From: Oleg Nesterov <oleg@redhat.com>
To: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Denys Vlasenko <vda.linux@googlemail.com>,
Tejun Heo <tj@kernel.org>, Roland McGrath <roland@redhat.com>,
linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
akpm@linux-foundation.org
Subject: Re: [RFC] Proposal for ptrace improvements
Date: Fri, 4 Mar 2011 18:07:37 +0100 [thread overview]
Message-ID: <20110304170737.GA26904@redhat.com> (raw)
In-Reply-To: <20110304161441.GA12987@host1.jankratochvil.net>
On 03/04, Jan Kratochvil wrote:
>
> On Tue, 01 Mar 2011 23:14:14 +0100, Denys Vlasenko wrote:
> > On Tue, Mar 1, 2011 at 8:06 PM, Jan Kratochvil <jan.kratochvil@redhat.com> wrote:
> > > Currently it is already a problem that apps did not / do not expect the first
> > > waitpid after PTRACE_ATTACH may not be SIGSTOP.
> >
> > That's exactly why we want to add a better alternative, which doesn't
> > insert that blasted SIGSTOP.
>
> But it insteads blasted SIGTRAP (or some other signal) instead.
I don't really understand your concerns... If you modify gdb to use
PTRACE_SEIZE you can forget about the current problems with the first
signal.
Currently gdb has to take care, but mostly because it should "dismiss"
the real signal sent by attach.
> It would be best if such PTRACE_SEIZE (similar to PTRACE_INTERRUPT) would
> guarantee the first waitpid afterwards returns the artificial signal from
> PTRACE_SEIZE.
Again, I don't think this really matters.
Suppose that the tracee reports, say, a signal after PTRACE_SEIZE/INTERRUPT.
And this is possible anyway if the debugger races with kill(). Why this
is bad?
Oleg.
next prev parent reply other threads:[~2011-03-04 17:16 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-01 15:24 [RFC] Proposal for ptrace improvements Tejun Heo
2011-03-01 16:57 ` Denys Vlasenko
2011-03-01 17:09 ` Tejun Heo
2011-03-01 17:12 ` Tejun Heo
2011-03-01 17:21 ` Denys Vlasenko
2011-03-01 18:34 ` Tejun Heo
2011-03-01 23:51 ` Denys Vlasenko
2011-03-02 7:10 ` Tejun Heo
2011-03-02 5:07 ` Indan Zupancic
2011-03-02 7:44 ` Tejun Heo
2011-03-02 11:32 ` Indan Zupancic
2011-03-02 11:52 ` Denys Vlasenko
2011-03-02 14:50 ` Tejun Heo
2011-03-02 13:32 ` Oleg Nesterov
2011-03-03 0:47 ` Indan Zupancic
2011-03-03 1:30 ` Denys Vlasenko
2011-03-03 1:55 ` Indan Zupancic
2011-03-03 7:03 ` Tejun Heo
2011-03-01 19:06 ` Jan Kratochvil
2011-03-01 22:14 ` Denys Vlasenko
2011-03-02 7:28 ` Tejun Heo
2011-03-02 10:58 ` Denys Vlasenko
2011-03-04 16:14 ` Jan Kratochvil
2011-03-04 16:41 ` Denys Vlasenko
2011-03-04 17:07 ` Oleg Nesterov [this message]
2011-03-04 18:12 ` Jan Kratochvil
2011-03-05 8:47 ` Tejun Heo
2011-03-01 22:59 ` Denys Vlasenko
2011-03-02 7:32 ` Tejun Heo
2011-03-02 11:02 ` Denys Vlasenko
2011-03-02 11:23 ` Tejun Heo
2011-03-03 19:26 ` Oleg Nesterov
2011-03-01 23:16 ` Denys Vlasenko
2011-03-02 7:37 ` Tejun Heo
2011-03-02 11:21 ` Denys Vlasenko
2011-03-02 11:27 ` Tejun Heo
2011-03-02 11:48 ` Denys Vlasenko
2011-03-02 14:43 ` Tejun Heo
2011-03-02 15:16 ` Denys Vlasenko
2011-03-02 15:25 ` Tejun Heo
2011-03-03 17:34 ` Oleg Nesterov
2011-03-03 20:22 ` Oleg Nesterov
2011-03-04 8:23 ` Tejun Heo
2011-03-04 18:16 ` Oleg Nesterov
2011-03-05 8:33 ` Tejun Heo
2011-03-04 13:01 ` Denys Vlasenko
2011-03-04 13:41 ` Tejun Heo
2011-03-04 13:59 ` Denys Vlasenko
2011-03-04 14:07 ` Tejun Heo
2011-03-04 14:31 ` Denys Vlasenko
2011-03-04 14:40 ` Tejun Heo
2011-03-04 17:05 ` Denys Vlasenko
2011-03-04 17:12 ` Linus Torvalds
2011-03-04 18:59 ` Denys Vlasenko
2011-03-04 19:24 ` Linus Torvalds
2011-03-04 16:13 ` Oleg Nesterov
2011-03-04 16:30 ` Oleg Nesterov
2011-03-04 8:44 ` Tejun Heo
2011-03-04 16:01 ` Oleg Nesterov
2011-03-04 16:15 ` Tejun Heo
2011-03-04 16:26 ` Oleg Nesterov
2011-03-07 15:08 ` PTRACE_SEIZE/INTERRUPT: " Oleg Nesterov
2011-03-09 9:41 ` Tejun Heo
2011-03-09 17:30 ` Oleg Nesterov
2011-03-07 20:43 ` Roland McGrath
2011-03-09 10:28 ` Tejun Heo
2011-03-10 18:33 ` Steven Rostedt
2011-03-11 8:13 ` Tejun Heo
2011-03-11 8:22 ` Ingo Molnar
2011-03-11 9:35 ` Srikar Dronamraju
2011-03-11 9:43 ` Ingo Molnar
2011-03-14 1:03 ` Frank Ch. Eigler
2011-03-10 15:55 ` Steven Rostedt
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=20110304170737.GA26904@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=jan.kratochvil@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=roland@redhat.com \
--cc=tj@kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=vda.linux@googlemail.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 NNTP newsgroup(s).