All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: rjw@rjwysocki.net, mingo@kernel.org, vincent.guittot@linaro.org,
	dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de,
	ebiederm@xmission.com, bigeasy@linutronix.de,
	Will Deacon <will@kernel.org>,
	linux-kernel@vger.kernel.org, tj@kernel.org,
	linux-pm@vger.kernel.org
Subject: Re: [PATCH 2/5] sched,ptrace: Fix ptrace_check_attach() vs PREEMPT_RT
Date: Wed, 20 Apr 2022 13:35:48 +0200	[thread overview]
Message-ID: <20220420113547.GA16575@redhat.com> (raw)
In-Reply-To: <20220420102006.GD2731@worktop.programming.kicks-ass.net>

On 04/20, Peter Zijlstra wrote:
>
> On Fri, Apr 15, 2022 at 12:57:56PM +0200, Oleg Nesterov wrote:
> >
> > ptrace_resume() does  wake_up_state(child, __TASK_TRACED) but doesn't
> > clear JOBCTL_TRACED. The "else" branch in ptrace_stop() leaks this flag
> > too. Perhaps I missed something, I'll reread 1/5 again, but the main
> > question to me is whether 1-2 actually need the JOBCTL_TRACED_FROZEN flag.
>
> Ok, getting back to this. So I did the change to ptrace_resume(), but
> I'm not entirely sure I understand the issue with the else branch of
> ptrace_stop().
>
> My understanding is that if we hit that else branch, we've raced wth
> __ptrace_unlink(), and that will have done:

Yes, thanks for correcting me, I forgot that may_ptrace_stop() has gone.

Oleg.


  reply	other threads:[~2022-04-20 11:36 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-12 11:44 [PATCH 0/5] ptrace-vs-PREEMPT_RT and freezer rewrite Peter Zijlstra
2022-04-12 11:44 ` [PATCH 1/5] sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state Peter Zijlstra
2022-04-13 13:29   ` Oleg Nesterov
2022-04-13 16:47     ` Peter Zijlstra
2022-04-12 11:44 ` [PATCH 2/5] sched,ptrace: Fix ptrace_check_attach() vs PREEMPT_RT Peter Zijlstra
2022-04-13 13:24   ` Oleg Nesterov
2022-04-13 16:58     ` Peter Zijlstra
2022-04-13 18:57     ` Oleg Nesterov
2022-04-13 18:59       ` Oleg Nesterov
2022-04-13 19:20         ` Peter Zijlstra
2022-04-13 19:56           ` Peter Zijlstra
2022-04-14 11:54             ` Oleg Nesterov
2022-04-14 12:08               ` Oleg Nesterov
2022-04-14 18:34               ` Oleg Nesterov
2022-04-14 22:45                 ` Peter Zijlstra
2022-04-15 10:16                   ` Oleg Nesterov
2022-04-15 10:57                     ` Oleg Nesterov
2022-04-15 12:01                       ` Peter Zijlstra
2022-04-18 17:01                         ` Oleg Nesterov
2022-04-18 17:19                           ` Oleg Nesterov
2022-04-20 13:17                           ` Peter Zijlstra
2022-04-20 18:03                             ` Oleg Nesterov
2022-04-20 20:54                               ` [RFC][PATCH] ptrace: Don't change __state Eric W. Biederman
2022-04-21  7:21                                 ` Peter Zijlstra
2022-04-21 10:26                                   ` Peter Zijlstra
2022-04-21 10:49                                     ` Oleg Nesterov
2022-04-21 11:50                                       ` Peter Zijlstra
2022-04-21 14:45                                   ` Eric W. Biederman
2022-04-21  9:46                                 ` Oleg Nesterov
2022-04-21 15:01                                   ` Eric W. Biederman
2022-04-21 11:46                                 ` kernel test robot
2022-04-27  0:51                                 ` [ptrace] [confidence: ] 7d3fafb751: BUG:sleeping_function_called_from_invalid_context_at_arch/x86/entry/common.c kernel test robot
2022-04-27  0:51                                   ` kernel test robot
2022-04-20 10:20                       ` [PATCH 2/5] sched,ptrace: Fix ptrace_check_attach() vs PREEMPT_RT Peter Zijlstra
2022-04-20 11:35                         ` Oleg Nesterov [this message]
2022-04-15 12:00                     ` Peter Zijlstra
2022-04-15 12:56                       ` Oleg Nesterov
2022-04-12 11:44 ` [PATCH 3/5] freezer: Have {,un}lock_system_sleep() save/restore flags Peter Zijlstra
2022-04-12 11:44 ` [PATCH 4/5] freezer,umh: Clean up freezer/initrd interaction Peter Zijlstra
2022-04-12 11:44 ` [PATCH 5/5] freezer,sched: Rewrite core freezer logic Peter Zijlstra

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=20220420113547.GA16575@redhat.com \
    --to=oleg@redhat.com \
    --cc=bigeasy@linutronix.de \
    --cc=dietmar.eggemann@arm.com \
    --cc=ebiederm@xmission.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rjw@rjwysocki.net \
    --cc=rostedt@goodmis.org \
    --cc=tj@kernel.org \
    --cc=vincent.guittot@linaro.org \
    --cc=will@kernel.org \
    /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.