From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B39A1C433FE for ; Wed, 13 Apr 2022 19:21:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238288AbiDMTXs (ORCPT ); Wed, 13 Apr 2022 15:23:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238461AbiDMTXh (ORCPT ); Wed, 13 Apr 2022 15:23:37 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0271483BD; Wed, 13 Apr 2022 12:21:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=5200STCdSkk0cXg3Unfn6dqxNXzM2r04BJOn85iTJrM=; b=K6NCmdSuMj5cYgpO14HzXFxN1a qbuS/mZIi32FSsurz4EouHfUQoTJKLyI21byCBW6q+5UQBRlXvWApYkd713NTs1ZYw3NkeorFadXp nBttLHpjF1rHJ9G0PfurfmLfBkU+mfHwixrFuk64BDs0+bz5y7HOqoK8OPZgqYL6ujGWNSsIJI2v2 VBE6aP07fPcD1mp+JUh2Z6MTd/5vi14MUcPnPdwjhBMFXPArdtvAuWt8HpTbLNc7i53BAGN5M9rjd 0ml5bdRzBFk28+VV7FA5Lt3JZkPZzDtdxTz88tco+7AHYx9m/WcSC5aH7UilkzoFrBZB+kF02bwlo Klfs/Esg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1neiXv-00EViw-64; Wed, 13 Apr 2022 19:20:55 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id B6C0598623C; Wed, 13 Apr 2022 21:20:53 +0200 (CEST) Date: Wed, 13 Apr 2022 21:20:53 +0200 From: Peter Zijlstra To: Oleg Nesterov Cc: rjw@rjwysocki.net, mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, ebiederm@xmission.com, bigeasy@linutronix.de, Will Deacon , linux-kernel@vger.kernel.org, tj@kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 2/5] sched,ptrace: Fix ptrace_check_attach() vs PREEMPT_RT Message-ID: <20220413192053.GY2731@worktop.programming.kicks-ass.net> References: <20220412114421.691372568@infradead.org> <20220412114853.842942162@infradead.org> <20220413132451.GA27281@redhat.com> <20220413185704.GA30360@redhat.com> <20220413185909.GB30360@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220413185909.GB30360@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 13, 2022 at 08:59:10PM +0200, Oleg Nesterov wrote: > + // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! > + // wrong, needs siglock > + current->jobctl &= ~JOBCTL_TRACED_XXX; > + wake_up_bit(¤t->jobctl, ~JOBCTL_TRACED_XXX_BIT); __wake_up_common_lock() spin_lock_irqsave() current_save_and_set_rtlock_wait_state(); > + if (wait_on_bit(&task->jobctl, JOBCTL_TRACED_XXX_BIT, TASK_KILLABLE)) > + return -EINTR; > + // now that the tracee cleared JOBCTL_TRACED_XXX_BIT > + // wait_task_inactive() should succeed or fail "really soon". > + if (!wait_task_inactive(child, __TASK_TRACED)) > + return ret; *whoopsie* ? > preempt_enable_no_resched(); > freezable_schedule(); > cgroup_leave_frozen(true);