From: Jesper Dangaard Brouer <brouer@redhat•com>
To: Daniel Borkmann <daniel@iogearbox•net>
Cc: davem@davemloft•net, ast@fb•com, john.fastabend@gmail•com,
andy@greyhouse•net, netdev@vger•kernel.org, brouer@redhat•com
Subject: Re: [PATCH net] bpf: don't select potentially stale ri->map from buggy xdp progs
Date: Fri, 8 Sep 2017 07:06:10 +0200 [thread overview]
Message-ID: <20170908070610.4b8e1df1@redhat.com> (raw)
In-Reply-To: <01d69254802986ad3a8b18a8650c45df3df95def.1504821825.git.daniel@iogearbox.net>
On Fri, 8 Sep 2017 00:14:51 +0200
Daniel Borkmann <daniel@iogearbox•net> wrote:
> + /* This is really only caused by a deliberately crappy
> + * BPF program, normally we would never hit that case,
> + * so no need to inform someone via tracepoints either,
> + * just bail out.
> + */
> + if (unlikely(map_owner != xdp_prog))
> + return -EINVAL;
IMHO we do need to call the tracepoint here. It is not just crappy
BPF-progs that cause this situation, it is also drivers not implementing
XDP_REDIRECT yet (which is all but ixgbe). Due to the level XDP
operates at, tracepoints are the only way users can runtime troubleshoot
their XDP programs.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2017-09-08 5:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-07 22:14 [PATCH net] bpf: don't select potentially stale ri->map from buggy xdp progs Daniel Borkmann
2017-09-07 22:37 ` Alexei Starovoitov
2017-09-08 5:06 ` Jesper Dangaard Brouer [this message]
2017-09-08 10:34 ` Daniel Borkmann
2017-09-08 11:52 ` Jesper Dangaard Brouer
2017-09-08 12:34 ` Daniel Borkmann
2017-09-08 13:07 ` Jesper Dangaard Brouer
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