diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2007-06-08 10:29:29 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-08-04 09:10:23 -0700 |
| commit | 8e6a96266ae4617bc14faa1155fc35d1319fa431 (patch) | |
| tree | f921a322439faaa9a1c1c4728cf1f7e9f28451f4 | |
| parent | 21e3424ee9ce6760b03ed3bfc7a26e002b9de0ed (diff) | |
rt-mutex: Fix chain walk early wakeup bug
Alexey Kuznetsov found some problems in the pi-futex code.
One of the root causes is:
When a wakeup happens, we do not to stop the chain walk so we
we follow a non existing locking chain.
Drop out when this happens.
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | kernel/rtmutex.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 21ebe7612f8..17d28ce2030 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -212,6 +212,19 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, if (!waiter || !waiter->task) goto out_unlock_pi; + /* + * Check the orig_waiter state. After we dropped the locks, + * the previous owner of the lock might have released the lock + * and made us the pending owner: + */ + if (orig_waiter && !orig_waiter->task) + goto out_unlock_pi; + + /* + * Drop out, when the task has no waiters. Note, + * top_waiter can be NULL, when we are in the deboosting + * mode! + */ if (top_waiter && (!task_has_pi_waiters(task) || top_waiter != task_top_pi_waiter(task))) goto out_unlock_pi; |