From: Alexander Aring Date: Wed, 26 Jan 2022 15:03:54 +0000 (-0500) Subject: srcu: Use export for srcu_struct defined by DEFINE_STATIC_SRCU() X-Git-Tag: v5.19-rc1~252^2~1^5~9 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=db8f1471c61336477e2bf74dcb00e67d650e6dea;p=thirdparty%2Fkernel%2Flinux.git srcu: Use export for srcu_struct defined by DEFINE_STATIC_SRCU() 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 Signed-off-by: Paul E. McKenney --- 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