* [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc()
@ 2019-02-25 19:01 Gustavo A. R. Silva
2019-02-25 19:17 ` Ido Schimmel
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2019-02-25 19:01 UTC (permalink / raw)
To: Jiri Pirko, Ido Schimmel, David S. Miller
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 = kzalloc(size, GFP_KERNEL)
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
Notice that, in this case, variable alloc_size is not necessary, hence
it is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c b/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c
index df78d23b3ec3..cb3e663b1d37 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.c
@@ -236,12 +236,10 @@ mlxsw_afk_key_info_create(struct mlxsw_afk *mlxsw_afk,
struct mlxsw_afk_element_usage *elusage)
{
struct mlxsw_afk_key_info *key_info;
- size_t alloc_size;
int err;
- alloc_size = sizeof(*key_info) +
- sizeof(key_info->blocks[0]) * mlxsw_afk->max_blocks;
- key_info = kzalloc(alloc_size, GFP_KERNEL);
+ key_info = kzalloc(struct_size(key_info, blocks, mlxsw_afk->max_blocks),
+ GFP_KERNEL);
if (!key_info)
return ERR_PTR(-ENOMEM);
err = mlxsw_afk_picker(mlxsw_afk, key_info, elusage);
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc()
2019-02-25 19:01 [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc() Gustavo A. R. Silva
@ 2019-02-25 19:17 ` Ido Schimmel
2019-02-25 22:18 ` David Miller
2019-02-26 8:54 ` Jiri Pirko
2 siblings, 0 replies; 4+ messages in thread
From: Ido Schimmel @ 2019-02-25 19:17 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Jiri Pirko, Ido Schimmel, David S. Miller, netdev, linux-kernel
On Mon, Feb 25, 2019 at 01:01:32PM -0600, Gustavo A. R. Silva wrote:
> 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 = kzalloc(size, GFP_KERNEL)
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
>
> Notice that, in this case, variable alloc_size is not necessary, hence
> it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Thanks
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc()
2019-02-25 19:01 [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc() Gustavo A. R. Silva
2019-02-25 19:17 ` Ido Schimmel
@ 2019-02-25 22:18 ` David Miller
2019-02-26 8:54 ` Jiri Pirko
2 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2019-02-25 22:18 UTC (permalink / raw)
To: gustavo; +Cc: jiri, idosch, netdev, linux-kernel
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Mon, 25 Feb 2019 13:01:32 -0600
> 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 = kzalloc(size, GFP_KERNEL)
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
>
> Notice that, in this case, variable alloc_size is not necessary, hence
> it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Applied, thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc()
2019-02-25 19:01 [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc() Gustavo A. R. Silva
2019-02-25 19:17 ` Ido Schimmel
2019-02-25 22:18 ` David Miller
@ 2019-02-26 8:54 ` Jiri Pirko
2 siblings, 0 replies; 4+ messages in thread
From: Jiri Pirko @ 2019-02-26 8:54 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Jiri Pirko, Ido Schimmel, David S. Miller, netdev, linux-kernel
Mon, Feb 25, 2019 at 08:01:32PM CET, gustavo@embeddedor.com wrote:
>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 = kzalloc(size, GFP_KERNEL)
>
>Instead of leaving these open-coded and prone to type mistakes, we can
>now use the new struct_size() helper:
>
>instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
>
>Notice that, in this case, variable alloc_size is not necessary, hence
>it is removed.
>
>This code was detected with the help of Coccinelle.
>
>Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2019-02-25 19:01 [PATCH net-next] mlxsw: spectrum: acl: Use struct_size() in kzalloc() Gustavo A. R. Silva
2019-02-25 19:17 ` Ido Schimmel
2019-02-25 22:18 ` David Miller
2019-02-26 8:54 ` Jiri Pirko
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