From: Paul E. McKenney <paulmck@kernel.org>
Date: Sat, 10 Jul 2021 00:53:27 +0000 (-0700)
Subject: scftorture: Avoid NULL pointer exception on early exit
X-Git-Tag: accepted/tizen/unified/20230118.172025~6579^2^6~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=586e4d4193a653eef21f02b50dee89e2e4be208c;p=platform%2Fkernel%2Flinux-rpi.git

scftorture: Avoid NULL pointer exception on early exit

When scftorture finds an error in the module parameters controlling
the relative frequencies of smp_call_function*() variants, it takes an
early exit.  So early that it has not allocated memory to track the
kthreads running the test, which results in a segfault.  This commit
therefore checks for the existence of the memory before attempting
to stop the kthreads that would otherwise have been recorded in that
non-existent memory.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---

diff --git a/kernel/scftorture.c b/kernel/scftorture.c
index 5cf40e4..64a0828 100644
--- a/kernel/scftorture.c
+++ b/kernel/scftorture.c
@@ -513,7 +513,7 @@ static void scf_torture_cleanup(void)
 		return;
 
 	WRITE_ONCE(scfdone, true);
-	if (nthreads)
+	if (nthreads && scf_stats_p)
 		for (i = 0; i < nthreads; i++)
 			torture_stop_kthread("scftorture_invoker", scf_stats_p[i].task);
 	else