Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751664AbaJPIBV (ORCPT ); Thu, 16 Oct 2014 04:01:21 -0400 Received: from casper.infradead.org ([85.118.1.10]:50200 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751269AbaJPIBU (ORCPT ); Thu, 16 Oct 2014 04:01:20 -0400 Date: Thu, 16 Oct 2014 10:01:06 +0200 From: Peter Zijlstra To: Oleg Nesterov Cc: Kirill Tkhai , linux-kernel@vger.kernel.org, Ingo Molnar , Vladimir Davydov , Kirill Tkhai Subject: Re: [PATCH RFC] sched: Revert delayed_put_task_struct() and fix use after free Message-ID: <20141016080106.GD7369@worktop.fdxtended.com> References: <1413376300.24793.55.camel@tkhai> <20141015150641.GA2755@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141015150641.GA2755@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 On Wed, Oct 15, 2014 at 05:06:41PM +0200, Oleg Nesterov wrote: > > At least the code like > > rcu_read_lock(); > get_task_struct(foreign_rq->curr); > rcu_read_unlock(); > > is certainly wrong. And _probably_ the problem should be fixed here. Perhaps > we can add try_to_get_task_struct() which does atomic_inc_not_zero() ... There is an rcu_read_lock() around it through task_numa_compare(). -- 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/