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From: Yafang Shao <laoar.shao@gmail.com>
To: "Toke Høiland-Jørgensen" <toke@kernel.org>
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
	haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH bpf-next 08/13] bpf: Alloc and free bpf_map id in bpf namespace
Date: Mon, 27 Mar 2023 10:44:12 +0800	[thread overview]
Message-ID: <CALOAHbBd5Bx0Tnzv1MW_NV9mOJrqdk5oySYWQr-XXURAM5xndw@mail.gmail.com> (raw)
In-Reply-To: <87mt3z7pm5.fsf@toke.dk>

On Sun, Mar 26, 2023 at 6:51 PM Toke Høiland-Jørgensen <toke@kernel.org> wrote:
>
> Yafang Shao <laoar.shao@gmail.com> writes:
>
> > We only expose the bpf map id under current bpf namespace to user. The
> > map->id is still the id in the init bpf namespace.
> >
> > The result as follows,
> >
> > Run bpftool in a new bpf namespace
> > $ bpftool map show
> > 4: array  name kprobe_b.rodata  flags 0x80
> >         key 4B  value 37B  max_entries 1  memlock 360B
> >         btf_id 159  frozen
>
> The btf_id is identical for all the different objects in this example
> output; surely that can't be right? Copy-paste error? Same thing in the
> other patches...
>

The bpf progs {"kretprobe_run","kprobe_run"} and the bpf maps
{"kprobe_b.rodata","kprobe_b.data"} belong to the same bpf program. So
the btf_id of them are always the same. For example, below is the
result when I rerun it on my test server,
$ bpftool btf show
...
943: name <anon>  size 1086B  prog_ids 48824,48822  map_ids 43712,43711
        pids kprobe(3599801)
...

$ bpftool map show
43711: array  name kprobe_b.rodata  flags 0x80
        key 4B  value 37B  max_entries 1  memlock 360B
        btf_id 943  frozen
        pids kprobe(3599801)
43712: array  name kprobe_b.data  flags 0x400
        key 4B  value 4B  max_entries 1  memlock 8192B
        btf_id 943
        pids kprobe(3599801)

$ bpftool prog show
48822: kprobe  name kretprobe_run  tag 0de47cc241a2b1b3  gpl
        loaded_at 2023-03-27T10:35:01+0800  uid 0
        xlated 112B  jited 78B  memlock 4096B  map_ids 43711
        btf_id 943
        pids kprobe(3599801)
48824: kprobe  name kprobe_run  tag bf163b23cd3b174d  gpl
        loaded_at 2023-03-27T10:35:01+0800  uid 0
        xlated 104B  jited 75B  memlock 4096B  map_ids 43711
        btf_id 943
        pids kprobe(3599801)

The btf_id hasn't been added into the bpf namespace, so the btf id in
init bpf namespace and child bpf namespace are the same value.

-- 
Regards
Yafang

  reply	other threads:[~2023-03-27  2:44 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-26  9:21 [RFC PATCH bpf-next 00/13] bpf: Introduce BPF namespace Yafang Shao
2023-03-26  9:21 ` [RFC PATCH bpf-next 01/13] fork: New clone3 flag for " Yafang Shao
2023-03-26  9:21 ` [RFC PATCH bpf-next 02/13] proc_ns: Extend the field type in struct proc_ns_operations to long Yafang Shao
2023-03-26  9:21 ` [RFC PATCH bpf-next 03/13] bpf: Implement bpf namespace Yafang Shao
2023-03-26  9:21 ` [RFC PATCH bpf-next 04/13] bpf: No need to check if id is 0 Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 05/13] bpf: Make bpf objects id have the same alloc and free pattern Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 06/13] bpf: Helpers to alloc and free object id in bpf namespace Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 07/13] bpf: Add bpf helper to get bpf object id Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 08/13] bpf: Alloc and free bpf_map id in bpf namespace Yafang Shao
2023-03-26 10:50   ` Toke Høiland-Jørgensen
2023-03-27  2:44     ` Yafang Shao [this message]
2023-03-26  9:22 ` [RFC PATCH bpf-next 09/13] bpf: Alloc and free bpf_prog " Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 10/13] bpf: Alloc and free bpf_link " Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 11/13] bpf: Allow iterating bpf objects with CAP_BPF " Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 12/13] bpf: Use bpf_idr_lock array instead Yafang Shao
2023-03-26  9:22 ` [RFC PATCH bpf-next 13/13] selftests/bpf: Add selftest for bpf namespace Yafang Shao
2023-03-26 10:49 ` [RFC PATCH bpf-next 00/13] bpf: Introduce BPF namespace Toke Høiland-Jørgensen
2023-03-27  3:07   ` Yafang Shao
2023-03-27 20:51     ` Toke Høiland-Jørgensen
2023-03-28  3:48       ` Yafang Shao
2023-03-27 17:28 ` Stanislav Fomichev
2023-03-28  3:42   ` Yafang Shao
2023-03-28 17:15     ` Stanislav Fomichev
2023-03-29  3:02       ` Yafang Shao
2023-03-29 20:50         ` Stanislav Fomichev
2023-03-30  2:40           ` Yafang Shao
2023-03-27 19:03 ` Song Liu
2023-03-28  3:47   ` Yafang Shao
2023-04-02 23:37     ` Alexei Starovoitov
2023-04-03  3:05       ` Yafang Shao
2023-04-03 22:50         ` Alexei Starovoitov
2023-04-04  2:59           ` Yafang Shao
2023-04-06  2:06             ` Alexei Starovoitov
2023-04-06  2:54               ` Yafang Shao
2023-04-06  3:05                 ` Alexei Starovoitov
2023-04-06  3:22                   ` Yafang Shao
2023-04-06  4:24                     ` Alexei Starovoitov
2023-04-06  5:43                       ` Yafang Shao
2023-04-06 20:22                         ` Andrii Nakryiko
2023-04-07  1:43                           ` Alexei Starovoitov
2023-04-07  4:33                             ` Yafang Shao
2023-04-07 15:32                               ` Alexei Starovoitov
2023-04-07 15:59                             ` Andrii Nakryiko
2023-04-07 16:05                               ` Alexei Starovoitov
2023-04-07 16:21                                 ` Yafang Shao
2023-04-07 16:31                                   ` Alexei Starovoitov
2023-04-07 16:35                                     ` Yafang Shao
2023-03-31  5:52 ` Hao Luo
2023-04-01 16:32   ` Yafang Shao

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