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[];
};

instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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);

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gust...@embeddedor.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c 
b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c
index fb1c48c698f2..9019548d731b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c
@@ -267,8 +267,8 @@ mlxsw_sp_nve_mc_record_create(struct mlxsw_sp *mlxsw_sp,
        struct mlxsw_sp_nve_mc_record *mc_record;
        int err;
 
-       mc_record = kzalloc(sizeof(*mc_record) + num_max_entries *
-                           sizeof(struct mlxsw_sp_nve_mc_entry), GFP_KERNEL);
+       mc_record = kzalloc(struct_size(mc_record, entries, num_max_entries),
+                           GFP_KERNEL);
        if (!mc_record)
                return ERR_PTR(-ENOMEM);
 
-- 
2.20.1

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