From: Pedro Alves <palves@redhat.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Mike Frysinger <vapier@gentoo.org>,
"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>,
pacman@kosh.dhis.org, linux-man <linux-man@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Denys Vlasenko <dvlasenk@redhat.com>, Tejun Heo <tj@kernel.org>,
Jan Kratochvil <jan.kratochvil@redhat.com>
Subject: Re: ptrace.2: PTRACE_KILL needs a stopped process too
Date: Wed, 09 May 2012 23:08:15 +0100 [thread overview]
Message-ID: <4FAAEACF.3070405@redhat.com> (raw)
In-Reply-To: <20120509201219.GA32051@redhat.com>
On 05/09/2012 09:12 PM, Oleg Nesterov wrote:
> tgkill() can kill the wrong process/thread too, although it lessens the risk.
>
> But I don't really understand the problem. The traced thread can't go away
> until the tracer does wait/detach, and thus its pid can't be reused?
There's the non-leader thread execs and tracer didn't enable
PTRACE_O_TRACEEXEC case at least, while you try to kill the thread that just
execed, I think. Though that's quite pedantic. The tracer could prevent this
in other ways.
> May be, "by accident" above means something else, not pid reuse...
Pffft, who writes buggy code anyway? ;-)
--
Pedro Alves
prev parent reply other threads:[~2012-05-09 22:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20091216004533.22261.qmail@kosh.dhis.org>
[not found] ` <20091216004533.22261.qmail-ptgZXYu0fikgsBAKwltoeQ@public.gmane.org>
2012-04-22 18:56 ` ptrace.2: PTRACE_KILL needs a stopped process too Michael Kerrisk (man-pages)
[not found] ` <CAKgNAkhtu8d0NKcTwWyCA8qWgz8Lag+GcpEE1=YMVe_Nh8XJ9Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-22 20:04 ` Oleg Nesterov
[not found] ` <20120422200459.GA7519-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-05-02 12:06 ` Pedro Alves
2012-05-09 15:09 ` Mike Frysinger
[not found] ` <201205091109.35637.vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
2012-05-09 19:35 ` Pedro Alves
[not found] ` <4FAAC706.6000808-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-05-09 20:12 ` Oleg Nesterov
[not found] ` <20120509201219.GA32051-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-05-09 16:41 ` Mike Frysinger
2012-05-09 21:14 ` Oleg Nesterov
[not found] ` <20120509211429.GA2455-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-05-09 22:16 ` Pedro Alves
2012-05-09 22:08 ` Pedro Alves [this message]
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