Re: [PATCH v4 net-next] vmxnet3: Remove buf_info from device accessible structures

[Jakub Kicinski]

On Tue, 26 Jan 2021 11:06:40 -0800 Ronak Doshi wrote:
> buf_info structures in RX & TX queues are private driver data that
> do not need to be visible to the device.  Although there is physical
> address and length in the queue descriptor that points to these
> structures, their layout is not standardized, and device never looks
> at them.
> 
> So lets allocate these structures in non-DMA-able memory, and fill
> physical address as all-ones and length as zero in the queue
> descriptor.
> 
> That should alleviate worries brought by Martin Radev in
> https://lists.osuosl.org/pipermail/intel-wired-lan/Week-of-Mon-20210104/022829.html
> that malicious vmxnet3 device could subvert SVM/TDX guarantees.
> 
> Signed-off-by: Petr Vandrovec <petr@xxxxxxxxxx>
> Signed-off-by: Ronak Doshi <doshir@xxxxxxxxxx>

Checkpatch says:

WARNING: kfree(NULL) is safe and this check is probably not required
#39: FILE: drivers/net/vmxnet3/vmxnet3_drv.c:455:
 	if (tq->buf_info) {
+		kfree(tq->buf_info);

WARNING: kfree(NULL) is safe and this check is probably not required
#73: FILE: drivers/net/vmxnet3/vmxnet3_drv.c:1737:
 	if (rq->buf_info[0]) {
+		kfree(rq->buf_info[0]);


You can remove those ifs as well.