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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 600B7C49ED7 for ; Fri, 20 Sep 2019 02:22:00 +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 3426C21924 for ; Fri, 20 Sep 2019 02:22:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LDABpUHE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3426C21924 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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=cgAgt+SFF2kB/fQYdeWJuXkYZcq/TjbABA8+sIB6HdI=; b=LDA BpUHEh8Wm0ioGRSjNMJu90S1nll9Hj+SO0165iDeN7OFh6UwRtm/LIcxpxrsnQJ5C0dDKW0o6hma5 1i9JsxF0Ie35fFjDh1t/gEJTJuAZPTL100N9M/20F4ujB4xTJp0Z/AhUTLxYy3Xvr0vIH3INmRvjs YJi44YX0YQSj2qzFtjJFxqLfAIMMSg1YbgDXjp1sejU9xVLB8SC5G2zYLkJ0Egv2Mx1iavtwhwnyZ W7eMHYoSJm2wky6Bh7ODsM08+155dEg/+pPbQsWXUmbVlTf2HBXijGemFNeoGw8pYkSCY2gmigjP1 aRIxLrmLvleedMFXL4//1NrOetn9lhQ==; 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 1iB8YU-0002Nw-Mq; Fri, 20 Sep 2019 02:21:54 +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 1iB8YP-0002Mx-Ka for linux-arm-kernel@lists.infradead.org; Fri, 20 Sep 2019 02:21:51 +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 AAF3C337; Thu, 19 Sep 2019 19:21:45 -0700 (PDT) Received: from localhost.localdomain (entos-thunderx2-02.shanghai.arm.com [10.169.40.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2F5563F67D; Thu, 19 Sep 2019 19:21:41 -0700 (PDT) From: Jia He To: Catalin Marinas , Will Deacon , Mark Rutland , James Morse , Marc Zyngier , Matthew Wilcox , "Kirill A. Shutemov" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Suzuki Poulose Subject: [PATCH v6 0/3] fix double page fault on arm64 Date: Fri, 20 Sep 2019 10:21:29 +0800 Message-Id: <20190920022132.149467-1-justin.he@arm.com> X-Mailer: git-send-email 2.17.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190919_192149_726132_379C9B14 X-CRM114-Status: UNSURE ( 8.95 ) X-CRM114-Notice: Please train this message. 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: Ralph Campbell , Jia He , Andrew Morton , Anshuman Khandual , Jun Yao , Kaly Xin , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Punit Agrawal , hejianet@gmail.com, Thomas Gleixner , Robin Murphy , Alex Van Brunt MIME-Version: 1.0 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 When we tested pmdk unit test vmmalloc_fork TEST1 in arm64 guest, there will be a double page fault in __copy_from_user_inatomic of cow_user_page. As told by Catalin: "On arm64 without hardware Access Flag, copying from user will fail because 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 hardware-managed access flag on arm64." Changes v6: fix error case of returning with spinlock taken (Catalin) move kmap_atomic to avoid handling kunmap_atomic v5: handle the case correctly when !pte_same fix kbuild test failed v4: introduce cpu_has_hw_af (Suzuki) bail out if !pte_same (Kirill) v3: add vmf->ptl lock/unlock (Kirill A. Shutemov) add arch_faults_on_old_pte (Matthew, Catalin) v2: remove FAULT_FLAG_WRITE when setting pte access flag (Catalin) Jia He (3): arm64: cpufeature: introduce helper cpu_has_hw_af() arm64: mm: implement arch_faults_on_old_pte() on arm64 mm: fix double page fault on arm64 if PTE_AF is cleared arch/arm64/include/asm/cpufeature.h | 10 +++++ arch/arm64/include/asm/pgtable.h | 12 ++++++ mm/memory.c | 65 ++++++++++++++++++++++++++--- 3 files changed, 81 insertions(+), 6 deletions(-) -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel