All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Aleksa Sarai <asarai@suse.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Attila Fazekas <afazekas@redhat.com>, Jann Horn <jann@thejh.net>,
	Kees Cook <keescook@chromium.org>,
	Michal Hocko <mhocko@kernel.org>,
	Ulrich Obergfell <uobergfe@redhat.com>,
	linux-kernel@vger.kernel.org, linux-api@vger.kernel.org
Subject: Re: [RFC][PATCH 2/2] exec: If possible don't wait for ptraced threads to be reaped
Date: Wed, 5 Apr 2017 18:44:30 +0200	[thread overview]
Message-ID: <20170405164429.GG14536@redhat.com> (raw)
In-Reply-To: <87inmlnqx1.fsf@xmission.com>

On 04/03, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@redhat.com> writes:
>
> > I meant that may_hang == 0 implies zap_other_threads(do_count => -1) which should
> > return the number of threads which didn't pass exit_notify(). The returned value
> > can be wrong unless you change exit_notify() to set exit_state under
> > siglock.

but I forgot to add that, of course, this problem is very minor because
we can only miss a thread which is already at the end of exit_notify()
so nothing bad can happen.

But imo should be fixed anyway, simply because this looks wrong/racy.
Your recent 4/5 has the same problem.

> Interesting an existing bug.

Hmm... what do you mean? The current code looks fine.

Oleg.

  reply	other threads:[~2017-04-05 16:45 UTC|newest]

Thread overview: 93+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-13 14:14 [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
2017-02-13 14:15 ` [PATCH 1/2] exec: don't wait for zombie threads with cred_guard_mutex held Oleg Nesterov
2017-02-13 16:12   ` kbuild test robot
2017-02-13 16:47     ` Oleg Nesterov
2017-02-13 16:39   ` kbuild test robot
2017-02-13 17:27   ` Mika Penttilä
2017-02-13 18:01     ` Oleg Nesterov
2017-02-13 18:04   ` [PATCH V2 " Oleg Nesterov
2017-02-16 11:42     ` Eric W. Biederman
2017-02-20 15:22       ` Oleg Nesterov
2017-02-20 15:36         ` Oleg Nesterov
2017-02-20 22:30         ` Eric W. Biederman
2017-02-21 17:53           ` Oleg Nesterov
2017-02-21 20:20             ` Eric W. Biederman
2017-02-22 17:41               ` Oleg Nesterov
2017-02-17  4:42     ` Eric W. Biederman
2017-02-20 15:50       ` Oleg Nesterov
2017-02-13 14:15 ` [PATCH 2/2] ptrace: ensure PTRACE_EVENT_EXIT won't stop if the tracee is killed by exec Oleg Nesterov
2017-02-24 16:03 ` [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
2017-03-03  1:05   ` Eric W. Biederman
2017-03-03 17:33     ` Oleg Nesterov
2017-03-03 18:23       ` Eric W. Biederman
2017-03-03 18:23         ` Eric W. Biederman
2017-03-03 18:59         ` Eric W. Biederman
2017-03-03 18:59           ` Eric W. Biederman
2017-03-03 20:06           ` Eric W. Biederman
2017-03-03 20:06             ` Eric W. Biederman
2017-03-03 20:11             ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Eric W. Biederman
2017-03-03 20:11               ` Eric W. Biederman
2017-03-04 17:03               ` Oleg Nesterov
2017-03-30  8:07                 ` Eric W. Biederman
2017-04-01  5:11                   ` [RFC][PATCH 0/2] exec: Fixing ptrace'd mulit-threaded hang Eric W. Biederman
2017-04-01  5:11                     ` Eric W. Biederman
2017-04-01  5:14                     ` [RFC][PATCH 1/2] sighand: Count each thread group once in sighand_struct Eric W. Biederman
2017-04-01  5:14                       ` Eric W. Biederman
2017-04-01  5:16                     ` [RFC][PATCH 2/2] exec: If possible don't wait for ptraced threads to be reaped Eric W. Biederman
2017-04-01  5:16                       ` Eric W. Biederman
2017-04-02 15:35                       ` Oleg Nesterov
2017-04-02 15:35                         ` Oleg Nesterov
2017-04-02 18:53                         ` Eric W. Biederman
2017-04-02 18:53                           ` Eric W. Biederman
2017-04-03 18:12                           ` Oleg Nesterov
2017-04-03 18:12                             ` Oleg Nesterov
2017-04-03 21:04                             ` Eric W. Biederman
2017-04-05 16:44                               ` Oleg Nesterov [this message]
2017-04-02 15:38                     ` [RFC][PATCH 0/2] exec: Fixing ptrace'd mulit-threaded hang Oleg Nesterov
2017-04-02 15:38                       ` Oleg Nesterov
2017-04-02 22:50                     ` [RFC][PATCH v2 0/5] " Eric W. Biederman
2017-04-02 22:50                       ` Eric W. Biederman
2017-04-02 22:51                       ` [RFC][PATCH v2 1/5] ptrace: Don't wait in PTRACE_O_TRACEEXIT for exec or coredump Eric W. Biederman
2017-04-02 22:51                         ` Eric W. Biederman
2017-04-05 16:19                         ` Oleg Nesterov
2017-04-02 22:51                       ` [RFC][PATCH v2 2/5] sighand: Count each thread group once in sighand_struct Eric W. Biederman
2017-04-02 22:51                         ` Eric W. Biederman
2017-04-02 22:52                       ` [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct Eric W. Biederman
2017-04-02 22:52                         ` Eric W. Biederman
2017-04-05 16:24                         ` Oleg Nesterov
2017-04-05 16:24                           ` Oleg Nesterov
2017-04-05 17:34                           ` Eric W. Biederman
2017-04-05 18:11                             ` Oleg Nesterov
2017-04-02 22:53                       ` [RFC][PATCH v2 4/5] exec: If possible don't wait for ptraced threads to be reaped Eric W. Biederman
2017-04-02 22:53                         ` Eric W. Biederman
2017-04-05 16:15                         ` Oleg Nesterov
2017-04-02 22:57                       ` [RFC][PATCH v2 5/5] signal: Don't allow accessing signal_struct by old threads after exec Eric W. Biederman
2017-04-02 22:57                         ` Eric W. Biederman
2017-04-05 16:18                         ` Oleg Nesterov
2017-04-05 16:18                           ` Oleg Nesterov
2017-04-05 18:16                           ` Eric W. Biederman
2017-04-05 18:16                             ` Eric W. Biederman
2017-04-06 15:48                             ` Oleg Nesterov
2017-04-06 15:48                               ` Oleg Nesterov
2017-04-02 16:15                   ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Oleg Nesterov
2017-04-02 16:15                     ` Oleg Nesterov
2017-04-02 21:07                     ` Eric W. Biederman
2017-04-02 21:07                       ` Eric W. Biederman
2017-04-03 18:37                       ` Oleg Nesterov
2017-04-03 18:37                         ` Oleg Nesterov
2017-04-03 22:49                         ` Eric W. Biederman
2017-04-03 22:49                           ` Eric W. Biederman
2017-04-03 22:49                         ` scope of cred_guard_mutex Eric W. Biederman
2017-04-03 22:49                           ` Eric W. Biederman
2017-04-05 16:08                           ` Oleg Nesterov
2017-04-05 16:11                             ` Kees Cook
2017-04-05 17:53                             ` Eric W. Biederman
2017-04-05 18:15                               ` Oleg Nesterov
2017-04-06 15:55                           ` Oleg Nesterov
2017-04-06 15:55                             ` Oleg Nesterov
2017-04-07 22:07                             ` Kees Cook
2017-04-07 22:07                               ` Kees Cook
2017-09-04  3:19                       ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Robert O'Callahan
2017-09-04  3:19                         ` Robert O'Callahan
2017-03-04 16:54         ` [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
2017-03-04 16:54           ` Oleg Nesterov

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=20170405164429.GG14536@redhat.com \
    --to=oleg@redhat.com \
    --cc=afazekas@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=asarai@suse.com \
    --cc=ebiederm@xmission.com \
    --cc=jann@thejh.net \
    --cc=keescook@chromium.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=mhocko@kernel.org \
    --cc=uobergfe@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.