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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EEEF5C43461 for ; Wed, 16 Sep 2020 00:52:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7397620770 for ; Wed, 16 Sep 2020 00:52:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="EqW4ku7Y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726166AbgIOLdD (ORCPT ); Tue, 15 Sep 2020 07:33:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726135AbgIOL10 (ORCPT ); Tue, 15 Sep 2020 07:27:26 -0400 Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB6EAC06174A; Tue, 15 Sep 2020 04:26:39 -0700 (PDT) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4BrLXQ46X3z9sTN; Tue, 15 Sep 2020 21:26:30 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1600169192; bh=4esK02AyElAnyDXkxcmOZ58SrlxD5sLeYfaYLnFksAA=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=EqW4ku7Y8V1CrYGyOReTmatCQO246pQi3XD9hK8QImXa+8kAvrroYZZVLIhB5Cv/L 1HEJZtQS+acKXCy5mMNetAonLI2gIKpEbZxxPKtbRyxAhp7DbXfXGjBEQew0/9IUzn uRXbt4CCQ1FGVyJHUik+SPO4pM7Ori2zZ2q8Sd+rd7hSHtcrPmjcbc39dwb8ouGs30 Ogk0REO3vpcreFt7pS/TdkFGqXscY4gN+KJ+bOxq48bkRgo6e0daxPDJKsbboli0bK vt48IMrpUsOzMpDaqIlp3QryBj7HBTRa4U3hJ9O+w+fwBRbfp40WWPlE48hxMPs7KN n614Pr2VN9Jeg== From: Michael Ellerman To: Nicholas Piggin , peterz@infradead.org Cc: Jens Axboe , linux-arch@vger.kernel.org, "linux-mm \@ kvack . org" , "Aneesh Kumar K . V" , linux-kernel@vger.kernel.org, Andy Lutomirski , Dave Hansen , sparclinux@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S . Miller" Subject: Re: [PATCH v2 1/4] mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race In-Reply-To: <1600137586.nypnz3sbcl.astroid@bobo.none> References: <20200914045219.3736466-1-npiggin@gmail.com> <20200914045219.3736466-2-npiggin@gmail.com> <20200914105617.GP1362448@hirez.programming.kicks-ass.net> <1600137586.nypnz3sbcl.astroid@bobo.none> Date: Tue, 15 Sep 2020 21:26:29 +1000 Message-ID: <87lfhbp9ga.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nicholas Piggin writes: > Excerpts from peterz@infradead.org's message of September 14, 2020 8:56 pm: >> On Mon, Sep 14, 2020 at 02:52:16PM +1000, Nicholas Piggin wrote: >>> Reading and modifying current->mm and current->active_mm and switching >>> mm should be done with irqs off, to prevent races seeing an intermediate >>> state. ... >>> >>> Signed-off-by: Nicholas Piggin >> >> Acked-by: Peter Zijlstra (Intel) >> >> I'm thinking we want this selected on x86 as well. Andy? > > Thanks for the ack. The plan was to take it through the powerpc tree, > but if you'd want x86 to select it, maybe a topic branch? Although > Michael will be away during the next merge window so I don't want to > get too fancy. Would you mind doing it in a follow up merge after > powerpc, being that it's (I think) a small change? Or get akpm to take the series, including the x86 change. cheers