[tip: core/rcu] scftorture: Check unexpected "switch" statement value

[tip-bot2 for Paul E. McKenney]

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

Commit-ID:     de77d4da54d10df97d265e7e99112bfc2fef7d4a
Gitweb:        https://git.kernel.org/tip/de77d4da54d10df97d265e7e99112bfc2fef7d4a
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Thu, 02 Jul 2020 12:15:37 -07:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 24 Aug 2020 18:38:37 -07:00

scftorture: Check unexpected "switch" statement value

This commit adds a "default" case to the switch statement in
scftorture_invoke_one() which contains a WARN_ON_ONCE() and an assignment
to ->scfc_out to suppress knock-on warnings.  These knock-on warnings
could otherwise cause the user to think that there was a memory-ordering
problem in smp_call_function() instead of a bug in scftorture.c itself.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/scftorture.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index 9180de7..d9c01c7 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -357,6 +357,10 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra
 		}
 		smp_call_function(scf_handler, scfcp, scfsp->scfs_wait);
 		break;
+	default:
+		WARN_ON_ONCE(1);
+		if (scfcp)
+			scfcp->scfc_out = true;
 	}
 	if (scfcp && scfsp->scfs_wait) {
 		if (WARN_ON_ONCE(!scfcp->scfc_out))