Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 14/24] rcuperf: Do not wake up shutdown wait queue if "shutdown" is false. | Date | Tue, 12 Apr 2016 08:43:47 -0700 |
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From: Artem Savkov <artem.savkov@gmail.com>
After finishing its tests rcuperf tries to wake up shutdown_wq even if "shutdown" param is set to false, resulting in a wake_up() call on an unitialized wait_queue_head_t which leads to "BUG: spinlock bad magic" and "BUG: unable to handle kernel NULL pointer dereference".
Fix by checking "shutdown" param before waking up the queue.
Signed-off-by: Artem Savkov <artem.savkov@gmail.com> --- kernel/rcu/rcuperf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index 4c0572859ff0..3cee0d8393ed 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -423,8 +423,10 @@ rcu_perf_writer(void *arg) b_rcu_perf_writer_finished = cur_ops->completed(); } - smp_mb(); /* Assign before wake. */ - wake_up(&shutdown_wq); + if (shutdown) { + smp_mb(); /* Assign before wake. */ + wake_up(&shutdown_wq); + } } } if (done && !alldone && -- 2.5.2
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