* [PATCH] rhashtable: use struct_size() in kvzalloc()
@ 2019-04-11 23:43 Gustavo A. R. Silva
2019-04-13 0:33 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2019-04-11 23:43 UTC (permalink / raw)
To: Thomas Graf, Herbert Xu; +Cc: netdev, linux-kernel, Gustavo A. R. Silva
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along with
memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kvzalloc(size, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kvzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
lib/rhashtable.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index a8583af43b59..9c84f5cef69c 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -175,8 +175,7 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
int i;
static struct lock_class_key __key;
- size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
- tbl = kvzalloc(size, gfp);
+ tbl = kvzalloc(struct_size(tbl, buckets, nbuckets), gfp);
size = nbuckets;
--
2.21.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] rhashtable: use struct_size() in kvzalloc()
2019-04-11 23:43 [PATCH] rhashtable: use struct_size() in kvzalloc() Gustavo A. R. Silva
@ 2019-04-13 0:33 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2019-04-13 0:33 UTC (permalink / raw)
To: gustavo; +Cc: tgraf, herbert, netdev, linux-kernel
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Thu, 11 Apr 2019 18:43:06 -0500
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along with
> memory for some number of elements for that array. For example:
>
> struct foo {
> int stuff;
> struct boo entry[];
> };
>
> size = sizeof(struct foo) + count * sizeof(struct boo);
> instance = kvzalloc(size, GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = kvzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Applied.
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