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author | Thomas Gleixner <tglx@linutronix.de> | 2015-12-19 20:07:38 +0000 |
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committer | Luis Henriques <luis.henriques@canonical.com> | 2016-02-02 17:38:41 +0000 |
commit | c05e790e5c29d13593f9fd99073c800d80a87ed4 (patch) | |
tree | 2820afb0167fb24cd84f62d2e46355160f801b5c | |
parent | 1ab09128f5d43874dc3b4d661459e57ccb9eaed5 (diff) | |
download | linux-stable-c05e790e5c29d13593f9fd99073c800d80a87ed4.tar.gz linux-stable-c05e790e5c29d13593f9fd99073c800d80a87ed4.tar.bz2 linux-stable-c05e790e5c29d13593f9fd99073c800d80a87ed4.zip |
futex: Drop refcount if requeue_pi() acquired the rtmutex
commit fb75a4282d0d9a3c7c44d940582c2d226cf3acfb upstream.
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>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
-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 9fba3c706e2b..12b5f5264328 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2662,6 +2662,11 @@ 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 { |