Messages in this thread Patch in this message | | | Date | Thu, 12 Mar 2015 15:13:24 -0400 | From | Steven Rostedt <> | Subject | [PATCH RT 17/39] rtmutex.c: Fix incorrect waiter check |
| |
3.14.34-rt32-rc1 stable review patch. If anyone has any objections, please let me know.
------------------
From: Brad Mouring <bmouring@ni.com>
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"
Signed-off-by: Brad Mouring <brad.mouring@ni.com> Reported-by: Ben Shelton <ben.shelton@ni.com> Reviewed-by: T Makphaibulchoke <tmac@hp.com> Tested-by: T Makphaibulchoke <tmac@hp.com> Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- 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 ec72272ab73a..74a824523d3a 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -361,7 +361,8 @@ 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; } /* -- 2.1.4
| |