On Fri, 2010-07-09 at 15:32 -0700, Darren Hart wrote:
> If the pi_blocked_on variable is NULL, the subsequent WARN_ON's
> will cause an OOPS. Only perform the susequent checks if
> pi_blocked_on is valid.
>
> Signed-off-by: Darren Hart <dvhltc@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> Cc: John Kacur <jkacur@xxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Mike Galbraith <efault@xxxxxx>
> ---
> kernel/rtmutex.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
> index 23dd443..baac7d9 100644
> --- a/kernel/rtmutex.c
> +++ b/kernel/rtmutex.c
> @@ -579,9 +579,10 @@ static void wakeup_next_waiter(struct rt_mutex *lock, int savestate)
>
> raw_spin_lock(&pendowner->pi_lock);
>
> - WARN_ON(!pendowner->pi_blocked_on);
> - WARN_ON(pendowner->pi_blocked_on != waiter);
> - WARN_ON(pendowner->pi_blocked_on->lock != lock);
> + if (!WARN_ON(!pendowner->pi_blocked_on)) {
> + WARN_ON(pendowner->pi_blocked_on != waiter);
The above actually has no issue if the pi_blocked_on is NULL.
The below, well yeah.
-- Steve
> + WARN_ON(pendowner->pi_blocked_on->lock != lock);
> + }
>
> pendowner->pi_blocked_on = NULL;
>
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
