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 = kvzalloc(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 = kvzalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gust...@embeddedor.com> --- drivers/net/ethernet/chelsio/cxgb4/smt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb4/smt.c b/drivers/net/ethernet/chelsio/cxgb4/smt.c index 7b2207a2a130..eaf1fb74689c 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/smt.c +++ b/drivers/net/ethernet/chelsio/cxgb4/smt.c @@ -47,8 +47,7 @@ struct smt_data *t4_init_smt(void) smt_size = SMT_SIZE; - s = kvzalloc(sizeof(*s) + smt_size * sizeof(struct smt_entry), - GFP_KERNEL); + s = kvzalloc(struct_size(s, smtab, smt_size), GFP_KERNEL); if (!s) return NULL; s->smt_size = smt_size; -- 2.20.1