| Message ID | 20190208034241.GA11858@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] mlxsw: spectrum_router: Use struct_size() in kzalloc() | expand |
Fri, Feb 08, 2019 at 04:42:41AM CET, gustavo@embeddedor.com wrote: >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 <gustavo@embeddedor.com> Acked-by: Jiri Pirko <jiri@mellanox.com>
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Thu, 7 Feb 2019 21:42:41 -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 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 <gustavo@embeddedor.com> Applied.
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index 230e1f6e192b..e3a3535f9f23 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -3813,13 +3813,11 @@ mlxsw_sp_nexthop4_group_create(struct mlxsw_sp *mlxsw_sp, struct fib_info *fi) struct mlxsw_sp_nexthop_group *nh_grp; struct mlxsw_sp_nexthop *nh; struct fib_nh *fib_nh; - size_t alloc_size; int i; int err; - alloc_size = sizeof(*nh_grp) + - fi->fib_nhs * sizeof(struct mlxsw_sp_nexthop); - nh_grp = kzalloc(alloc_size, GFP_KERNEL); + nh_grp = kzalloc(struct_size(nh_grp, nexthops, fi->fib_nhs), + GFP_KERNEL); if (!nh_grp) return ERR_PTR(-ENOMEM); nh_grp->priv = fi; @@ -5045,13 +5043,11 @@ mlxsw_sp_nexthop6_group_create(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_nexthop_group *nh_grp; struct mlxsw_sp_rt6 *mlxsw_sp_rt6; struct mlxsw_sp_nexthop *nh; - size_t alloc_size; int i = 0; int err; - alloc_size = sizeof(*nh_grp) + - fib6_entry->nrt6 * sizeof(struct mlxsw_sp_nexthop); - nh_grp = kzalloc(alloc_size, GFP_KERNEL); + nh_grp = kzalloc(struct_size(nh_grp, nexthops, fib6_entry->nrt6), + GFP_KERNEL); if (!nh_grp) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&nh_grp->fib_list);
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 <gustavo@embeddedor.com> --- .../net/ethernet/mellanox/mlxsw/spectrum_router.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)