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author | Thomas Gleixner <tglx@linutronix.de> | 2015-12-19 20:07:38 +0000 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2015-12-20 12:43:24 +0100 |
commit | fb75a4282d0d9a3c7c44d940582c2d226cf3acfb (patch) | |
tree | c81fbcdebe6531267922ca86dab5a74847bed6af /kernel/futex.c | |
parent | 2d142e599bf73ab70a3457e6947f86935245415e (diff) | |
download | lwn-fb75a4282d0d9a3c7c44d940582c2d226cf3acfb.tar.gz lwn-fb75a4282d0d9a3c7c44d940582c2d226cf3acfb.zip |
futex: Drop refcount if requeue_pi() acquired the rtmutex
If the proxy lock in the requeue loop acquires the rtmutex for a
waiter then it acquired also refcount on the pi_state related to the
futex, but the waiter side does not drop the reference count.
Add the missing free_pi_state() call.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <darren@dvhart.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Bhuvanesh_Surachari@mentor.com
Cc: Andy Lowe <Andy_Lowe@mentor.com>
Link: http://lkml.kernel.org/r/20151219200607.178132067@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Diffstat (limited to 'kernel/futex.c')
-rw-r--r-- | kernel/futex.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 684d7549825a..24fbc7765828 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2755,6 +2755,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, if (q.pi_state && (q.pi_state->owner != current)) { spin_lock(q.lock_ptr); ret = fixup_pi_state_owner(uaddr2, &q, current); + /* + * Drop the reference to the pi state which + * the requeue_pi() code acquired for us. + */ + free_pi_state(q.pi_state); spin_unlock(q.lock_ptr); } } else { |