[Intel-wired-lan] [PATCH][next] i40e/i40e_virtchnl_pf: Use struct_size() in kzalloc()
Gustavo A. R. Silva
gustavo at embeddedor.com
Wed Jun 5 15:40:52 UTC 2019
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 at embeddedor.com>
---
.../net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
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;
--
2.21.0
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