From: Tejun Heo <tj@kernel.org>
To: Pedro Alves <pedro@codesourcery.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
Denys Vlasenko <vda.linux@googlemail.com>,
jan.kratochvil@redhat.com, linux-kernel@vger.kernel.org,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
indan@nul.nu, bdonlan@gmail.com
Subject: Re: [PATCH 03/10] ptrace: implement PTRACE_SEIZE
Date: Thu, 26 May 2011 12:11:02 +0200 [thread overview]
Message-ID: <20110526101102.GF9715@htj.dyndns.org> (raw)
In-Reply-To: <201105261101.43237.pedro@codesourcery.com>
Hello, Pedro.
On Thu, May 26, 2011 at 11:01:42AM +0100, Pedro Alves wrote:
> SYSGOOD makes sense, it just enables a means to distinguish syscall
> SIGTRAPs from regular SIGTRAPs -- it doesn't cause child stops itself.
> TRACE_EXEC, I'm not so sure. (and it appears to have been proposed
> on the premise that SEIZE would still report the SIGTRAP).
> Why would that make sense, and not TRACE_FORK, for example? I can imagine
> a tracer only caring for syscall entry/exit, and not needing a special
> event on exec. IMO, any kind of event that forces a child stop that
> would't happen if the child wasn't traced should have to be enabled
> explicitly.
The problem with exec is that very weird things happen during exec.
Tasks change their ids, tracees get silently pruned and so on, so
there might not be a transparent way for a ptracer to deal with it.
It needs to be notified and handle the situation whether it wants or
not.
What I was saying was there won't be SIGTRAP. In general, we're
trying to move away from kernel implicitly sending actual signals. If
we enable it by default, it will be a proper ptrace trap.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-05-26 10:11 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-16 18:17 [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification, take#2 Tejun Heo
2011-05-16 18:17 ` [PATCH 01/10] signal: remove three noop tracehooks Tejun Heo
2011-05-17 16:22 ` Christoph Hellwig
2011-05-17 16:27 ` Tejun Heo
2011-05-18 18:45 ` Oleg Nesterov
2011-05-19 12:11 ` Tejun Heo
2011-05-19 16:10 ` Oleg Nesterov
2011-05-16 18:17 ` [PATCH 02/10] job control: introduce JOBCTL_TRAP_STOP and use it for group stop trap Tejun Heo
2011-05-18 16:48 ` Oleg Nesterov
2011-05-18 16:57 ` Oleg Nesterov
2011-05-19 10:19 ` Tejun Heo
2011-05-19 16:19 ` Oleg Nesterov
2011-05-16 18:17 ` [PATCH 03/10] ptrace: implement PTRACE_SEIZE Tejun Heo
2011-05-18 0:40 ` Denys Vlasenko
2011-05-18 9:55 ` Tejun Heo
2011-05-18 10:44 ` Denys Vlasenko
2011-05-18 11:14 ` Tejun Heo
2011-05-19 14:17 ` Tejun Heo
2011-05-19 15:02 ` Tejun Heo
2011-05-19 19:31 ` Pedro Alves
2011-05-19 22:42 ` Denys Vlasenko
2011-05-19 23:00 ` Pedro Alves
2011-05-20 1:44 ` Denys Vlasenko
2011-05-20 8:56 ` Pedro Alves
2011-05-20 9:12 ` Tejun Heo
2011-05-20 9:07 ` Tejun Heo
2011-05-20 9:27 ` Pedro Alves
2011-05-20 9:31 ` Tejun Heo
2011-05-24 9:49 ` Pedro Alves
2011-05-24 12:00 ` Tejun Heo
2011-05-24 12:36 ` Pedro Alves
2011-05-24 14:02 ` Tejun Heo
2011-05-24 14:55 ` Pedro Alves
2011-05-25 18:18 ` Oleg Nesterov
2011-05-26 9:10 ` Tejun Heo
2011-05-26 10:01 ` Pedro Alves
2011-05-26 10:11 ` Tejun Heo [this message]
2011-05-26 14:55 ` Oleg Nesterov
2011-05-23 13:09 ` Oleg Nesterov
2011-05-23 12:43 ` Oleg Nesterov
2011-05-24 10:28 ` Tejun Heo
2011-05-25 18:29 ` Oleg Nesterov
2011-05-26 9:14 ` Tejun Heo
2011-05-26 15:01 ` Oleg Nesterov
2011-05-27 18:21 ` Tejun Heo
2011-05-30 19:22 ` Oleg Nesterov
[not found] ` <BANLkTimupSd774N-VBoswOj+Dza=5ofvWQ@mail.gmail.com>
2011-05-31 19:08 ` Oleg Nesterov
2011-05-31 21:32 ` Linus Torvalds
2011-06-01 20:04 ` Oleg Nesterov
2011-06-01 5:34 ` Tejun Heo
2011-06-01 20:08 ` Oleg Nesterov
2011-06-02 5:01 ` Tejun Heo
2011-05-18 18:17 ` Oleg Nesterov
2011-05-19 10:34 ` Tejun Heo
2011-05-16 18:17 ` [PATCH 04/10] ptrace: implement PTRACE_INTERRUPT Tejun Heo
2011-05-18 18:38 ` Oleg Nesterov
2011-05-19 12:07 ` Tejun Heo
2011-05-19 16:21 ` Oleg Nesterov
2011-05-16 18:17 ` [PATCH 05/10] ptrace: restructure ptrace_getsiginfo() Tejun Heo
2011-05-16 18:17 ` [PATCH 06/10] ptrace: add siginfo.si_pt_flags Tejun Heo
2011-05-16 18:17 ` [PATCH 07/10] ptrace: make group stop state visible via PTRACE_GETSIGINFO Tejun Heo
2011-05-19 16:27 ` Oleg Nesterov
2011-05-19 16:40 ` Tejun Heo
2011-05-16 18:17 ` [PATCH 08/10] ptrace: don't let PTRACE_SETSIGINFO override __SI_TRAP siginfo Tejun Heo
2011-05-16 18:17 ` [PATCH 09/10] ptrace: add JOBCTL_BLOCK_NOTIFY Tejun Heo
2011-05-19 16:32 ` Oleg Nesterov
2011-05-19 16:44 ` Tejun Heo
2011-05-19 16:48 ` Oleg Nesterov
2011-05-19 16:58 ` Tejun Heo
2011-05-16 18:17 ` [PATCH 10/10] ptrace: implement group stop notification for ptracer Tejun Heo
2011-05-19 16:32 ` Oleg Nesterov
2011-05-19 16:57 ` Tejun Heo
2011-05-19 17:13 ` Oleg Nesterov
2011-05-19 22:48 ` Denys Vlasenko
2011-05-20 8:59 ` Tejun Heo
2011-05-23 13:34 ` Oleg Nesterov
2011-05-20 8:46 ` Tejun Heo
2011-05-19 16:58 ` Oleg Nesterov
2011-05-23 11:45 ` Oleg Nesterov
2011-05-24 13:44 ` Tejun Heo
2011-05-24 15:44 ` Tejun Heo
2011-05-26 14:44 ` Oleg Nesterov
2011-05-28 7:32 ` Tejun Heo
2011-05-18 18:50 ` [PATCHSET ptrace] ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification, take#2 Oleg Nesterov
2011-05-19 12:08 ` Tejun Heo
2011-05-19 15:04 ` Linus Torvalds
2011-05-19 15:19 ` Tejun Heo
2011-05-19 22:45 ` Denys Vlasenko
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=20110526101102.GF9715@htj.dyndns.org \
--to=tj@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=bdonlan@gmail.com \
--cc=indan@nul.nu \
--cc=jan.kratochvil@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=pedro@codesourcery.com \
--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).