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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 9DF8FC4CEC4 for ; Mon, 23 Sep 2019 16:18:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 7097620820 for ; Mon, 23 Sep 2019 16:18:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="A1x8ici4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7097620820 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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=OHhfjxB6XR940IDXf0fhoF/KHHBsO60HJd7IKbmoMT8=; b=A1x8ici4u3gHc1 X+BjWxco9+SKMEAo6k/y7CPWmskMIOLSpym/Qg/kSqtfzq3wuZPudulIpIISDJ84XIuFgq7RkLc7M AoRrofmvFe7WjTcYFosqJ0InmCMhHagdKKxEPmQTP5yw0MbxXWM/7tPySy58W2aimzJrbJb8sHwLe ngjD6J4tQdpvAvm1RXRlV1/eOX7chWgIARIX2mGpdcdnCLykGmwtk14f3i/NkzuZKPO8FTw3zpxEi 6nK5wzd+F9EoHhimbP0yXeasO7M2aPQAlJ3xTvyAXaBAVuJNRf/ZO/UbZIVk13FGqLQiOJh/cD86T Apps6suxg2RUI8+Qqr6g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCR2n-00075y-La; Mon, 23 Sep 2019 16:18:33 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCR2k-00075Y-QN for linux-arm-kernel@lists.infradead.org; Mon, 23 Sep 2019 16:18:32 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E50011000; Mon, 23 Sep 2019 09:18:29 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 404EF3F67D; Mon, 23 Sep 2019 09:18:27 -0700 (PDT) Date: Mon, 23 Sep 2019 17:18:25 +0100 From: Catalin Marinas To: Jia He Subject: Re: [PATCH v8 2/3] arm64: mm: implement arch_faults_on_old_pte() on arm64 Message-ID: <20190923161824.GD10192@arrakis.emea.arm.com> References: <20190921135054.142360-1-justin.he@arm.com> <20190921135054.142360-3-justin.he@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190921135054.142360-3-justin.he@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190923_091830_894824_72B3F131 X-CRM114-Status: GOOD ( 14.48 ) 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: Mark Rutland , Kaly Xin , Ralph Campbell , Andrew Morton , Suzuki Poulose , Marc Zyngier , Anshuman Khandual , linux-kernel@vger.kernel.org, Matthew Wilcox , linux-mm@kvack.org, =?iso-8859-1?B?Suly9G1l?= Glisse , James Morse , linux-arm-kernel@lists.infradead.org, Punit Agrawal , hejianet@gmail.com, Thomas Gleixner , nd@arm.com, Will Deacon , Alex Van Brunt , "Kirill A. Shutemov" , Robin Murphy Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Sep 21, 2019 at 09:50:53PM +0800, Jia He wrote: > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index e09760ece844..4a9939615e41 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -868,6 +868,18 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, > #define phys_to_ttbr(addr) (addr) > #endif > > +/* > + * On arm64 without hardware Access Flag, copying fromuser will fail because ^^^^^^^^ from user > + * the pte is old and cannot be marked young. So we always end up with zeroed > + * page after fork() + CoW for pfn mappings. we don't always have a ^^ We > + * hardware-managed access flag on arm64. > + */ > +static inline bool arch_faults_on_old_pte(void) > +{ > + return !cpu_has_hw_af(); I saw an early incarnation of your patch having a WARN_ON(preemptible()). I think we need this back just in case this function will be used elsewhere in the future. > +} > +#define arch_faults_on_old_pte arch_faults_on_old_pte Otherwise, Reviewed-by: Catalin Marinas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel