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From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Edward Cree <ecree@solarflare.com>
Cc: David Ahern <dsahern@gmail.com>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Andrii Nakryiko <andriin@fb.com>, bpf <bpf@vger.kernel.org>,
	Networking <netdev@vger.kernel.org>,
	Alexei Starovoitov <ast@fb.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrey Ignatov <rdna@fb.com>, Kernel Team <kernel-team@fb.com>
Subject: Re: [PATCH v3 bpf-next 0/4] Add support for cgroup bpf_link
Date: Tue, 31 Mar 2020 17:22:31 -0700	[thread overview]
Message-ID: <CAEf4Bza1ueH=SUccfDNScRyURFoQfa1b2z-x1pOfVXuSpGUpmQ@mail.gmail.com> (raw)
In-Reply-To: <869adb74-5192-563d-0e8a-9cb578b2a601@solarflare.com>

On Tue, Mar 31, 2020 at 2:52 PM Edward Cree <ecree@solarflare.com> wrote:
>
> On 31/03/2020 04:54, Andrii Nakryiko wrote:
> > No need to kill random processes, you can kill only those that hold
> > bpf_link FD. You can find them using drgn tool with script like [0].
> For the record, I find the argument "we don't need a query feature,
>  because you can just use a kernel debugger" *utterly* *horrifying*.
> Now, it seems to be moot, because Alexei has given other, better
>  reasons why query doesn't need to land yet; but can we please not
>  ever treat debugging interfaces as a substitute for proper APIs?

Can you please point out where I was objecting to observability API
(which is LINK_QUERY thing we've discussed and I didn't oppose, and
I'm going to add next)?

What I'm doubtful of is this "human override" functionality. I think a
tool that shows who's using (processes and mounted files in BPF FS)
given bpf_link is way more useful, because it allows you to both
"unblock" BPF hook (by killing "bad" processes and removing mounted
bpf_link files) and know which processes (read applications) are
misbehaving.

I'll address drgn vs not concern in reply to David Ahern, who's also
*utterly horrified*, apparently, so I'll try to calm him as well. ;)

>
> </scream>
> -ed

  parent reply	other threads:[~2020-04-01  0:22 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-30  2:59 [PATCH v3 bpf-next 0/4] Add support for cgroup bpf_link Andrii Nakryiko
2020-03-30  2:59 ` [PATCH v3 bpf-next 1/4] bpf: implement bpf_link-based cgroup BPF program attachment Andrii Nakryiko
2020-03-31  0:05   ` Andrey Ignatov
2020-03-31  0:38     ` Alexei Starovoitov
2020-03-31  1:06       ` Andrii Nakryiko
2020-03-30  2:59 ` [PATCH v3 bpf-next 2/4] bpf: implement bpf_prog replacement for an active bpf_cgroup_link Andrii Nakryiko
2020-03-30  3:00 ` [PATCH v3 bpf-next 3/4] libbpf: add support for bpf_link-based cgroup attachment Andrii Nakryiko
2020-03-30  3:00 ` [PATCH v3 bpf-next 4/4] selftests/bpf: test FD-based " Andrii Nakryiko
2020-03-30 14:49 ` [PATCH v3 bpf-next 0/4] Add support for cgroup bpf_link David Ahern
2020-03-30 20:20   ` Andrii Nakryiko
2020-03-30 20:45     ` David Ahern
2020-03-30 20:50       ` Alexei Starovoitov
2020-03-30 22:50       ` Alexei Starovoitov
2020-03-30 23:43         ` David Ahern
2020-03-31  0:32           ` Alexei Starovoitov
2020-03-31  0:57             ` David Ahern
2020-03-31  1:17               ` Alexei Starovoitov
2020-04-01  1:42                 ` David Ahern
2020-04-01  2:04                   ` Alexei Starovoitov
2020-03-31  3:54               ` Andrii Nakryiko
2020-03-31 16:54                 ` David Ahern
2020-03-31 17:03                   ` Andrii Nakryiko
2020-03-31 17:11                   ` Alexei Starovoitov
2020-03-31 21:51                 ` Edward Cree
2020-03-31 22:44                   ` David Ahern
2020-04-01  0:45                     ` Andrii Nakryiko
2020-04-01  0:22                   ` Andrii Nakryiko [this message]
2020-04-01 14:26                     ` Edward Cree
2020-04-01 17:39                       ` Andrii Nakryiko

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