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 v2 4/5] exec: If possible don't wait for ptraced threads to be reaped
Date: Wed, 5 Apr 2017 18:15:28 +0200 [thread overview]
Message-ID: <20170405161528.GC14536@redhat.com> (raw)
In-Reply-To: <87efxa8lq7.fsf_-_@xmission.com>
On 04/02, Eric W. Biederman wrote:
>
> Take advantage of the situation when sighand->count == 1 to only wait
> for threads to reach EXIT_ZOMBIE instead of EXIT_DEAD in de_thread.
Let me comment this patch first, it looks mostly fine to me.
And note that this is what my patch does too: exec() waits until
all threads pass exit_notify() and drops cred_guard_mutex.
However, with my patch patch exec() then waits until all threads
disappear. This is uglifies the code but this is simple and safe.
With your patches exec doesn't do another wait and succeeds after
the 1st wait. I think this is wrong and the next patch is not enough.
Oleg.
next prev parent reply other threads:[~2017-04-05 16:16 UTC|newest]
Thread overview: 63+ 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 18:59 ` 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
2017-03-04 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 5:14 ` [RFC][PATCH 1/2] sighand: Count each thread group once in sighand_struct 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
2017-04-02 15:35 ` Oleg Nesterov
2017-04-02 18:53 ` Eric W. Biederman
2017-04-03 18:12 ` Oleg Nesterov
2017-04-03 21:04 ` Eric W. Biederman
2017-04-05 16:44 ` Oleg Nesterov
2017-04-02 15:38 ` [RFC][PATCH 0/2] exec: Fixing ptrace'd mulit-threaded hang Oleg Nesterov
2017-04-02 22:50 ` [RFC][PATCH v2 0/5] " 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
2017-04-05 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 22:52 ` [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct Eric W. Biederman
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
2017-04-05 16:15 ` Oleg Nesterov [this message]
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
2017-04-05 16:18 ` Oleg Nesterov
2017-04-05 18:16 ` Eric W. Biederman
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 21:07 ` Eric W. Biederman
2017-04-03 18:37 ` Oleg Nesterov
2017-04-03 22:49 ` Eric W. Biederman
2017-04-03 22:49 ` scope of cred_guard_mutex 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
2017-04-07 22:07 ` Kees Cook
2017-09-04 3:19 ` [RFC][PATCH] exec: Don't wait for ptraced threads to be reaped Robert O'Callahan
2017-03-04 16:54 ` [PATCH 0/2] fix the traced mt-exec deadlock Oleg Nesterov
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