percpu: Make __verify_pcu_ptr handle per cpu pointers to arrays
__verify_pcpu_ptr() will cause a compilation failure if the type of the
pointer is a pointer to a fixed array of objects. Adding zero to the
pointer converts the type of pointer to that pointing to a single
object of the array.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h
index 27ef6b1..57e890a 100644
--- a/include/linux/percpu-defs.h
+++ b/include/linux/percpu-defs.h
@@ -22,9 +22,12 @@
* Macro which verifies @ptr is a percpu pointer without evaluating
* @ptr. This is to be used in percpu accessors to verify that the
* input parameter is a percpu pointer.
+ *
+ * + 0 is required in order to convert the pointer type from a
+ * potential array type to a pointer to a single item of the array.
*/
#define __verify_pcpu_ptr(ptr) do { \
- const void __percpu *__vpp_verify = (typeof(ptr))NULL; \
+ const void __percpu *__vpp_verify = (typeof((ptr) + 0))NULL; \
(void)__vpp_verify; \
} while (0)