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: Sun, 25 Jun 2023 03:18:58 +0200 [thread overview]
Message-ID: <ZJeWAiW5qxQPghGm@krava> (raw)
In-Reply-To: <CAEf4BzaQGqhO3hoGW-zvhioE=VKVpuMw5NTTvUw=sXTEoFptxA@mail.gmail.com>
On Fri, Jun 23, 2023 at 09:24:22AM -0700, Andrii Nakryiko wrote:
SNIP
> > > > +
> > > > + if (!uprobes || !ref_ctr_offsets || !link)
> > > > + goto error_free;
> > > > +
> > > > + for (i = 0; i < cnt; i++) {
> > > > + if (uref_ctr_offsets && __get_user(ref_ctr_offset, uref_ctr_offsets + i)) {
> > > > + err = -EFAULT;
> > > > + goto error_free;
> > > > + }
> > > > + if (__get_user(offset, uoffsets + i)) {
> > > > + err = -EFAULT;
> > > > + goto error_free;
> > > > + }
> > > > +
> > > > + uprobes[i].offset = offset;
> > > > + uprobes[i].link = link;
> > > > +
> > > > + if (flags & BPF_F_UPROBE_MULTI_RETURN)
> > > > + uprobes[i].consumer.ret_handler = uprobe_multi_link_ret_handler;
> > > > + else
> > > > + uprobes[i].consumer.handler = uprobe_multi_link_handler;
> > > > +
> > > > + ref_ctr_offsets[i] = ref_ctr_offset;
> > > > + }
> > > > +
> > > > + link->cnt = cnt;
> > > > + link->uprobes = uprobes;
> > > > + link->path = path;
> > > > +
> > > > + bpf_link_init(&link->link, BPF_LINK_TYPE_UPROBE_MULTI,
> > > > + &bpf_uprobe_multi_link_lops, prog);
> > > > +
> > > > + err = bpf_link_prime(&link->link, &link_primer);
> > > > + if (err)
> > > > + goto error_free;
> > > > +
> > > > + for (i = 0; i < cnt; i++) {
> > > > + err = uprobe_register_refctr(d_real_inode(link->path.dentry),
> > > > + uprobes[i].offset, ref_ctr_offsets[i],
> > > > + &uprobes[i].consumer);
> > > > + if (err) {
> > > > + bpf_uprobe_unregister(&path, uprobes, i);
> > >
> > > 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
jirka
>
> >
> > I think I can add simple selftest to have this path covered
> >
> > thanks,
> > jirka
SNIP
next prev parent reply other threads:[~2023-06-25 1:19 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 [this message]
2023-06-26 18:27 ` Andrii Nakryiko
2023-06-26 19:23 ` Jiri Olsa
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZJeWAiW5qxQPghGm@krava \
--to=olsajiri@gmail.com \
--cc=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=haoluo@google.com \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kpsingh@chromium.org \
--cc=sdf@google.com \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox