There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Refactor the code according to the use of a flexible-array member in struct
virtchnl_tc_info instead of one-element array, and use the flex_array_size()
helper.
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/ethernet/intel/iavf/iavf_virtchnl.c | 2 +-
include/linux/avf/virtchnl.h | 7 +++----
2 files changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
index 123a737f6955..cf2ac577a96f 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_virtchnl.c
@@ -1021,7 +1021,7 @@ void iavf_enable_channels(struct iavf_adapter *adapter)
return;
}
- len = struct_size(vti, list, adapter->num_tc - 1);
+ len = struct_size(vti, list, adapter->num_tc);
vti = kzalloc(len, GFP_KERNEL);
if (!vti)
return;
diff --git a/include/linux/avf/virtchnl.h b/include/linux/avf/virtchnl.h
index cda0c98ca978..b554913804bd 100644
--- a/include/linux/avf/virtchnl.h
+++ b/include/linux/avf/virtchnl.h
@@ -529,10 +529,10 @@ VIRTCHNL_CHECK_STRUCT_LEN(16, virtchnl_channel_info);
struct virtchnl_tc_info {
u32 num_tc;
u32 pad;
- struct virtchnl_channel_info list[1];
+ struct virtchnl_channel_info list[];
};
-VIRTCHNL_CHECK_STRUCT_LEN(24, virtchnl_tc_info);
+VIRTCHNL_CHECK_STRUCT_LEN(8, virtchnl_tc_info);
/* VIRTCHNL_ADD_CLOUD_FILTER
* VIRTCHNL_DEL_CLOUD_FILTER
@@ -1106,8 +1106,7 @@ virtchnl_vc_validate_vf_msg(struct virtchnl_version_info *ver, u32 v_opcode,
if (msglen >= valid_len) {
struct virtchnl_tc_info *vti =
(struct virtchnl_tc_info *)msg;
- valid_len += (vti->num_tc - 1) *
- sizeof(struct virtchnl_channel_info);
+ valid_len += flex_array_size(vti, list, vti->num_tc);
if (vti->num_tc == 0)
err_msg_format = true;
}
--
2.27.0