| Message ID | 20190208035537.GA12318@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] fm10k: use struct_size() in kzalloc() | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Thu, 7 Feb 2019 21:55:37 -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 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.
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c index 6fd15a734324..5a0419421511 100644 --- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c @@ -1603,14 +1603,12 @@ static int fm10k_alloc_q_vector(struct fm10k_intfc *interface, { struct fm10k_q_vector *q_vector; struct fm10k_ring *ring; - int ring_count, size; + int ring_count; ring_count = txr_count + rxr_count; - size = sizeof(struct fm10k_q_vector) + - (sizeof(struct fm10k_ring) * ring_count); /* allocate q_vector and rings */ - q_vector = kzalloc(size, GFP_KERNEL); + q_vector = kzalloc(struct_size(q_vector, ring, ring_count), GFP_KERNEL); if (!q_vector) return -ENOMEM;
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 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/intel/fm10k/fm10k_main.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)