On Wed, 14 Jan 2015 15:11:38 -0600
"Brad Mouring" <bmouring@xxxxxx> wrote:
> In task_blocks_on_lock, there's a null check on pi_blocked_on
> of the task_struct. This pointer can encode the fact that the
> task that contains the pointer is waking (preventing requeuing)
> and therefore is non-null. Use the inline function to avoid
> dereferencing an invalid "pointer"
Yep, this looks legit. I can apply it to the series I maintain.
-- Steve
>
> Signed-off-by: Brad Mouring <brad.mouring@xxxxxx>
> Reported-by: Ben Shelton <ben.shelton@xxxxxx>
> Reviewed-by: T Makphaibulchoke <tmac@xxxxxx>
> Tested-by: T Makphaibulchoke <tmac@xxxxxx>
> ---
> kernel/locking/rtmutex.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
> index 6c40660..535321e 100644
> --- a/kernel/locking/rtmutex.c
> +++ b/kernel/locking/rtmutex.c
> @@ -335,7 +335,8 @@ int max_lock_depth = 1024;
>
> static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
> {
> - return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
> + return rt_mutex_real_waiter(p->pi_blocked_on) ?
> + p->pi_blocked_on->lock : 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
