From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757394Ab1ERQ6a (ORCPT ); Wed, 18 May 2011 12:58:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25497 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757252Ab1ERQ63 (ORCPT ); Wed, 18 May 2011 12:58:29 -0400 Date: Wed, 18 May 2011 18:57:11 +0200 From: Oleg Nesterov To: Tejun Heo Cc: jan.kratochvil@redhat.com, vda.linux@googlemail.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, indan@nul.nu, bdonlan@gmail.com Subject: Re: [PATCH 02/10] job control: introduce JOBCTL_TRAP_STOP and use it for group stop trap Message-ID: <20110518165711.GA29279@redhat.com> References: <1305569849-10448-1-git-send-email-tj@kernel.org> <1305569849-10448-3-git-send-email-tj@kernel.org> <20110518164814.GA28848@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110518164814.GA28848@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/18, Oleg Nesterov wrote: > > So far I can't really understand why do we have both JOBCTL_TRAP_STOP and > and JOBCTL_TRAPPING... Please ignore, I didn't read other patches yet. OK, SEIZE sets JOBCTL_TRAP_STOP. > Hmm. And afaics there is a bug in do_signal_stop(), after > "[PATCH 6/9] job control: make task_clear_jobctl_pending() clear TRAPPING automatically" > ->jobctl &= ~JOBCTL_STOP_SIGMASK is no longer safe. We can clear _TRAPPING > without wakeup. And this also affects ptrace_attach(PTRACE_SEIZE), TRAP_STOP is cleared as well. Oleg.