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 X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 537C4C433E5 for ; Thu, 23 Jul 2020 15:50:54 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C4A12071A for ; Thu, 23 Jul 2020 15:50:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TPcb5j3f" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C4A12071A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/0DWRorqB6rEM21trPYYbfJHcVzGSTQxjUKso9QzuRo=; b=TPcb5j3f9gKKBD31FHMuh3dMf L+EiG7uimu7fyXNM1hPa32TcmnkxYcrIidHkG87+XtmHnpGcIzGP/c78g6F7O1D8hBmnJwQ9d7Jbh 8YHNGIm+YjtMk+B0FRFGtauZERe+b0Jm4EWkxhavVvqiH86YnV9OUIAB4qqE5JPrqzSO9IjYsqPjT vRdsGeRDs2I/b3GXXSLOJQsUud7ZFY/iJU5UG9McTdy9mOVrljqp4+kOQWG5dCUk6cqKl17nMVOpk en4vRTngEYVLc1/blUifWP/lt5aYQginXfLBztPR0kJ+7PA9c9HeR5fB2QXE1Wam42qP2eAx7izC4 Qrqqb1Zvw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jydTV-00063T-D6; Thu, 23 Jul 2020 15:49:37 +0000 Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jydTT-00062q-17; Thu, 23 Jul 2020 15:49:35 +0000 Received: by worktop.programming.kicks-ass.net (Postfix, from userid 1000) id 5BD82983422; Thu, 23 Jul 2020 17:49:33 +0200 (CEST) Date: Thu, 23 Jul 2020 17:49:33 +0200 From: Peter Zijlstra To: Alex Belits Subject: Re: [PATCH v4 00/13] "Task_isolation" mode Message-ID: <20200723154933.GB709@worktop.programming.kicks-ass.net> References: <04be044c1bcd76b7438b7563edc35383417f12c8.camel@marvell.com> <87imeextf3.fsf@nanos.tec.linutronix.de> <831e023422aa0e4cb3da37ceef6fdcd5bc854682.camel@marvell.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <831e023422aa0e4cb3da37ceef6fdcd5bc854682.camel@marvell.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-arch@vger.kernel.org" , "catalin.marinas@arm.com" , Prasun Kapoor , "frederic@kernel.org" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "davem@davemloft.net" , "netdev@vger.kernel.org" , "linux-api@vger.kernel.org" , "tglx@linutronix.de" , "will@kernel.org" , "mingo@kernel.org" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jul 23, 2020 at 03:18:42PM +0000, Alex Belits wrote: > On Thu, 2020-07-23 at 15:17 +0200, Thomas Gleixner wrote: > > > > Without going into details of the individual patches, let me give you a > > high level view of this series: > > > > 1) Entry code handling: > > > > That's completely broken vs. the careful ordering and instrumentation > > protection of the entry code. You can't just slap stuff randomly > > into places which you think are safe w/o actually trying to understand > > why this code is ordered in the way it is. > > > > This clearly was never built and tested with any of the relevant > > debug options enabled. Both build and boot would have told you. > > This is intended to avoid a race condition when entry or exit from isolation > happens at the same time as an event that requires synchronization. The idea > is, it is possible to insulate the core from all events while it is running > isolated task in userspace, it will receive those calls normally after > breaking isolation and entering kernel, and it will synchronize itself on > kernel entry. 'What does noinstr mean? and why do we have it" -- don't dare touch the entry code until you can answer that. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel