| Message ID | 20190208042258.GA32468@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] ixgbe: Use struct_size() helper | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Thu, 7 Feb 2019 22:22:58 -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/ixgbe/ixgbe_lib.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c index 62e6499e4146..cc3196ae5aea 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c @@ -836,12 +836,10 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter, struct ixgbe_ring *ring; int node = NUMA_NO_NODE; int cpu = -1; - int ring_count, size; + int ring_count; u8 tcs = adapter->hw_tcs; ring_count = txr_count + rxr_count + xdp_count; - size = sizeof(struct ixgbe_q_vector) + - (sizeof(struct ixgbe_ring) * ring_count); /* customize cpu for Flow Director mapping */ if ((tcs <= 1) && !(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)) { @@ -855,9 +853,11 @@ static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter, } /* allocate q_vector and rings */ - q_vector = kzalloc_node(size, GFP_KERNEL, node); + q_vector = kzalloc_node(struct_size(q_vector, ring, ring_count), + GFP_KERNEL, node); if (!q_vector) - 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/ixgbe/ixgbe_lib.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)