scftorture: Check unexpected "switch" statement value

paulmckrcu · paulmckrcu · commit de77d4da54d1 · 2020-08-24T18:38:37.000-07:00
This commit adds a "default" case to the switch statement in
scftorture_invoke_one() which contains a WARN_ON_ONCE() and an assignment
to -&gt;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 &lt;paulmck@kernel.org&gt;
diff --git 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))

Original file line number	Diff line number	Diff line change
`@@ -357,6 +357,10 @@ static void scftorture_invoke_one(struct scf_statistics *scfp, struct torture_ra`
`357`	`357`	`}`
`358`	`358`	`smp_call_function(scf_handler, scfcp, scfsp->scfs_wait);`
`359`	`359`	`break;`
	`360`	`+ default:`
	`361`	`+ WARN_ON_ONCE(1);`
	`362`	`+ if (scfcp)`
	`363`	`+ scfcp->scfc_out = true;`
`360`	`364`	`}`
`361`	`365`	`if (scfcp && scfsp->scfs_wait) {`
`362`	`366`	`if (WARN_ON_ONCE(!scfcp->scfc_out))`