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From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Aaron Tomlin <atomlin@redhat.com>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Sterling Alexander <stalexan@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 0/4] proc: deuglify task_state()
Date: Fri, 7 Nov 2014 21:14:24 +0100	[thread overview]
Message-ID: <20141107201424.GA22209@redhat.com> (raw)

Hello.

I tried to optimize the usage of tasklist_lock in exit_notify() paths
but found the bug which should be fixed first: the EXIT_DEAD setting
in reparent_leader() can break the task_ppid_nr_ns()-like code and
ptrace_parent().

I am still thinking about the "right" fix, but whatever we do we need
to cleanup these users, probably before the fix.

One particular user is task_state(), but it also asks for other off-
topic cleanups which I believe make sense anyway, lets do this first.

Oleg.

 fs/proc/array.c |   47 ++++++++++++++++++++++-------------------------
 1 files changed, 22 insertions(+), 25 deletions(-)


             reply	other threads:[~2014-11-07 20:14 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-07 20:14 Oleg Nesterov [this message]
2014-11-07 20:14 ` [PATCH 1/4] proc: task_state: read cred->group_info outside of task_lock() Oleg Nesterov
2014-11-07 20:14 ` [PATCH 2/4] proc: task_state: deuglify the max_fds calculation Oleg Nesterov
2014-11-07 20:14 ` [PATCH 3/4] proc: task_state: move the main seq_printf() outside of rcu_read_lock() Oleg Nesterov
2014-11-13 18:04   ` Paul E. McKenney
2014-11-07 20:14 ` [PATCH 4/4] proc: task_state: ptrace_parent() doesn't need pid_alive() check Oleg Nesterov
2014-11-10 21:59 ` [PATCH 0/5] exit: reparent zombie fix + cleanups/optimizations Oleg Nesterov
2014-11-10 22:00   ` [PATCH 1/5] sched_show_task: fix unsafe usage of ->real_parent Oleg Nesterov
2014-11-11 10:39     ` Peter Zijlstra
2014-11-10 22:00   ` [PATCH 2/5] exit: reparent: use ->ptrace_entry rather than ->sibling for EXIT_DEAD tasks Oleg Nesterov
2014-11-10 22:00   ` [PATCH 3/5] exit: reparent: cleanup the changing of ->parent Oleg Nesterov
2014-11-10 22:00   ` [PATCH 4/5] exit: reparent: cleanup the usage of reparent_leader() Oleg Nesterov
2014-11-10 22:00   ` [PATCH 5/5] exit: ptrace: shift "reap dead" code from exit_ptrace() to forget_original_parent() Oleg Nesterov
2014-11-14  1:37 ` [PATCH 0/5] exit: more cleanups/optimizations Oleg Nesterov
2014-11-14  1:38   ` [PATCH 1/5] exit: wait: cleanup the ptrace_reparented() checks Oleg Nesterov
2014-11-14  1:38   ` [PATCH 2/5] exit: wait: don't use zombie->real_parent Oleg Nesterov
2014-11-14  1:38   ` [PATCH 3/5] exit: wait: drop tasklist_lock before psig->c* accounting Oleg Nesterov
2014-11-14  1:38   ` [PATCH 4/5] exit: release_task: fix the comment about group leader accounting Oleg Nesterov
2014-11-14  1:38   ` [PATCH 5/5] exit: proc: don't try to flush /proc/tgid/task/tgid Oleg Nesterov
2014-11-18 21:29 ` [PATCH 0/6] exit: find_new_reaper() fixes/cleanups Oleg Nesterov
2014-11-18 21:30   ` [PATCH 1/6] exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting Oleg Nesterov
2014-11-18 21:30   ` [PATCH 2/6] exit: reparent: fix the cross-namespace " Oleg Nesterov
2014-11-18 21:30   ` [PATCH 3/6] exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper() Oleg Nesterov
2014-11-18 21:30   ` [PATCH 4/6] exit: reparent: document the ->has_child_subreaper checks Oleg Nesterov
2014-11-18 21:30   ` [PATCH 5/6] exit: reparent: introduce find_child_reaper() Oleg Nesterov
2014-11-18 21:30   ` [PATCH 6/6] exit: reparent: introduce find_alive_thread() Oleg Nesterov
2014-11-20 18:34 ` [PATCH 0/3] exit: avoid O(n ** 2) thread-list scan on group-exit if possible Oleg Nesterov
2014-11-20 18:34   ` [PATCH -mm 1/3] exit: reparent: avoid find_new_reaper() if no children Oleg Nesterov
2014-11-20 22:37     ` Andrew Morton
2014-11-21 20:01       ` Oleg Nesterov
2014-11-20 18:34   ` [PATCH -mm 2/3] exit: reparent: call forget_original_parent() under tasklist_lock Oleg Nesterov
2014-11-20 18:34   ` [PATCH -mm 3/3] exit: exit_notify: re-use "dead" list to autoreap current Oleg Nesterov
2014-11-24 20:06 ` [PATCH 0/2] exit/pid_ns: comments + simple fix Oleg Nesterov
2014-11-24 20:06   ` [PATCH 1/2] exit: reparent: fix/update the comments in zap_pid_ns_processes() Oleg Nesterov
2014-11-24 20:14     ` Oleg Nesterov
2014-11-24 22:07     ` Eric W. Biederman
2014-11-25 16:57       ` Oleg Nesterov
2014-11-25 17:17         ` Oleg Nesterov
2014-11-24 20:06   ` [PATCH 2/2] exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting Oleg Nesterov
2014-11-24 21:46     ` Eric W. Biederman
2014-11-25 17:07       ` Oleg Nesterov
2014-11-25 17:50         ` Eric W. Biederman
2014-11-25 18:15           ` Oleg Nesterov
2014-11-25 18:43             ` Eric W. Biederman
2014-11-25 18:59               ` Oleg Nesterov
2014-11-24 21:27   ` [PATCH 0/2] exit/pid_ns: comments + simple fix Eric W. Biederman
2014-11-24 21:38     ` Oleg Nesterov
2014-11-24 21:48   ` Eric W. Biederman
2014-11-25 16:57     ` Oleg Nesterov
2014-11-26 23:54   ` [PATCH v2 " Oleg Nesterov
2014-11-26 23:54     ` [PATCH v2 1/2] exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting Oleg Nesterov
2014-11-27 15:44       ` Eric W. Biederman
2014-11-26 23:54     ` [PATCH v2 2/2] exit: pidns: fix/update the comments in zap_pid_ns_processes() Oleg Nesterov
2014-12-01 22:39       ` Andrew Morton
2014-12-01 23:24         ` Oleg Nesterov

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