From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753452AbaBGMGB (ORCPT ); Fri, 7 Feb 2014 07:06:01 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42397 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752988AbaBGLwS (ORCPT ); Fri, 7 Feb 2014 06:52:18 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Andrey Vagin , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Pavel Emelyanov , Borislav Petkov , Wen Congyang , Andrew Morton , Linus Torvalds , Luis Henriques Subject: [PATCH 3.11 197/233] mm: don't lose the SOFT_DIRTY flag on mprotect Date: Fri, 7 Feb 2014 11:46:56 +0000 Message-Id: <1391773652-25214-198-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> References: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrey Vagin commit 24f91eba18bbfdb27e71a1aae5b3a61b67fcd091 upstream. The SOFT_DIRTY bit shows that the content of memory was changed after a defined point in the past. mprotect() doesn't change the content of memory, so it must not change the SOFT_DIRTY bit. This bug causes a malfunction: on the first iteration all pages are dumped. On other iterations only pages with the SOFT_DIRTY bit are dumped. So if the SOFT_DIRTY bit is cleared from a page by mistake, the page is not dumped and its content will be restored incorrectly. This patch does nothing with _PAGE_SWP_SOFT_DIRTY, becase pte_modify() is called only for present pages. Fixes commit 0f8975ec4db2 ("mm: soft-dirty bits for user memory changes tracking"). Signed-off-by: Andrey Vagin Acked-by: Cyrill Gorcunov Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Pavel Emelyanov Cc: Borislav Petkov Cc: Wen Congyang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Luis Henriques --- arch/x86/include/asm/pgtable_types.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index f4843e0..4e700b1 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -118,7 +118,8 @@ /* Set of bits not changed in pte_modify */ #define _PAGE_CHG_MASK (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT | \ - _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY) + _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \ + _PAGE_SOFT_DIRTY) #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE) #define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) -- 1.8.3.2