BPF List
 help / color / mirror / Atom feed
From: Oleg Nesterov <oleg@redhat.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Jiri Olsa <olsajiri@gmail.com>,
	yunwei356@gmail.com, Andrii Nakryiko <andrii.nakryiko@gmail.com>,
	bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
	lsf-pc <lsf-pc@lists.linux-foundation.org>,
	Yonghong Song <yonghong.song@linux.dev>,
	Daniel Borkmann <daniel@iogearbox.net>
Subject: Re: [LSF/MM/BPF TOPIC] faster uprobes
Date: Sat, 2 Mar 2024 22:49:32 +0100	[thread overview]
Message-ID: <20240302214932.GA4411@redhat.com> (raw)
In-Reply-To: <CAADnVQKPmJxya14T=BPTK3rfy9sOYMQQ6-oaNHcBtJa5z2nQ=g@mail.gmail.com>

On 03/02, Alexei Starovoitov wrote:
>
> I suspect it's all working fine already.
> Only x86 is using single byte uprobe.
> All other archs are using 2 or 4 byte.

Yes, so we have UPROBE_SWBP_INSN_SIZE

> So replacing an insn or two with a call should work.

Please note that  __uprobe_register(offset) fails if
!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE)

Not to mention that if "call" replaces 2 insns we have another problem:
what if another consumer wants to probe the 2ns insn ?

but perhaps (quite possibly) I misunderstand you.

Oleg.


  reply	other threads:[~2024-03-02 21:51 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-29 14:39 [LSF/MM/BPF TOPIC] faster uprobes Jiri Olsa
2024-03-01  0:25 ` Andrii Nakryiko
2024-03-01  8:18   ` Jiri Olsa
2024-03-01 17:01     ` Alexei Starovoitov
2024-03-01 17:26       ` Andrii Nakryiko
2024-03-01 18:08         ` Yunwei 123
2024-03-03 10:20         ` Jiri Olsa
2024-03-05  0:55           ` Andrii Nakryiko
2024-03-05  8:24             ` Jiri Olsa
2024-03-05 15:30               ` Jiri Olsa
2024-03-05 17:30                 ` Andrii Nakryiko
2024-03-11 10:59               ` Jiri Olsa
2024-03-11 15:06                 ` Oleg Nesterov
2024-03-11 16:46                   ` Jiri Olsa
2024-03-11 17:02                     ` Oleg Nesterov
2024-03-11 21:11                       ` Jiri Olsa
2024-03-11 17:32                 ` Andrii Nakryiko
2024-03-11 21:26                   ` Jiri Olsa
2024-03-11 23:05                     ` Andrii Nakryiko
2024-03-02 20:46       ` Jiri Olsa
2024-03-02 21:08         ` Alexei Starovoitov
2024-03-02 21:49           ` Oleg Nesterov [this message]
2024-03-01 19:39 ` Kui-Feng Lee
2024-03-05 17:18   ` Jiri Olsa
2024-03-05 23:53     ` Song Liu
2024-03-07  9:15       ` Jiri Olsa
2024-03-07 23:02       ` Kui-Feng Lee
2024-03-08 15:43         ` Andrei Matei
2024-03-12 17:16           ` Kui-Feng Lee
2024-03-13  1:32             ` Andrei Matei
2024-03-13  5:42               ` Kui-Feng Lee

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=20240302214932.GA4411@redhat.com \
    --to=oleg@redhat.com \
    --cc=alexei.starovoitov@gmail.com \
    --cc=andrii.nakryiko@gmail.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=lsf-pc@lists.linux-foundation.org \
    --cc=olsajiri@gmail.com \
    --cc=yonghong.song@linux.dev \
    --cc=yunwei356@gmail.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