From: Jiri Olsa <olsajiri@gmail.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Jiri Olsa <olsajiri@gmail.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
bpf@vger.kernel.org, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>
Subject: Re: [PATCHv2 bpf-next 01/24] bpf: Add multi uprobe link
Date: Mon, 26 Jun 2023 21:23:20 +0200 [thread overview]
Message-ID: <ZJnlqOlGhztFCyah@krava> (raw)
In-Reply-To: <CAEf4BzYq6DJhWbVFnb2W_qWNDjObAHcd6agRdmp=OsP23A7O7w@mail.gmail.com>
On Mon, Jun 26, 2023 at 11:27:25AM -0700, Andrii Nakryiko wrote:
SNIP
> > > > > bpf_link_cleanup() will do this through
> > > > > bpf_uprobe_multi_link_release(), no? So you are double unregistering?
> > > > > Either drop cnt to zero, or just don't do this here? Latter is better,
> > > > > IMO.
> > > >
> > > > bpf_link_cleanup path won't call release callback so we have to do that
> > >
> > > bpf_link_cleanup() does fput(primer->file); which eventually calls
> > > release callback, no? I'd add printk and simulate failure just to be
> > > sure
> >
> > I recall we had similar discussion for kprobe_multi link ;-)
> >
> > I'll double check that but I think bpf_link_cleanup calls just
> > dealloc callback not release
>
> Let's document this in comments for bpf_link_cleanup() so we don't
> have to discuss this again :)
>
> I think you are right, btw. I see that bpf_link_cleanup() sets
> link->prog to NULL, and bpf_link_free() won't call
> link->ops->release() if link->prog is NULL.
>
> Tricky, I keep forgetting this. Let's explicitly explain this in a comment.
ok, will add the comment
jirka
>
> >
> > jirka
> >
> > >
> > > >
> > > > I think I can add simple selftest to have this path covered
> > > >
> > > > thanks,
> > > > jirka
> >
> > SNIP
next prev parent reply other threads:[~2023-06-26 19:23 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-20 8:35 [PATCHv2 bpf-next 00/24] bpf: Add multi uprobe link Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 01/24] " Jiri Olsa
2023-06-20 17:11 ` Alexei Starovoitov
2023-06-21 8:32 ` Jiri Olsa
2023-06-23 0:18 ` Andrii Nakryiko
2023-06-23 8:19 ` Jiri Olsa
2023-06-23 16:24 ` Andrii Nakryiko
2023-06-23 16:39 ` Alexei Starovoitov
2023-06-23 17:11 ` Andrii Nakryiko
2023-06-23 17:20 ` Alexei Starovoitov
2023-06-25 1:19 ` Jiri Olsa
2023-06-25 1:18 ` Jiri Olsa
2023-06-26 18:27 ` Andrii Nakryiko
2023-06-26 19:23 ` Jiri Olsa [this message]
2023-06-20 8:35 ` [PATCHv2 bpf-next 02/24] bpf: Add cookies support for uprobe_multi link Jiri Olsa
2023-06-23 0:18 ` Andrii Nakryiko
2023-06-23 8:01 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 03/24] bpf: Add pid filter " Jiri Olsa
2023-06-20 12:40 ` Oleg Nesterov
2023-06-20 8:35 ` [PATCHv2 bpf-next 04/24] bpf: Add bpf_get_func_ip helper support for uprobe link Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 05/24] libbpf: Add uprobe_multi attach type and link names Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 06/24] libbpf: Add elf symbol iterator Jiri Olsa
2023-06-23 0:31 ` Andrii Nakryiko
2023-06-23 8:19 ` Jiri Olsa
2023-06-23 16:27 ` Andrii Nakryiko
2023-06-23 16:29 ` Andrii Nakryiko
2023-06-20 8:35 ` [PATCHv2 bpf-next 07/24] libbpf: Add open_elf/close_elf functions Jiri Olsa
2023-06-23 0:33 ` Andrii Nakryiko
2023-06-23 8:21 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 08/24] libbpf: Add elf_find_multi_func_offset function Jiri Olsa
2023-06-23 20:39 ` Andrii Nakryiko
2023-06-25 1:19 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 09/24] libbpf: Add elf_find_pattern_func_offset function Jiri Olsa
2023-06-23 20:39 ` Andrii Nakryiko
2023-06-25 1:19 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 10/24] libbpf: Add bpf_link_create support for multi uprobes Jiri Olsa
2023-06-23 20:40 ` Andrii Nakryiko
2023-06-20 8:35 ` [PATCHv2 bpf-next 11/24] libbpf: Add bpf_program__attach_uprobe_multi_opts function Jiri Olsa
2023-06-23 20:40 ` Andrii Nakryiko
2023-06-25 1:19 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 12/24] libbpf: Add support for u[ret]probe.multi[.s] program sections Jiri Olsa
2023-06-23 20:40 ` Andrii Nakryiko
2023-06-25 1:20 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 13/24] libbpf: Add uprobe multi link detection Jiri Olsa
2023-06-23 20:40 ` Andrii Nakryiko
2023-06-25 1:18 ` Jiri Olsa
2023-06-26 18:21 ` Andrii Nakryiko
2023-06-26 19:22 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 14/24] libbpf: Add uprobe multi link support to bpf_program__attach_usdt Jiri Olsa
2023-06-23 20:40 ` Andrii Nakryiko
2023-06-25 1:18 ` Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 15/24] selftests/bpf: Add uprobe_multi skel test Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 16/24] selftests/bpf: Add uprobe_multi api test Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 17/24] selftests/bpf: Add uprobe_multi link test Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 18/24] selftests/bpf: Add uprobe_multi test program Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 19/24] selftests/bpf: Add uprobe_multi bench test Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 20/24] selftests/bpf: Add usdt_multi test program Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 21/24] selftests/bpf: Add usdt_multi bench test Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 22/24] selftests/bpf: Add uprobe_multi cookie test Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 23/24] selftests/bpf: Add uprobe_multi pid filter tests Jiri Olsa
2023-06-20 8:35 ` [PATCHv2 bpf-next 24/24] selftests/bpf: Add extra link to uprobe_multi tests Jiri Olsa
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