Subject: Re: [PATCH net v2] i40e: fix the panic when running bpf in xdpdrv mode

From: Jesse Brandeburg <[email-masked]>
Date: Tue, 13 Apr 2021 09:18:12 -0700

[email-masked] wrote:

> From: Jason Xing <[email-masked]>

Hi Jason,

Sorry, I missed this on the first time: Added intel-wired-lan,
please include on any future submissions for Intel drivers.
get-maintainers script might help here?

> 
> Fix this panic by adding more rules to calculate the value of @rss_size_max
> which could be used in allocating the queues when bpf is loaded, which,
> however, could cause the failure and then trigger the NULL pointer of
> vsi->rx_rings. Prio to this fix, the machine doesn't care about how many
> cpus are online and then allocates 256 queues on the machine with 32 cpus
> online actually.
> 
> Once the load of bpf begins, the log will go like this "failed to get
> tracking for 256 queues for VSI 0 err -12" and this "setup of MAIN VSI
> failed".
> 
> Thus, I attach the key information of the crash-log here.
> 
> BUG: unable to handle kernel NULL pointer dereference at
> 0000000000000000
> RIP: 0010:i40e_xdp+0xdd/0x1b0 [i40e]
> Call Trace:
> [2160294.717292]  ? i40e_reconfig_rss_queues+0x170/0x170 [i40e]
> [2160294.717666]  dev_xdp_install+0x4f/0x70
> [2160294.718036]  dev_change_xdp_fd+0x11f/0x230
> [2160294.718380]  ? dev_disable_lro+0xe0/0xe0
> [2160294.718705]  do_setlink+0xac7/0xe70
> [2160294.719035]  ? __nla_parse+0xed/0x120
> [2160294.719365]  rtnl_newlink+0x73b/0x860
> 
> Fixes: 41c445ff0f48 ("i40e: main driver core")
> 

This Fixes line should be connected to the Sign offs with
no linefeeds between.

> Signed-off-by: Jason Xing <[email-masked]>
> Signed-off-by: Shujin Li <[email-masked]>

Did Shujin contribute to this patch? Why are they signing off? If
they developed this patch with you, it should say:
Co-developed-by: Shujin ....
Signed-off-by: Shujin ...
Signed-off-by: Jason ...

Your signature should be last if you sent the patch. The sign-offs are
like a chain of custody, please review 
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#when-to-use-acked-by-cc-and-co-developed-by

Thanks,
 Jesse