| Message ID | 20190605154052.GA7571@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
| Series | [next] i40e/i40e_virtchnl_pf: Use struct_size() in kzalloc() | expand |
> -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On > Behalf Of Gustavo A. R. Silva > Sent: Wednesday, June 5, 2019 8:41 AM > To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; David S. Miller > <davem@davemloft.net> > Cc: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; linux- > kernel@vger.kernel.org > Subject: [Intel-wired-lan] [PATCH][next] i40e/i40e_virtchnl_pf: Use > struct_size() in kzalloc() > > 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 virtchnl_iwarp_qvlist_info { > ... > struct virtchnl_iwarp_qv_info qv_info[1]; }; > > size = sizeof(struct virtchnl_iwarp_qvlist_info) + (sizeof(struct > virtchnl_iwarp_qv_info) * count; instance = kzalloc(size, GFP_KERNEL); > > and > > struct virtchnl_vf_resource { > ... > struct virtchnl_vsi_resource vsi_res[1]; }; > > size = sizeof(struct virtchnl_vf_resource) + sizeof(struct > virtchnl_vsi_resource) * count; 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, qv_info, count), GFP_KERNEL); > > and > > instance = kzalloc(struct_size(instance, vsi_res, count), GFP_KERNEL); > > Notice that, in the first case above, 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> > --- > .../net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 15 ++++++--------- > 1 file changed, 6 insertions(+), 9 deletions(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c index 479bc60c8f71..1d6e65fc8a7e 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c +++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c @@ -440,7 +440,7 @@ static int i40e_config_iwarp_qvlist(struct i40e_vf *vf, struct virtchnl_iwarp_qv_info *qv_info; u32 v_idx, i, reg_idx, reg; u32 next_q_idx, next_q_type; - u32 msix_vf, size; + u32 msix_vf; int ret = 0; msix_vf = pf->hw.func_caps.num_msix_vectors_vf; @@ -454,11 +454,10 @@ static int i40e_config_iwarp_qvlist(struct i40e_vf *vf, goto err_out; } - size = sizeof(struct virtchnl_iwarp_qvlist_info) + - (sizeof(struct virtchnl_iwarp_qv_info) * - (qvlist_info->num_vectors - 1)); kfree(vf->qvlist_info); - vf->qvlist_info = kzalloc(size, GFP_KERNEL); + vf->qvlist_info = kzalloc(struct_size(vf->qvlist_info, qv_info, + qvlist_info->num_vectors - 1), + GFP_KERNEL); if (!vf->qvlist_info) { ret = -ENOMEM; goto err_out; @@ -1845,7 +1844,7 @@ static int i40e_vc_get_vf_resources_msg(struct i40e_vf *vf, u8 *msg) i40e_status aq_ret = 0; struct i40e_vsi *vsi; int num_vsis = 1; - int len = 0; + size_t len = 0; int ret; if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) { @@ -1853,9 +1852,7 @@ static int i40e_vc_get_vf_resources_msg(struct i40e_vf *vf, u8 *msg) goto err; } - len = (sizeof(struct virtchnl_vf_resource) + - sizeof(struct virtchnl_vsi_resource) * num_vsis); - + len = struct_size(vfres, vsi_res, num_vsis); vfres = kzalloc(len, GFP_KERNEL); if (!vfres) { aq_ret = I40E_ERR_NO_MEMORY;
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 virtchnl_iwarp_qvlist_info { ... struct virtchnl_iwarp_qv_info qv_info[1]; }; size = sizeof(struct virtchnl_iwarp_qvlist_info) + (sizeof(struct virtchnl_iwarp_qv_info) * count; instance = kzalloc(size, GFP_KERNEL); and struct virtchnl_vf_resource { ... struct virtchnl_vsi_resource vsi_res[1]; }; size = sizeof(struct virtchnl_vf_resource) + sizeof(struct virtchnl_vsi_resource) * count; 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, qv_info, count), GFP_KERNEL); and instance = kzalloc(struct_size(instance, vsi_res, count), GFP_KERNEL); Notice that, in the first case above, 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> --- .../net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)