Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH rcu 09/19] srcu: Use export for srcu_struct defined by DEFINE_STATIC_SRCU() | Date | Fri, 4 Feb 2022 15:38:52 -0800 |
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From: Alexander Aring <aahringo@redhat.com>
If an srcu_struct structure defined by tree SRCU's DEFINE_STATIC_SRCU() is used by a module, sparse will give the following diagnostic:
sparse: symbol '__srcu_struct_nodes_srcu' was not declared. Should it be static?
The problem is that a within-module DEFINE_STATIC_SRCU() must define a non-static srcu_struct because it is exported by referencing it in a special '__section("___srcu_struct_ptrs")'. This reference is needed so that module load and unloading can invoke init_srcu_struct() and cleanup_srcu_struct(), respectively. Unfortunately, sparse is unaware of '__section("___srcu_struct_ptrs")', resulting in the above false-positive diagnostic. To avoid this false positive, this commit therefore creates a prototype of the srcu_struct with an "extern" keyword.
Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- include/linux/srcutree.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 8501b6b459411..44e998643f483 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -131,6 +131,7 @@ struct srcu_struct { #ifdef MODULE # define __DEFINE_SRCU(name, is_static) \ is_static struct srcu_struct name; \ + extern struct srcu_struct * const __srcu_struct_##name; \ struct srcu_struct * const __srcu_struct_##name \ __section("___srcu_struct_ptrs") = &name #else -- 2.31.1.189.g2e36527f23
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