[obsolete] mm-slab-avoid-the-use-of-one-element-array-and-use-struct_size-helper.patch removed from -mm tree

[Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>]

The patch titled
     Subject: mm: slab: avoid the use of one-element array and use struct_size() helper
has been removed from the -mm tree.  Its filename was
     mm-slab-avoid-the-use-of-one-element-array-and-use-struct_size-helper.patch

This patch was dropped because it is obsolete

------------------------------------------------------
From: Qianli Zhao <zhaoqianli@xxxxxxxxxx>
Subject: mm: slab: avoid the use of one-element array and use struct_size() helper

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure.  Kernel code
should always use “flexible array members”[1] for these cases.  The
older style of one-element or zero-length arrays should no longer be
used[2].

Make use of the struct_size() helper instead of an open-coded version in
order to avoid any potential type mistakes.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Link: http://lkml.kernel.org/r/1596034214-15010-1-git-send-email-zhaoqianligood@xxxxxxxxx
Signed-off-by: Qianli Zhao <zhaoqianli@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/slab.h        |    2 +-
 mm/slab_common.c |    7 ++-----
 2 files changed, 3 insertions(+), 6 deletions(-)

--- a/mm/slab_common.c~mm-slab-avoid-the-use-of-one-element-array-and-use-struct_size-helper
+++ a/mm/slab_common.c
@@ -168,9 +168,7 @@ static int init_memcg_params(struct kmem
 	if (!memcg_nr_cache_ids)
 		return 0;
 
-	arr = kvzalloc(sizeof(struct memcg_cache_array) +
-		       memcg_nr_cache_ids * sizeof(void *),
-		       GFP_KERNEL);
+	arr = kvzalloc(struct_size(arr, entries, memcg_nr_cache_ids), GFP_KERNEL);
 	if (!arr)
 		return -ENOMEM;
 
@@ -201,8 +199,7 @@ static int update_memcg_params(struct km
 {
 	struct memcg_cache_array *old, *new;
 
-	new = kvzalloc(sizeof(struct memcg_cache_array) +
-		       new_array_size * sizeof(void *), GFP_KERNEL);
+	new = kvzalloc(struct_size(new, entries, new_array_size), GFP_KERNEL);
 	if (!new)
 		return -ENOMEM;
 
--- a/mm/slab.h~mm-slab-avoid-the-use-of-one-element-array-and-use-struct_size-helper
+++ a/mm/slab.h
@@ -34,7 +34,7 @@ struct kmem_cache {
 
 struct memcg_cache_array {
 	struct rcu_head rcu;
-	struct kmem_cache *entries[0];
+	struct kmem_cache *entries[];
 };
 
 /*
_

Patches currently in -mm which might be from zhaoqianli@xxxxxxxxxx are