irda: irttp: fix memory leak in irttp_open_tsap() error path

[~andy/linux] / kernel / futex.c

diff --git a/kernel/futex.c b/kernel/futex.c
index 3717e7b306e08c0e8c2d3a66219c3cae13176d99..20ef219bbe9b76b3d54e6b501366f15cd97c464a 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -716,7 +716,7 @@ static int futex_lock_pi_atomic(u32 __user *uaddr, struct futex_hash_bucket *hb,
                                struct futex_pi_state **ps,
                                struct task_struct *task, int set_waiters)
 {
-       int lock_taken, ret, ownerdied = 0;
+       int lock_taken, ret, force_take = 0;
        u32 uval, newval, curval, vpid = task_pid_vnr(task);
 
 retry:
@@ -755,17 +755,15 @@ retry:
        newval = curval | FUTEX_WAITERS;
 
        /*
-        * There are two cases, where a futex might have no owner (the
-        * owner TID is 0): OWNER_DIED. We take over the futex in this
-        * case. We also do an unconditional take over, when the owner
-        * of the futex died.
-        *
-        * This is safe as we are protected by the hash bucket lock !
+        * Should we force take the futex? See below.
         */
-       if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
-               /* Keep the OWNER_DIED bit */
+       if (unlikely(force_take)) {
+               /*
+                * Keep the OWNER_DIED and the WAITERS bit and set the
+                * new TID value.
+                */
                newval = (curval & ~FUTEX_TID_MASK) | vpid;
-               ownerdied = 0;
+               force_take = 0;
                lock_taken = 1;
        }
 
@@ -775,7 +773,7 @@ retry:
                goto retry;
 
        /*
-        * We took the lock due to owner died take over.
+        * We took the lock due to forced take over.
         */
        if (unlikely(lock_taken))
                return 1;
@@ -790,20 +788,25 @@ retry:
                switch (ret) {
                case -ESRCH:
                        /*
-                        * No owner found for this futex. Check if the
-                        * OWNER_DIED bit is set to figure out whether
-                        * this is a robust futex or not.
+                        * We failed to find an owner for this
+                        * futex. So we have no pi_state to block
+                        * on. This can happen in two cases:
+                        *
+                        * 1) The owner died
+                        * 2) A stale FUTEX_WAITERS bit
+                        *
+                        * Re-read the futex value.
                         */
                        if (get_futex_value_locked(&curval, uaddr))
                                return -EFAULT;
 
                        /*
-                        * We simply start over in case of a robust
-                        * futex. The code above will take the futex
-                        * and return happy.
+                        * If the owner died or we have a stale
+                        * WAITERS bit the owner TID in the user space
+                        * futex is 0.
                         */
-                       if (curval & FUTEX_OWNER_DIED) {
-                               ownerdied = 1;
+                       if (!(curval & FUTEX_TID_MASK)) {
+                               force_take = 1;
                                goto retry;
                        }
                default: