public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Daniel Walker <dwalker@fifo99.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: linux-kernel@vger.kernel.org
Subject: ptracing a task from core_pattern pipe
Date: Fri, 15 Mar 2013 18:15:09 -0700	[thread overview]
Message-ID: <20130316011508.GA11010@fifo99.com> (raw)

Hi,

I was writing an application to ptrace a process which is dumping core
from inside the pipe application for core_pattern.

So for example you make core pattern equal to something like
"|/bin/corepipe_app" then the kernel runs that app prior to actually
killing the process that failed.

Before the pipe application runs it puts SIGKILL on the pending signal
list for the failed application. However the application can't run.

This commit,

9899d11f654474d2d54ea52ceaa2a1f4db3abd68

seems to put a damper on ptracing the application at this point.

So I wanted to see what you think of all this.. Can we add an exception
to this which would allow operations on a task which is dumping core,
but still has SIGKILL pending. The other way would be to not add SIGKILL
till after the pipe app runs.

As of right now I can PTRACE_ATTACH, but the operations all fail with
-ESRCH .

Daniel


             reply	other threads:[~2013-03-16  1:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-16  1:15 Daniel Walker [this message]
2013-03-16 17:58 ` ptracing a task from core_pattern pipe Oleg Nesterov
2013-03-17  0:44   ` Daniel Walker
2013-03-17 14:34     ` Oleg Nesterov
2013-03-17 21:11       ` Daniel Walker
2013-03-18 17:03         ` Oleg Nesterov
2013-03-18 19:09           ` Daniel Walker
2013-03-19 20:19             ` Oleg Nesterov
2013-03-25  9:48               ` Denys Vlasenko
2013-03-27  3:26                 ` Daniel Walker
2013-03-27 12:17                   ` 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=20130316011508.GA11010@fifo99.com \
    --to=dwalker@fifo99.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=oleg@redhat.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