From: "Toke Høiland-Jørgensen" <toke@toke.dk>
To: Saeed Mahameed <saeedm@mellanox.com>,
"netdev\@vger.kernel.org" <netdev@vger.kernel.org>
Cc: Eran Ben Elisha <eranbe@mellanox.com>,
Tariq Toukan <tariqt@mellanox.com>,
"brouer\@redhat.com" <brouer@redhat.com>
Subject: Re: Kernel oops with mlx5 and dual XDP redirect programs
Date: Thu, 04 Oct 2018 14:03:34 +0200 [thread overview]
Message-ID: <87efd5dill.fsf@toke.dk> (raw)
In-Reply-To: <4e2cfdc3db244f4b9483a0c3dfc62fae55238bb3.camel@mellanox.com>
Saeed Mahameed <saeedm@mellanox.com> writes:
> On Wed, 2018-10-03 at 11:30 +0200, Toke Høiland-Jørgensen wrote:
>> Hi Saeed
>>
>> I can reliably oops the kernel with the mlx5 driver, by installing
>> XDP_REDIRECT programs on two devices so they redirect to each other,
>> and then remove them while there is traffic on the interface.
>>
>> Steps to reproduce:
>>
>> # cd ~/build/linux/samples/bpf
>> # ./xdp_redirect_map $(</sys/class/net/ens1f1/ifindex)
>> $(</sys/class/net/ens1f0/ifindex)
>> # ./xdp_redirect_map $(</sys/class/net/ens1f0/ifindex)
>> $(</sys/class/net/ens1f1/ifindex)
>>
>> Now, run some traffic (e.g., using pktgen) across the interfaces, and
>> while the traffic is running, interrupt one of the xdp_redirect_map
>> commands (thus unloading the eBPF program). This results in a kernel
>> oops with the backtrace below. I get no crash if there's only a
>> single
>> XDP program.
>
> Hi Toke,
>
> What looks like happening is that while the traffic is being redirected
> to the other device, the driver is trying to unload the program and
> restarting the rings from below call trace we can see:
Yeah, thought it was something like that, since it only happens on the
bidirectional redirect...
> I think that the mlx5 driver doesn't know how to tell the other device
> to stop transmitting to it while it is resetting.. Maybe tariq or
> Jesper know more about this ?
> I will look at this tomorrow after noon and will try to repro...
Great, thanks! :)
-Toke
next prev parent reply other threads:[~2018-10-04 18:56 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-03 9:30 Kernel oops with mlx5 and dual XDP redirect programs Toke Høiland-Jørgensen
2018-10-03 23:44 ` Saeed Mahameed
2018-10-04 12:03 ` Toke Høiland-Jørgensen [this message]
2018-10-18 21:53 ` Toke Høiland-Jørgensen
2018-10-22 17:57 ` Saeed Mahameed
2018-10-23 10:10 ` Toke Høiland-Jørgensen
2018-10-23 18:01 ` Saeed Mahameed
2018-10-23 20:29 ` Toke Høiland-Jørgensen
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