From: David Rientjes <rientjes@google.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Sergey Dyasly <dserrg@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.cz>,
Rusty Russell <rusty@rustcorp.com.au>,
Sha Zhengju <handai.szj@taobao.com>
Subject: Re: [PATCH] OOM killer: wait for tasks with pending SIGKILL to exit
Date: Mon, 9 Sep 2013 13:11:06 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.02.1309091307170.12523@chino.kir.corp.google.com> (raw)
In-Reply-To: <20130909163109.GA9334@redhat.com>
On Mon, 9 Sep 2013, Oleg Nesterov wrote:
> > @@ -275,13 +275,16 @@ enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
> > if (oom_task_origin(task))
> > return OOM_SCAN_SELECT;
> >
> > - if (task->flags & PF_EXITING && !force_kill) {
> > + if ((task->flags & PF_EXITING || fatal_signal_pending(task)) &&
> > + !force_kill) {
> > /*
> > * If this task is not being ptraced on exit, then wait for it
> > * to finish before killing some other task unnecessarily.
> > */
> > - if (!(task->group_leader->ptrace & PT_TRACE_EXIT))
> > + if (!(task->group_leader->ptrace & PT_TRACE_EXIT)) {
>
> can't we finally kill (or fix?) this PT_TRACE_EXIT check?
>
Patches are always welcome.
> It was added to fix the exploit I sent. But the patch was wrong,
> that exploit could be easily modified to trigger the same problem.
>
If the patch prevented your exploit when coredumping was done differently
then it was not wrong. It may not have been as inclusive as you would
have liked, but then again you never proposed any kernel changes to fix it
yourself either.
> However, now that the coredumping is killable that exploit won't
> work, so the original reason has gone away.
>
> So why do we need this check today?
>
If you feel it can be removed, please propose a patch to do so with a
changelog that describes why it is no longer necessary.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-09-09 20:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-09 15:30 Sergey Dyasly
2013-09-09 16:31 ` Oleg Nesterov
2013-09-09 20:11 ` David Rientjes [this message]
2013-09-09 20:07 ` David Rientjes
2013-09-11 15:06 ` Sergey Dyasly
2013-09-19 15:51 ` Sergey Dyasly
2013-09-25 20:31 ` David Rientjes
2013-09-27 14:58 ` Sergey Dyasly
2013-09-30 22:08 ` David Rientjes
2013-10-01 15:26 ` Sergey Dyasly
2013-10-01 22:46 ` David Rientjes
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=alpine.DEB.2.02.1309091307170.12523@chino.kir.corp.google.com \
--to=rientjes@google.com \
--cc=akpm@linux-foundation.org \
--cc=dserrg@gmail.com \
--cc=handai.szj@taobao.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.cz \
--cc=oleg@redhat.com \
--cc=rusty@rustcorp.com.au \
/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