[tip: core/rcu] srcu: Add KCSAN stubs

[tip: core/rcu] srcu: Add KCSAN stubs

[tip-bot2 for Paul E. McKenney]

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

Commit-ID:     4f58820fd710e0563e22420c07c03c5ccec948bf
Gitweb:        https://git.kernel.org/tip/4f58820fd710e0563e22420c07c03c5ccec948bf
Author:        Paul E. McKenney <paulmck@kernel.org>
AuthorDate:    Mon, 13 Apr 2020 16:33:01 -07:00
Committer:     Paul E. McKenney <paulmck@kernel.org>
CommitterDate: Mon, 27 Apr 2020 11:01:15 -07:00

srcu: Add KCSAN stubs

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@kernel.org>
---
 kernel/rcu/srcutree.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 0c71505..ba2b751 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -29,6 +29,19 @@
 #include "rcu.h"
 #include "rcu_segcblist.h"
 
+#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
+
 /* Holdoff in nanoseconds for auto-expediting. */
 #define DEFAULT_SRCU_EXP_HOLDOFF (25 * 1000)
 static ulong exp_holdoff = DEFAULT_SRCU_EXP_HOLDOFF;