Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753835Ab0FMLY6 (ORCPT ); Sun, 13 Jun 2010 07:24:58 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:48216 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753055Ab0FMLY4 (ORCPT ); Sun, 13 Jun 2010 07:24:56 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Oleg Nesterov Subject: Re: [PATCH 1/1] signals: introduce send_sigkill() helper Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , Roland McGrath , "Luis Claudio R. Goncalves" , LKML , linux-mm , David Rientjes , KAMEZAWA Hiroyuki , Nick Piggin , Minchan Kim In-Reply-To: <20100610010023.GB4727@redhat.com> References: <20100610005937.GA4727@redhat.com> <20100610010023.GB4727@redhat.com> Message-Id: <20100613184334.6181.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Sun, 13 Jun 2010 20:24:53 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1251 Lines: 32 > Cleanup, no functional changes. > > There are a lot of buggy SIGKILL users in kernel. For example, almost > every force_sig(SIGKILL) is wrong. force_sig() is not safe, it assumes > that the task has the valid ->sighand, and in general it should be used > only for synchronous signals. send_sig(SIGKILL, p, 1) or > send_xxx(SEND_SIG_FORCED/SEND_SIG_PRIV) is not right too but this is not > immediately obvious. > > The only way to correctly send SIGKILL is send_sig_info(SEND_SIG_NOINFO) > but we do not want to use this directly, because we can optimize this > case later. For example, zap_pid_ns_processes() allocates sigqueue for > each process in namespace, this is unneeded. > > Introduce the trivial send_sigkill() helper on top of send_sig_info() > and change zap_pid_ns_processes() as an example. > > Note: we need more cleanups here, this is only the first change. > > Signed-off-by: Oleg Nesterov Great. Reviewed-by: KOSAKI Motohiro -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/