futex: avoid wake_futex() for a PI futex_q

[pandora-kernel.git] / kernel / futex.c

diff --git a/kernel/futex.c b/kernel/futex.c
index 754427e..77bccfc 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -843,6 +843,9 @@ static void wake_futex(struct futex_q *q)
 {
        struct task_struct *p = q->task;
 
+       if (WARN(q->pi_state || q->rt_waiter, "refusing to wake PI futex\n"))
+               return;
+
        /*
         * We set q->lock_ptr = NULL _before_ we wake up the task. If
         * a non-futex wake up happens on another CPU then the task
@@ -1078,6 +1081,10 @@ retry_private:
 
        plist_for_each_entry_safe(this, next, head, list) {
                if (match_futex (&this->key, &key1)) {
+                       if (this->pi_state || this->rt_waiter) {
+                               ret = -EINVAL;
+                               goto out_unlock;
+                       }
                        wake_futex(this);
                        if (++ret >= nr_wake)
                                break;
@@ -1090,6 +1097,10 @@ retry_private:
                op_ret = 0;
                plist_for_each_entry_safe(this, next, head, list) {
                        if (match_futex (&this->key, &key2)) {
+                               if (this->pi_state || this->rt_waiter) {
+                                       ret = -EINVAL;
+                                       goto out_unlock;
+                               }
                                wake_futex(this);
                                if (++op_ret >= nr_wake2)
                                        break;
@@ -1098,6 +1109,7 @@ retry_private:
                ret += op_ret;
        }
 
+out_unlock:
        double_unlock_hb(hb1, hb2);
 out_put_keys:
        put_futex_key(&key2);
@@ -1387,9 +1399,13 @@ retry_private:
                /*
                 * FUTEX_WAIT_REQEUE_PI and FUTEX_CMP_REQUEUE_PI should always
                 * be paired with each other and no other futex ops.
+                *
+                * We should never be requeueing a futex_q with a pi_state,
+                * which is awaiting a futex_unlock_pi().
                 */
                if ((requeue_pi && !this->rt_waiter) ||
-                   (!requeue_pi && this->rt_waiter)) {
+                   (!requeue_pi && this->rt_waiter) ||
+                   this->pi_state) {
                        ret = -EINVAL;
                        break;
                }