
index 320b369..e7a35f1 100644 (file)
@@ -203,8 +203,6 @@ static void drop_futex_key_refs(union futex_key *key)
  * @uaddr:     virtual address of the futex
  * @fshared:   0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
  * @key:       address where result is stored.
- * @rw:                mapping needs to be read/write (values: VERIFY_READ,
- *             VERIFY_WRITE)
  *
  * Returns a negative error code or 0
  * The key words are stored in *key on success.
@@ -216,7 +214,7 @@ static void drop_futex_key_refs(union futex_key *key)
  * lock_page() might sleep, the caller should not hold a spinlock.
  */
 static int
-get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
+get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key)
 {
        unsigned long address = (unsigned long)uaddr;
        struct mm_struct *mm = current->mm;
@@ -239,7 +237,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
         *        but access_ok() should be faster than find_vma()
         */
        if (!fshared) {
-               if (unlikely(!access_ok(rw, uaddr, sizeof(u32))))
+               if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
                        return -EFAULT;
                key->private.mm = mm;
                key->private.address = address;
@@ -248,7 +246,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
        }
 
 again:
-       err = get_user_pages_fast(address, 1, rw == VERIFY_WRITE, &page);
+       err = get_user_pages_fast(address, 1, 1, &page);
        if (err < 0)
                return err;
 
@@ -532,8 +530,25 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
                                return -EINVAL;
 
                        WARN_ON(!atomic_read(&pi_state->refcount));
-                       WARN_ON(pid && pi_state->owner &&
-                               pi_state->owner->pid != pid);
+
+                       /*
+                        * When pi_state->owner is NULL then the owner died
+                        * and another waiter is on the fly. pi_state->owner
+                        * is fixed up by the task which acquires
+                        * pi_state->rt_mutex.
+                        *
+                        * We do not check for pid == 0 which can happen when
+                        * the owner died and robust_list_exit() cleared the
+                        * TID.
+                        */
+                       if (pid && pi_state->owner) {
+                               /*
+                                * Bail out if user space manipulated the
+                                * futex value.
+                                */
+                               if (pid != task_pid_vnr(pi_state->owner))
+                                       return -EINVAL;
+                       }
 
                        atomic_inc(&pi_state->refcount);
                        *ps = pi_state;
@@ -760,7 +775,14 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
        if (!pi_state)
                return -EINVAL;
 
-       spin_lock(&pi_state->pi_mutex.wait_lock);
+       /*
+        * If current does not own the pi_state then the futex is
+        * inconsistent and user space fiddled with the futex value.
+        */
+       if (pi_state->owner != current)
+               return -EINVAL;
+
+       raw_spin_lock(&pi_state->pi_mutex.wait_lock);
        new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
 
        /*
@@ -789,7 +811,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
                else if (curval != uval)
                        ret = -EINVAL;
                if (ret) {
-                       spin_unlock(&pi_state->pi_mutex.wait_lock);
+                       raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
                        return ret;
                }
        }
@@ -805,7 +827,7 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this)
        pi_state->owner = new_owner;
        raw_spin_unlock_irq(&new_owner->pi_lock);
 
-       spin_unlock(&pi_state->pi_mutex.wait_lock);
+       raw_spin_unlock(&pi_state->pi_mutex.wait_lock);
        rt_mutex_unlock(&pi_state->pi_mutex);
 
        return 0;
@@ -867,7 +889,7 @@ static int futex_wake(u32 __user *uaddr, int fshared, int nr_wake, u32 bitset)
        if (!bitset)
                return -EINVAL;
 
-       ret = get_futex_key(uaddr, fshared, &key, VERIFY_READ);
+       ret = get_futex_key(uaddr, fshared, &key);
        if (unlikely(ret != 0))
                goto out;
 
@@ -913,10 +935,10 @@ futex_wake_op(u32 __user *uaddr1, int fshared, u32 __user *uaddr2,
        int ret, op_ret;
 
 retry:
-       ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
+       ret = get_futex_key(uaddr1, fshared, &key1);
        if (unlikely(ret != 0))
                goto out;
-       ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
+       ret = get_futex_key(uaddr2, fshared, &key2);
        if (unlikely(ret != 0))
                goto out_put_key1;
 
@@ -1175,11 +1197,10 @@ retry:
                pi_state = NULL;
        }
 
-       ret = get_futex_key(uaddr1, fshared, &key1, VERIFY_READ);
+       ret = get_futex_key(uaddr1, fshared, &key1);
        if (unlikely(ret != 0))
                goto out;
-       ret = get_futex_key(uaddr2, fshared, &key2,
-                           requeue_pi ? VERIFY_WRITE : VERIFY_READ);
+       ret = get_futex_key(uaddr2, fshared, &key2);
        if (unlikely(ret != 0))
                goto out_put_key1;
 
@@ -1738,7 +1759,7 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, int fshared,
         */
 retry:
        q->key = FUTEX_KEY_INIT;
-       ret = get_futex_key(uaddr, fshared, &q->key, VERIFY_READ);
+       ret = get_futex_key(uaddr, fshared, &q->key);
        if (unlikely(ret != 0))
                return ret;
 
@@ -1904,7 +1925,7 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
        q.requeue_pi_key = NULL;
 retry:
        q.key = FUTEX_KEY_INIT;
-       ret = get_futex_key(uaddr, fshared, &q.key, VERIFY_WRITE);
+       ret = get_futex_key(uaddr, fshared, &q.key);
        if (unlikely(ret != 0))
                goto out;
 
@@ -1974,7 +1995,7 @@ retry_private:
        /* Unqueue and drop the lock */
        unqueue_me_pi(&q);
 
-       goto out;
+       goto out_put_key;
 
 out_unlock_put_key:
        queue_unlock(&q, hb);
@@ -2023,7 +2044,7 @@ retry:
        if ((uval & FUTEX_TID_MASK) != task_pid_vnr(current))
                return -EPERM;
 
-       ret = get_futex_key(uaddr, fshared, &key, VERIFY_WRITE);
+       ret = get_futex_key(uaddr, fshared, &key);
        if (unlikely(ret != 0))
                goto out;
 
@@ -2215,7 +2236,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, int fshared,
        rt_waiter.task = NULL;
 
        key2 = FUTEX_KEY_INIT;
-       ret = get_futex_key(uaddr2, fshared, &key2, VERIFY_WRITE);
+       ret = get_futex_key(uaddr2, fshared, &key2);
        if (unlikely(ret != 0))
                goto out;