[tip: core/rcu] rcu: Introduce kfree_rcu() single-argument macro

[tip: core/rcu] rcu: Introduce kfree_rcu() single-argument macro

[tip-bot2 for Uladzislau Rezki (Sony)]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     5130b8fd06901c1b3a4bd0d0f5c5ea99b2b0a6f0
Gitweb:        https://git.kernel.org/tip/5130b8fd06901c1b3a4bd0d0f5c5ea99b2b0a6f0
Author:        Uladzislau Rezki (Sony) <urezki@gmail.com>
AuthorDate:    Fri, 20 Nov 2020 12:49:16 +01:00
Committer:     Paul E. McKenney <paulmck@kernel.org>
CommitterDate: Mon, 04 Jan 2021 13:42:04 -08:00

rcu: Introduce kfree_rcu() single-argument macro

There is a kvfree_rcu() single argument macro that handles pointers
returned by kvmalloc(). Even though it also handles pointer returned by
kmalloc(), readability suffers.

This commit therefore updates the kfree_rcu() macro to explicitly pair
with kmalloc(), thus improving readability.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 include/linux/rcupdate.h | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index de08264..b95373e 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -851,8 +851,9 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
 
 /**
  * kfree_rcu() - kfree an object after a grace period.
- * @ptr:	pointer to kfree
- * @rhf:	the name of the struct rcu_head within the type of @ptr.
+ * @ptr: pointer to kfree for both single- and double-argument invocations.
+ * @rhf: the name of the struct rcu_head within the type of @ptr,
+ *       but only for double-argument invocations.
  *
  * Many rcu callbacks functions just call kfree() on the base structure.
  * These functions are trivial, but their size adds up, and furthermore
@@ -875,13 +876,7 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
  * The BUILD_BUG_ON check must not involve any function calls, hence the
  * checks are done in macros here.
  */
-#define kfree_rcu(ptr, rhf)						\
-do {									\
-	typeof (ptr) ___p = (ptr);					\
-									\
-	if (___p)							\
-		__kvfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
-} while (0)
+#define kfree_rcu kvfree_rcu
 
 /**
  * kvfree_rcu() - kvfree an object after a grace period.
@@ -913,7 +908,14 @@ do {									\
 	kvfree_rcu_arg_2, kvfree_rcu_arg_1)(__VA_ARGS__)
 
 #define KVFREE_GET_MACRO(_1, _2, NAME, ...) NAME
-#define kvfree_rcu_arg_2(ptr, rhf) kfree_rcu(ptr, rhf)
+#define kvfree_rcu_arg_2(ptr, rhf)					\
+do {									\
+	typeof (ptr) ___p = (ptr);					\
+									\
+	if (___p)							\
+		__kvfree_rcu(&((___p)->rhf), offsetof(typeof(*(ptr)), rhf)); \
+} while (0)
+
 #define kvfree_rcu_arg_1(ptr)					\
 do {								\
 	typeof(ptr) ___p = (ptr);				\