Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756177AbcDNPbS (ORCPT ); Thu, 14 Apr 2016 11:31:18 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:53616 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754968AbcDNPbR (ORCPT ); Thu, 14 Apr 2016 11:31:17 -0400 Date: Thu, 14 Apr 2016 17:31:11 +0200 From: Peter Zijlstra To: Xunlei Pang Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Juri Lelli , Ingo Molnar , Steven Rostedt Subject: Re: [PATCH v3 5/6] sched/deadline/rtmutex: Fix unprotected PI access in enqueue_task_dl() Message-ID: <20160414153111.GC2975@worktop.cust.blueprintrf.com> References: <1460633827-345-1-git-send-email-xlpang@redhat.com> <1460633827-345-6-git-send-email-xlpang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1460633827-345-6-git-send-email-xlpang@redhat.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 278 Lines: 5 On Thu, Apr 14, 2016 at 07:37:06PM +0800, Xunlei Pang wrote: > We access @pi_task's data without any lock in enqueue_task_dl(), though > checked "dl_prio(pi_task->normal_prio)" condition, that's not enough. The proper fix is to ensure that pi_task is guaranteed to be blocked.