[tip: core/rcu] kcsan: selftest: Ensure that address is at least PAGE_SIZE

[tip-bot2 for Marco Elver]

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

Commit-ID:     4761612ffe3c1655e58f1ef9cf867c6f67d46fe2
Gitweb:        https://git.kernel.org/tip/4761612ffe3c1655e58f1ef9cf867c6f67d46fe2
Author:        Marco Elver <elver@xxxxxxxxxx>
AuthorDate:    Thu, 22 Oct 2020 13:45:52 +02:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 02 Nov 2020 17:08:50 -08:00

kcsan: selftest: Ensure that address is at least PAGE_SIZE

In preparation of supporting only addresses not within the NULL page,
change the selftest to never use addresses that are less than PAGE_SIZE.

Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/kcsan/selftest.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/kcsan/selftest.c b/kernel/kcsan/selftest.c
index d98bc20..9014a3a 100644
--- a/kernel/kcsan/selftest.c
+++ b/kernel/kcsan/selftest.c
@@ -33,6 +33,9 @@ static bool test_encode_decode(void)
 		unsigned long addr;
 
 		prandom_bytes(&addr, sizeof(addr));
+		if (addr < PAGE_SIZE)
+			addr = PAGE_SIZE;
+
 		if (WARN_ON(!check_encodable(addr, size)))
 			return false;