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[209.132.180.67]) by mx.google.com with ESMTP id d13si11898064ejj.317.2019.11.04.14.13.57; Mon, 04 Nov 2019 14:14:20 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=T3Xs3v+k; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390082AbfKDWJt (ORCPT + 99 others); Mon, 4 Nov 2019 17:09:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:42948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390464AbfKDWJr (ORCPT ); Mon, 4 Nov 2019 17:09:47 -0500 Received: from localhost (6.204-14-84.ripe.coltfrance.com [84.14.204.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 26105205C9; Mon, 4 Nov 2019 22:09:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572905386; bh=lQJCxjQE5u8YIzXEATjD4sjbt1UHBwao+yZ85ZGUxlI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T3Xs3v+kGv6FcJ/1GsmD01MRkXq4TvPHa+5Famp0ckNv6p9WMzhgdtql6n3NyjI3b mgfp1av97IfRIyrpU6WvcpG4NPHptjDbz0q9iHt6/I1YUIzI3LOdTUNSPwOGSHkocg /3aZstF/ygcMaN7yXhs2geQ1BZvmP9FrZZcvcTo8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Will Deacon , Catalin Marinas Subject: [PATCH 5.3 127/163] arm64: Ensure VM_WRITE|VM_SHARED ptes are clean by default Date: Mon, 4 Nov 2019 22:45:17 +0100 Message-Id: <20191104212149.465507089@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191104212140.046021995@linuxfoundation.org> References: <20191104212140.046021995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Catalin Marinas commit aa57157be69fb599bd4c38a4b75c5aad74a60ec0 upstream. Shared and writable mappings (__S.1.) should be clean (!dirty) initially and made dirty on a subsequent write either through the hardware DBM (dirty bit management) mechanism or through a write page fault. A clean pte for the arm64 kernel is one that has PTE_RDONLY set and PTE_DIRTY clear. The PAGE_SHARED{,_EXEC} attributes have PTE_WRITE set (PTE_DBM) and PTE_DIRTY clear. Prior to commit 73e86cb03cf2 ("arm64: Move PTE_RDONLY bit handling out of set_pte_at()"), it was the responsibility of set_pte_at() to set the PTE_RDONLY bit and mark the pte clean if the software PTE_DIRTY bit was not set. However, the above commit removed the pte_sw_dirty() check and the subsequent setting of PTE_RDONLY in set_pte_at() while leaving the PAGE_SHARED{,_EXEC} definitions unchanged. The result is that shared+writable mappings are now dirty by default Fix the above by explicitly setting PTE_RDONLY in PAGE_SHARED{,_EXEC}. In addition, remove the superfluous PTE_DIRTY bit from the kernel PROT_* attributes. Fixes: 73e86cb03cf2 ("arm64: Move PTE_RDONLY bit handling out of set_pte_at()") Cc: # 4.14.x- Cc: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/pgtable-prot.h | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -32,11 +32,11 @@ #define PROT_DEFAULT (_PROT_DEFAULT | PTE_MAYBE_NG) #define PROT_SECT_DEFAULT (_PROT_SECT_DEFAULT | PMD_MAYBE_NG) -#define PROT_DEVICE_nGnRnE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRnE)) -#define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRE)) -#define PROT_NORMAL_NC (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_NC)) -#define PROT_NORMAL_WT (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_WT)) -#define PROT_NORMAL (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL)) +#define PROT_DEVICE_nGnRnE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRnE)) +#define PROT_DEVICE_nGnRE (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRE)) +#define PROT_NORMAL_NC (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_NC)) +#define PROT_NORMAL_WT (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_WT)) +#define PROT_NORMAL (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL)) #define PROT_SECT_DEVICE_nGnRE (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE)) #define PROT_SECT_NORMAL (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL)) @@ -80,8 +80,9 @@ #define PAGE_S2_DEVICE __pgprot(_PROT_DEFAULT | PAGE_S2_MEMATTR(DEVICE_nGnRE) | PTE_S2_RDONLY | PAGE_S2_XN) #define PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN) -#define PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE) -#define PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE) +/* shared+writable pages are clean by default, hence PTE_RDONLY|PTE_WRITE */ +#define PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE) +#define PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_WRITE) #define PAGE_READONLY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_READONLY_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN) #define PAGE_EXECONLY __pgprot(_PAGE_DEFAULT | PTE_RDONLY | PTE_NG | PTE_PXN)