Commit e6fb1fc1 authored Feb 07, 2016 by Artem Savkov Committed by Paul E. McKenney Mar 31, 2016

rcuperf: Do not wake up shutdown wait queue if "shutdown" is false.

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>

parent dba6f1ba

kernel/rcu/rcuperf.c

+4 −2

Original line number	Original line	Diff line number	Diff line
	@@ -423,10 +423,12 @@ rcu_perf_writer(void *arg)
	b_rcu_perf_writer_finished =		b_rcu_perf_writer_finished =
	cur_ops->completed();		cur_ops->completed();
	}		}
			if (shutdown) {
	smp_mb(); /* Assign before wake. */		smp_mb(); /* Assign before wake. */
	wake_up(&shutdown_wq);		wake_up(&shutdown_wq);
	}		}
	}		}
			}
	if (done && !alldone &&		if (done && !alldone &&
	atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters)		atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters)
	alldone = true;		alldone = true;