From: Jiri Olsa <olsajiri@gmail.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Jiri Olsa <olsajiri@gmail.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
bpf@vger.kernel.org, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Borislav Petkov (AMD)" <bp@alien8.de>,
x86@kernel.org, linux-api@vger.kernel.org
Subject: Re: [PATCHv2 1/3] uprobe: Add uretprobe syscall to speed up return probe
Date: Tue, 9 Apr 2024 14:06:19 +0200 [thread overview]
Message-ID: <ZhUvO4lHn-xh3jDm@krava> (raw)
In-Reply-To: <20240408162258.GC25058@redhat.com>
On Mon, Apr 08, 2024 at 06:22:59PM +0200, Oleg Nesterov wrote:
> On 04/08, Jiri Olsa wrote:
> >
> > On Fri, Apr 05, 2024 at 01:02:30PM +0200, Oleg Nesterov wrote:
> > >
> > > And what should sys_uretprobe() do if it is not called from the trampoline?
> > > I'd prefer force_sig(SIGILL) to punish the abuser ;) OK, OK, EINVAL.
> >
> > so the similar behaviour with int3 ends up with immediate SIGTRAP
> > and not invoking pending uretprobe consumers, like:
> >
> > - setup uretprobe for foo
> > - foo() {
> > executes int 3 -> sends SIGTRAP
> > }
> >
> > because the int3 handler checks if it got executed from the uretprobe's
> > trampoline.
>
> ... or the task has uprobe at this address
>
> > if not it treats that int3 as regular trap
>
> Yes this mimics the "default" behaviour without uprobes/uretprobes
>
> > so I think we should mimic int3 behaviour and:
> >
> > - setup uretprobe for foo
> > - foo() {
> > uretprobe_syscall -> check if we got executed from uretprobe's
> > trampoline and send SIGILL if that's not the case
>
> Agreed,
>
> > I think it's better to have the offending process killed right away,
> > rather than having more undefined behaviour, waiting for final 'ret'
> > instruction that jumps to uretprobe trampoline and causes SIGILL
>
> Agreed. In fact I think it should be also killed if copy_to/from_user()
> fails by the same reason.
+1 makes sense
jirka
>
> Oleg.
>
next prev parent reply other threads:[~2024-04-09 12:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240402093302.2416467-1-jolsa@kernel.org>
[not found] ` <20240402093302.2416467-2-jolsa@kernel.org>
[not found] ` <20240403100708.233575a8ac2a5bac2192d180@kernel.org>
[not found] ` <Zg0lvUIB4WdRUGw_@krava>
[not found] ` <20240403230937.c3bd47ee47c102cd89713ee8@kernel.org>
[not found] ` <CAEf4BzZ2RFfz8PNgJ4ENZ0us4uX=DWhYFimXdtWms-VvGXOjgQ@mail.gmail.com>
[not found] ` <20240404095829.ec5db177f29cd29e849169fa@kernel.org>
[not found] ` <CAEf4BzYH60TwvBipHWB_kUqZZ6D-iUVnnFsBv06imRikK3o-bg@mail.gmail.com>
2024-04-04 15:54 ` [PATCHv2 1/3] uprobe: Add uretprobe syscall to speed up return probe Masami Hiramatsu
2024-04-04 16:11 ` Oleg Nesterov
2024-04-05 1:22 ` Masami Hiramatsu
2024-04-05 8:56 ` Jiri Olsa
2024-04-05 11:02 ` Oleg Nesterov
2024-04-06 3:05 ` Masami Hiramatsu
2024-04-06 17:55 ` Oleg Nesterov
2024-04-08 3:54 ` Masami Hiramatsu
2024-04-08 16:02 ` Jiri Olsa
2024-04-08 16:22 ` Oleg Nesterov
2024-04-09 12:06 ` Jiri Olsa [this message]
2024-04-09 0:34 ` Masami Hiramatsu
2024-04-09 7:57 ` Jiri Olsa
2024-04-08 3:16 ` Masami Hiramatsu
[not found] ` <Zg6V8y2-OP_9at2l@krava>
2024-04-04 16:06 ` Masami Hiramatsu
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=ZhUvO4lHn-xh3jDm@krava \
--to=olsajiri@gmail.com \
--cc=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bp@alien8.de \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=songliubraving@fb.com \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).