[PATCH for-v7.5 3/5] rcu: assert static storage for RCU sync and SRCU definitions

[Joel Fernandes <jfern@kernel.org>]

From: Yury Norov <ynorov@nvidia.com>

DEFINE_RCU_SYNC() contains a statically initialized wait queue. SRCU
static definitions similarly rely on persistent lockdep keys and, in
Tiny SRCU, a statically initialized work item.

Add ASSERT_STATIC_STORAGE() to DEFINE_RCU_SYNC(), both Tree SRCU
__DEFINE_SRCU() variants and Tiny SRCU's common DEFINE_SRCU() declaration.
This covers the non-static FAST and FAST_UPDOWN wrappers too. Tiny SRCU's
explicitly static declarations already enforce the required duration.
The existing per-CPU restrictions on Tree SRCU declarations still apply.

Assisted-by: OpenAI Codex
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: Joel Fernandes <jfern@kernel.org>
Signed-off-by: Joel Fernandes <jfern@kernel.org>
---
 include/linux/rcu_sync.h | 4 +++-
 include/linux/srcutiny.h | 4 +++-
 include/linux/srcutree.h | 7 +++++--
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/include/linux/rcu_sync.h b/include/linux/rcu_sync.h
index 3860dbb9107a..c10b6d30561a 100644
--- a/include/linux/rcu_sync.h
+++ b/include/linux/rcu_sync.h
@@ -10,6 +10,7 @@
 #ifndef _LINUX_RCU_SYNC_H_
 #define _LINUX_RCU_SYNC_H_
 
+#include <linux/compiler.h>
 #include <linux/wait.h>
 #include <linux/rcupdate.h>
 
@@ -48,6 +49,7 @@ extern void rcu_sync_dtor(struct rcu_sync *);
 	}
 
 #define	DEFINE_RCU_SYNC(name)	\
-	struct rcu_sync name = __RCU_SYNC_INITIALIZER(name)
+	struct rcu_sync name = __RCU_SYNC_INITIALIZER(name);	\
+	ASSERT_STATIC_STORAGE(name)
 
 #endif /* _LINUX_RCU_SYNC_H_ */
diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h
index 47a368f945e3..82901b45c9e1 100644
--- a/include/linux/srcutiny.h
+++ b/include/linux/srcutiny.h
@@ -11,6 +11,7 @@
 #ifndef _LINUX_SRCU_TINY_H
 #define _LINUX_SRCU_TINY_H
 
+#include <linux/compiler.h>
 #include <linux/irq_work_types.h>
 #include <linux/llist.h>
 #include <linux/swait.h>
@@ -56,7 +57,8 @@ void srcu_defer_drain(struct irq_work *irq_work);
  * Tree SRCU, which needs some per-CPU data.
  */
 #define DEFINE_SRCU(name) \
-	struct srcu_struct name = __SRCU_STRUCT_INIT(name, name, name, name)
+	struct srcu_struct name = __SRCU_STRUCT_INIT(name, name, name, name);	\
+	ASSERT_STATIC_STORAGE(name)
 #define DEFINE_STATIC_SRCU(name) \
 	static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name, name, name)
 #define DEFINE_SRCU_FAST(name) DEFINE_SRCU(name)
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h
index 93b76e543894..332d228da270 100644
--- a/include/linux/srcutree.h
+++ b/include/linux/srcutree.h
@@ -11,6 +11,7 @@
 #ifndef _LINUX_SRCU_TREE_H
 #define _LINUX_SRCU_TREE_H
 
+#include <linux/compiler.h>
 #include <linux/rcu_node_tree.h>
 #include <linux/completion.h>
 #include <linux/irq_work_types.h>
@@ -228,13 +229,15 @@ struct srcu_struct {
 								      fast);			\
 	extern struct srcu_struct * const __srcu_struct_##name;					\
 	struct srcu_struct * const __srcu_struct_##name						\
-		__section("___srcu_struct_ptrs") = &name
+		__section("___srcu_struct_ptrs") = &name;					\
+	ASSERT_STATIC_STORAGE(name)
 #else
 # define __DEFINE_SRCU(name, fast, is_static)							\
 	static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data);				\
 	static struct srcu_usage name##_srcu_usage = __SRCU_USAGE_INIT(name##_srcu_usage);	\
 	is_static struct srcu_struct name =							\
-		__SRCU_STRUCT_INIT(name, name##_srcu_usage, name##_srcu_data, fast)
+		__SRCU_STRUCT_INIT(name, name##_srcu_usage, name##_srcu_data, fast);		\
+	ASSERT_STATIC_STORAGE(name)
 #endif
 #define DEFINE_SRCU(name)		__DEFINE_SRCU(name, 0, /* !static */)
 #define DEFINE_STATIC_SRCU(name)	__DEFINE_SRCU(name, 0, static)
-- 
2.54.0