[tip: core/rcu] locktorture: Prevent hangs for invalid arguments

[tip-bot2 for Paul E. McKenney]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     6b74fa0a776e3715d385b23d29db469179c825b0
Gitweb:        https://git.kernel.org/tip/6b74fa0a776e3715d385b23d29db469179c825b0
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Fri, 18 Sep 2020 11:18:06 -07:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Fri, 06 Nov 2020 17:13:53 -08:00

locktorture: Prevent hangs for invalid arguments

If an locktorture torture-test run is given a bad kvm.sh argument, the
test will complain to the console, which is good.  What is bad is that
from the user's perspective, it will just hang for the time specified
by the --duration argument.  This commit therefore forces an immediate
kernel shutdown if a lock_torture_init()-time error occurs, thus avoiding
the appearance of a hang.  It also forces a console splat in this case
to clearly indicate the presence of an error.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/locking/locktorture.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 046ea2d..79fbd97 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -29,6 +29,7 @@
 #include <linux/slab.h>
 #include <linux/percpu-rwsem.h>
 #include <linux/torture.h>
+#include <linux/reboot.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@xxxxxxxxxxxxx>");
@@ -1041,6 +1042,10 @@ static int __init lock_torture_init(void)
 unwind:
 	torture_init_end();
 	lock_torture_cleanup();
+	if (shutdown_secs) {
+		WARN_ON(!IS_MODULE(CONFIG_LOCK_TORTURE_TEST));
+		kernel_power_off();
+	}
 	return firsterr;
 }