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 <gust...@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
