rcu: Add a gcc-style structure initializer for RCU pointers
RCU_INIT_POINTER() returns a value that is never used, and which should
be abolished due to terminal ugliness:
q = RCU_INIT_POINTER(global_p, p);
However, there are two uses that cannot be handled by a do-while
formulation because they do gcc-style initialization:
RCU_INIT_POINTER(.real_cred, &init_cred),
RCU_INIT_POINTER(.cred, &init_cred),
This usage is clever, but not necessarily the nicest approach.
This commit therefore creates an RCU_POINTER_INITIALIZER() macro that
is specifically designed for gcc-style initialization.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 9cac722..ffe24c0 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -905,6 +905,14 @@
#define RCU_INIT_POINTER(p, v) \
p = (typeof(*v) __force __rcu *)(v)
+/**
+ * RCU_POINTER_INITIALIZER() - statically initialize an RCU protected pointer
+ *
+ * GCC-style initialization for an RCU-protected pointer in a structure field.
+ */
+#define RCU_POINTER_INITIALIZER(p, v) \
+ .p = (typeof(*v) __force __rcu *)(v)
+
static __always_inline bool __is_kfree_rcu_offset(unsigned long offset)
{
return offset < 4096;