[tip: core/rcu] rcu: Add KCSAN stubs to update.c

[tip-bot2 for Paul E. McKenney]

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

Commit-ID:     c76e7e0bce10876e6b08ac2ce8af5ef7cba684ff
Gitweb:        https://git.kernel.org/tip/c76e7e0bce10876e6b08ac2ce8af5ef7cba684ff
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Tue, 14 Apr 2020 10:19:02 -07:00
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Mon, 27 Apr 2020 11:03:50 -07:00

rcu: Add KCSAN stubs to update.c

This commit adds stubs for KCSAN's data_race(), ASSERT_EXCLUSIVE_WRITER(),
and ASSERT_EXCLUSIVE_ACCESS() macros to allow code using these macros
to move ahead.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
 kernel/rcu/update.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 28a8bdc..74a698a 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -51,6 +51,19 @@
 #endif
 #define MODULE_PARAM_PREFIX "rcupdate."
 
+#ifndef data_race
+#define data_race(expr)							\
+	({								\
+		expr;							\
+	})
+#endif
+#ifndef ASSERT_EXCLUSIVE_WRITER
+#define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0)
+#endif
+#ifndef ASSERT_EXCLUSIVE_ACCESS
+#define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0)
+#endif
+
 #ifndef CONFIG_TINY_RCU
 module_param(rcu_expedited, int, 0);
 module_param(rcu_normal, int, 0);