From: "Toke Høiland-Jørgensen" <toke@redhat•com>
To: Arnaldo Carvalho de Melo <acme@kernel•org>,
Andrii Nakryiko <andrii.nakryiko@gmail•com>
Cc: 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>,
Kernel Team <kernel-team@fb•com>, Hao Luo <haoluo@google•com>,
Song Liu <songliubraving@fb•com>,
Quentin Monnet <quentin@isovalent•com>
Subject: Re: [RFC PATCH bpf-next 8/8] tools/bpftool: show PIDs with FDs open against BPF map/prog/link/btf
Date: Mon, 15 Jun 2020 11:04:34 +0200 [thread overview]
Message-ID: <87pna01yzh.fsf@toke.dk> (raw)
In-Reply-To: <20200613221419.GB7488@kernel.org>
Arnaldo Carvalho de Melo <acme@kernel•org> writes:
> Em Fri, Jun 12, 2020 at 10:57:59PM -0700, Andrii Nakryiko escreveu:
>> On Fri, Jun 12, 2020 at 8:45 PM Alexei Starovoitov
>> <alexei.starovoitov@gmail•com> wrote:
>> >
>> > On Fri, Jun 12, 2020 at 03:31:50PM -0700, Andrii Nakryiko wrote:
>> > > Add bpf_iter-based way to find all the processes that hold open FDs against
>> > > BPF object (map, prog, link, btf). Add new flag (-o, for "ownership", given
>> > > -p is already taken) to trigger collection and output of these PIDs.
>> > >
>> > > Sample output for each of 4 BPF objects:
>> > >
>> > > $ sudo ./bpftool -o prog show
>> > > 1992: cgroup_skb name egress_alt tag 9ad187367cf2b9e8 gpl
>> > > loaded_at 2020-06-12T14:18:10-0700 uid 0
>> > > xlated 48B jited 59B memlock 4096B map_ids 2074
>> > > btf_id 460
>> > > pids: 913709,913732,913733,913734
>> > > 2062: cgroup_device tag 8c42dee26e8cd4c2 gpl
>> > > loaded_at 2020-06-12T14:37:52-0700 uid 0
>> > > xlated 648B jited 409B memlock 4096B
>> > > pids: 1
>> > >
>> > > $ sudo ./bpftool -o map show
>> > > 2074: array name test_cgr.bss flags 0x400
>> > > key 4B value 8B max_entries 1 memlock 8192B
>> > > btf_id 460
>> > > pids: 913709,913732,913733,913734
>> > >
>> > > $ sudo ./bpftool -o link show
>> > > 82: cgroup prog 1992
>> > > cgroup_id 0 attach_type egress
>> > > pids: 913709,913732,913733,913734
>> > > 86: cgroup prog 1992
>> > > cgroup_id 0 attach_type egress
>> > > pids: 913709,913732,913733,913734
>> >
>> > This is awesome.
>
> Indeed.
>
>> Thanks.
>>
>> >
>> > Why extra flag though? I think it's so useful that everyone would want to see
>
> Agreed.
>
>> No good reason apart from "being safe by default". If turned on by
>> default, bpftool would need to probe for bpf_iter support first. I can
>> add probing and do this by default.
>
> I think this is the way to go.
+1
And also +1 on the awesomeness of this feature! :)
-Toke
next prev parent reply other threads:[~2020-06-15 9:04 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200612223150.1177182-1-andriin@fb.com>
[not found] ` <20200612223150.1177182-9-andriin@fb.com>
2020-06-13 3:45 ` [RFC PATCH bpf-next 8/8] tools/bpftool: show PIDs with FDs open against BPF map/prog/link/btf Alexei Starovoitov
2020-06-13 5:57 ` Andrii Nakryiko
2020-06-13 22:14 ` Arnaldo Carvalho de Melo
2020-06-15 9:04 ` Toke Høiland-Jørgensen [this message]
2020-06-15 9:30 ` Quentin Monnet
[not found] ` <20200612223150.1177182-2-andriin@fb.com>
[not found] ` <CA+khW7hAYVdoQX5-j0z1iGEVZeww4BBu4NXzy5eS5OwDRYqe2w@mail.gmail.com>
2020-06-15 18:55 ` [RFC PATCH bpf-next 1/8] libbpf: generalize libbpf externs support Andrii Nakryiko
[not found] ` <20200612223150.1177182-3-andriin@fb.com>
[not found] ` <CA+khW7hFZzp_K_xydSFw0O3LYB22_fC=Z4wG7i9Si+phGHn4cQ@mail.gmail.com>
2020-06-15 19:08 ` [RFC PATCH bpf-next 2/8] libbpf: add support for extracting kernel symbol addresses Andrii Nakryiko
2020-06-16 8:05 ` Hao Luo
2020-06-17 1:24 ` Hao Luo
2020-06-17 1:36 ` Andrii Nakryiko
2020-06-18 7:53 ` Hao Luo
[not found] ` <20200612223150.1177182-4-andriin@fb.com>
[not found] ` <CA+khW7jxdS1KRpk2syVGjDqbyn3wAd3Eh_LEMAEhkPUehuXMwg@mail.gmail.com>
2020-06-15 19:11 ` [RFC PATCH bpf-next 3/8] selftests/bpf: add __ksym extern selftest Andrii Nakryiko
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