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From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: roland@redhat.com, linux-kernel@vger.kernel.org,
	torvalds@linux-foundation.org, akpm@linux-foundation.org,
	rjw@sisk.pl, jan.kratochvil@redhat.com
Subject: Re: [PATCH 04/16] ptrace: kill tracehook_notify_jctl()
Date: Mon, 20 Dec 2010 15:59:56 +0100	[thread overview]
Message-ID: <20101220145956.GC11583@redhat.com> (raw)
In-Reply-To: <1291654624-6230-5-git-send-email-tj@kernel.org>

On 12/06, Tejun Heo wrote:
>
> tracehook_notify_jctl() aids in determining whether and what to report
> to the parent when a task is stopped or continued.  The function also
> adds an extra requirement that siglock may be released across it,
> which is currently unused and quite difficult to satisfy in
> well-defined manner.

OK. I agree, tracehook_notify_jctl() looks very unobvious, especially
because it is not really used currently.

The patch looks correct, except

> @@ -1853,21 +1850,19 @@ relock:
>  	if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
>  		int why;
>
> -		if (signal->flags & SIGNAL_CLD_CONTINUED)
> +		if (task_ptrace(current) ||
> +		    (signal->flags & SIGNAL_CLD_CONTINUED))
>  			why = CLD_CONTINUED;
>  		else
>  			why = CLD_STOPPED;

Hmm, I can't understand this.

task_ptrace() should not turn CLD_STOPPED in CLD_CONTINUED?

Looking ahead, it _seems_ that the next patches keep this logic,
could you explain?

Oleg.


  reply	other threads:[~2010-12-20 15:06 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-06 16:56 [PATCHSET] ptrace,signal: sane interaction between ptrace and job control signals, take#2 Tejun Heo
2010-12-06 16:56 ` [PATCH 01/16] signal: fix SIGCONT notification code Tejun Heo
2010-12-06 16:56 ` [PATCH 02/16] signal: fix CLD_CONTINUED notification target Tejun Heo
2010-12-20 14:58   ` Oleg Nesterov
2010-12-21 16:31     ` Tejun Heo
2010-12-06 16:56 ` [PATCH 03/16] signal: remove superflous try_to_freeze() loop in do_signal_stop() Tejun Heo
2010-12-20 14:59   ` Oleg Nesterov
2010-12-06 16:56 ` [PATCH 04/16] ptrace: kill tracehook_notify_jctl() Tejun Heo
2010-12-20 14:59   ` Oleg Nesterov [this message]
2010-12-21 17:00     ` Tejun Heo
2010-12-06 16:56 ` [PATCH 05/16] ptrace: add @why to ptrace_stop() Tejun Heo
2010-12-06 16:56 ` [PATCH 06/16] signal: fix premature completion of group stop when interfered by ptrace Tejun Heo
2010-12-20 15:00   ` Oleg Nesterov
2010-12-21 17:04     ` Tejun Heo
2010-12-06 16:56 ` [PATCH 07/16] signal: use GROUP_STOP_PENDING to stop once for a single group stop Tejun Heo
2010-12-06 16:56 ` [PATCH 08/16] ptrace: participate in group stop from ptrace_stop() iff the task is trapping for " Tejun Heo
2010-12-06 16:56 ` [PATCH 09/16] ptrace: make do_signal_stop() use ptrace_stop() if the task is being ptraced Tejun Heo
2010-12-23 12:26   ` Oleg Nesterov
2010-12-23 13:53     ` Tejun Heo
2010-12-23 16:06       ` Oleg Nesterov
2010-12-23 16:33         ` Tejun Heo
2011-01-17 22:09     ` Roland McGrath
2011-01-27 13:56       ` Tejun Heo
2011-01-28 20:30         ` Roland McGrath
2011-01-31 14:39           ` Tejun Heo
2010-12-06 16:56 ` [PATCH 10/16] ptrace: clean transitions between TASK_STOPPED and TRACED Tejun Heo
2010-12-20 15:00   ` Oleg Nesterov
2010-12-21 17:31     ` Tejun Heo
2010-12-21 17:32       ` Tejun Heo
2010-12-22 10:54       ` Tejun Heo
2010-12-22 11:39       ` Oleg Nesterov
2010-12-22 15:14         ` Tejun Heo
2010-12-22 16:00           ` Oleg Nesterov
2010-12-22 16:21             ` Tejun Heo
2010-12-06 16:56 ` [PATCH 11/16] signal: prepare for CLD_* notification changes Tejun Heo
2010-12-20 16:21   ` Oleg Nesterov
2010-12-20 16:23     ` Oleg Nesterov
2010-12-21 17:35     ` Tejun Heo
2010-12-06 16:57 ` [PATCH 12/16] ptrace: make group stop notification reliable against ptrace Tejun Heo
2010-12-20 17:34   ` Oleg Nesterov
2010-12-21 17:43     ` Tejun Heo
2010-12-22 11:54       ` Oleg Nesterov
2010-12-22 15:26         ` Tejun Heo
2010-12-22 16:02           ` Oleg Nesterov
2010-12-06 16:57 ` [PATCH 13/16] ptrace: reorganize __ptrace_unlink() and ptrace_untrace() Tejun Heo
2010-12-20 18:15   ` Oleg Nesterov
2010-12-21 17:54     ` Tejun Heo
2010-12-06 16:57 ` [PATCH 14/16] ptrace: make SIGCONT notification reliable against ptrace Tejun Heo
2010-12-20 19:43   ` Oleg Nesterov
2010-12-21 17:48     ` Tejun Heo
2010-12-22 12:16       ` Oleg Nesterov
2010-12-21 17:25   ` Oleg Nesterov
2010-12-22 10:35     ` Tejun Heo
2010-12-06 16:57 ` [PATCH 15/16] ptrace: make sure SIGNAL_NOTIFY_CONT is checked after ptrace_signal() Tejun Heo
2010-12-06 16:57 ` [PATCH 16/16] ptrace: remove the extra wake_up_process() from ptrace_detach() Tejun Heo
2010-12-07  0:10   ` Roland McGrath
2010-12-07 13:43     ` Tejun Heo
2010-12-21 17:54   ` Oleg Nesterov
2010-12-22 10:36     ` Tejun Heo
2010-12-14 17:36 ` [PATCHSET] ptrace,signal: sane interaction between ptrace and job control signals, take#2 Oleg Nesterov
2010-12-14 17:46   ` Tejun Heo
2010-12-22 15:20 ` Oleg Nesterov

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