From: Mike Galbraith <efault@gmx.de>
To: Nicholas Mc Guire <der.herr@hofr.at>
Cc: linux-kernel@vger.kernel.org
Subject: Re: problem with signal delivery SIGCHLD
Date: Wed, 20 Dec 2006 08:10:15 +0100 [thread overview]
Message-ID: <1166598615.1614.55.camel@Homer.simpson.net> (raw)
In-Reply-To: <Pine.LNX.4.60.0612181924470.2560@rtl14.hofr.at>
On Mon, 2006-12-18 at 20:05 +0100, Nicholas Mc Guire wrote:
>
> Hi !
>
> I have a phenomena that I don't quite understand. gdbserver forks and
> after setting ptrace (PTRACE_TRACEME, 0, 0, 0); it then execv
> (program, allargs); when this child process hits ptrace_stoped (breakpoint
> it does the following in kernel space:
>
> pid 1242 = child process
> pid 1241 = gdbserver
> pid 0 = kernel
> pid -1 = interrupt
> pid
> 1 559 5 1242 ptrace_stop
> 3 6 2 1242 | do_notify_parent_cldstop
> 4 3 2 1242 | | __group_send_sig_info
> 5 1 1 1242 | | | handle_stop_signal
> 7 0 0 1242 | | | sig_ignored
> 8 1 0 1242 | | __wake_up_sync
> 8 1 1 1242 | | | __wake_up_common
> 10 547 541 1242 | schedule
> 10 2 2 1242 | | profile_hit
> 13 1 1 1242 | | sched_clock
> 15 1 0 1242 | | deactivate_task
> 15 1 1 1242 | | | dequeue_task
> 19 2 2 0 | | __switch_to
> ----------- !!!! start --------------
> 24 574 574 0 default_idle
> ----------- $$$$ end ----------------
> ----------- //// start --------------
> 780 41 12 0 do_IRQ
> 780 29 2 -1 / __do_IRQ
> ...
> 807 2 2 -1 / / / enable_8259A_irq
> ----------- //// end ----------------
> ----------- {{{{ start --------------
> 810 11 0 0 do_softirq
> ...
> 820 0 0 -1 { { { preempt_schedule
> ----------- {{{{ end ----------------
> ----------- %%%% start --------------
> 822 358 1 0 preempt_schedule_irq
> ...
> 827 1 1 1241 % % __switch_to
> ----------- %%%% end ----------------
> 829 1 1 1241 ( ( ( del_timer
> ----------- (((( end ----------------
> ----------- ]]]] start --------------
> 837 8 2 1241 sys_waitpid
>
> So basically child signals -> delayed to next tick -> parent wakes up.
Hm. What does the trace of gdbserver look like prior to the clild doing
do_notify_parent_cldstop()? Sleeping someplace other than wait4?
-Mike
next prev parent reply other threads:[~2006-12-20 7:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-18 19:05 Nicholas Mc Guire
2006-12-20 7:10 ` Mike Galbraith [this message]
2006-12-19 17:55 Chuck Ebbert
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=1166598615.1614.55.camel@Homer.simpson.net \
--to=efault@gmx.de \
--cc=der.herr@hofr.at \
--cc=linux-kernel@vger.kernel.org \
/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
all inboxes | Powered by JetHome®