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From: Daniel Borkmann <daniel@iogearbox.net>
To: David Ahern <dsa@cumulusnetworks.com>,
	netdev@vger.kernel.org, alexei.starovoitov@gmail.com
Cc: roopa@cumulusnetworks.com
Subject: Re: [RFC PATCH net-next 1/2] bpf: Save original ebpf instructions
Date: Fri, 03 Feb 2017 22:09:46 +0100	[thread overview]
Message-ID: <5894F19A.60305@iogearbox.net> (raw)
In-Reply-To: <1486154303-32278-2-git-send-email-dsa@cumulusnetworks.com>

On 02/03/2017 09:38 PM, David Ahern wrote:
> Similar to classic bpf, support saving original ebpf instructions
>
> Signed-off-by: David Ahern <dsa@cumulusnetworks.com>

Not convinced that this is in the right direction, this not only *significantly*
increases mem footprint for each and every program, but also when you dump this,
then map references from relocs inside the insns are meaningless (f.e. what about
prog arrays used in tail calls?), so things like criu also won't be able to use
this kind of interface for dump and restore. If it's just for debugging, then
why not extend the existing tracing infrastructure around bpf that was started
with intention to gain more visibility.

Thanks,
Daniel

  reply	other threads:[~2017-02-03 21:09 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-03 20:38 [RFC PATCH net-next 0/2] bpf: Allow retrieval of ebpf filters David Ahern
2017-02-03 20:38 ` [RFC PATCH net-next 1/2] bpf: Save original ebpf instructions David Ahern
2017-02-03 21:09   ` Daniel Borkmann [this message]
2017-02-03 22:28     ` David Ahern
2017-02-06 10:56       ` Quentin Monnet
2017-02-06 14:13         ` Daniel Borkmann
2017-02-06 19:21           ` Alexei Starovoitov
2017-02-07 17:22             ` David Ahern
2017-02-08 10:52               ` Daniel Borkmann
2017-02-08 19:40                 ` David Ahern
2017-02-09  1:28                   ` David Ahern
2017-02-09 11:25                   ` Daniel Borkmann
2017-02-10  5:22                     ` Alexei Starovoitov
2017-02-10 22:45                       ` Daniel Borkmann
2017-02-03 20:38 ` [RFC PATCH net-next 2/2] bpf: Add support to retrieve program attached to a cgroup David Ahern

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