Re: [PATCH 16/17] rcu: assert static storage for RCU sync and SRCU definitions
flat view
From: Joel Fernandes <joelagnelf@nvidia.com>
Date: 2026-10-07 18:41:19
Also in:
linux-fsdevel, linux-mm, linux-rt-devel, lkml, llvm, netdev, rcu, virtualization
On Mon, Sep 14, 2026 at 11:13:31PM -0400, Yury Norov wrote:
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 <redacted>
All the changes make sense to me. I'm ok with carrying this for -rcu 7.5 unless you want to take it. Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> thanks, Joel Fernandes
quoted hunk ↗ jump to hunk
--- 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 fbcf13bc12d1..40b592b4e2d8 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/swait.h>@@ -48,7 +49,8 @@ void srcu_tiny_irq_work(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 75e54e4f963f..8bea8044230a 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>@@ -217,13 +218,15 @@ 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, /* not static */) #define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, 0, static)-- 2.53.0