From: Oleg Nesterov <oleg@tv-sign.ru>
To: Matthew Wilcox <matthew@wil.cx>
Cc: Roland McGrath <roland@redhat.com>,
Petr Tesarik <ptesarik@suse.cz>, Tony Luck <tony.luck@intel.com>,
Matthew Wilcox <willy@debian.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arch_ptrace_stop
Date: Thu, 13 Dec 2007 20:39:56 +0300 [thread overview]
Message-ID: <20071213173956.GA436@tv-sign.ru> (raw)
In-Reply-To: <20071213173136.GO26334@parisc-linux.org>
On 12/13, Matthew Wilcox wrote:
>
> On Thu, Dec 13, 2007 at 08:29:26PM +0300, Oleg Nesterov wrote:
> > How is it possible that SIGKILL is blocked?
>
> I *think* it's possible that kernel threads may block SIGKILL.
> And I think init (pid 1) gets SIGKILL blocked.
Yes. But this shouldn't matter because we can't ptrace them. /sbin/init
doesn't block SIGKILL, but it can't be ptraced either.
Also, SIGKILL is blocked only if kthread was created by kernel_thread() and
then it does daemonize(). kthread_create()'ed kthreads don't block SIGKILL
but ignore it. The latter behaviour is more correct, but we can't do the same
for kernel_thread() threads.
Oleg.
next prev parent reply other threads:[~2007-12-13 17:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-13 17:29 [PATCH] arch_ptrace_stop Oleg Nesterov
2007-12-13 17:31 ` Matthew Wilcox
2007-12-13 17:39 ` Oleg Nesterov [this message]
2007-12-13 22:42 ` Roland McGrath
2007-12-16 16:24 ` Oleg Nesterov
[not found] <1196959793.6586.3.camel@elijah.suse.cz>
2007-12-08 1:11 ` Roland McGrath
2007-12-12 5:51 ` Andrew Morton
2007-12-12 22:36 ` Roland McGrath
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