From: Paul E. McKenney <paulmck@kernel.org>
Date: Thu, 17 Sep 2020 17:37:10 +0000 (-0700)
Subject: refscale: Prevent hangs for invalid arguments
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=bc80d353b3f565138cda7e95ed4020e6e69360b2;p=linux.git

refscale: Prevent hangs for invalid arguments

If an refscale 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 ref_scale_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@kernel.org>
---

diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index fb5f20d9486a8..23ff36a66f979 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -658,7 +658,6 @@ ref_scale_init(void)
 		for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
 			pr_cont(" %s", scale_ops[i]->name);
 		pr_cont("\n");
-		WARN_ON(!IS_MODULE(CONFIG_RCU_REF_SCALE_TEST));
 		firsterr = -EINVAL;
 		cur_ops = NULL;
 		goto unwind;
@@ -718,6 +717,10 @@ ref_scale_init(void)
 unwind:
 	torture_init_end();
 	ref_scale_cleanup();
+	if (shutdown) {
+		WARN_ON(!IS_MODULE(CONFIG_RCU_REF_SCALE_TEST));
+		kernel_power_off();
+	}
 	return firsterr;
 }