From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965018AbbLBSBI (ORCPT ); Wed, 2 Dec 2015 13:01:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:43257 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933010AbbLBRAo (ORCPT ); Wed, 2 Dec 2015 12:00:44 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Krzysztof Mazur , Andy Lutomirski , Borislav Petkov , Laszlo Ersek , Matt Fleming , Paolo Bonzini , Thomas Gleixner , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 002/164] x86/setup: Fix low identity map for >= 2GB kernel range Date: Wed, 2 Dec 2015 08:57:33 -0800 Message-Id: <1449075615-20754-3-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1449075615-20754-1-git-send-email-kamal@canonical.com> References: <1449075615-20754-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Krzysztof Mazur commit 68accac392d859d24adcf1be3a90e41f978bd54c upstream. The commit f5f3497cad8c extended the low identity mapping. However, if the kernel uses more than 2 GB (VMSPLIT_2G_OPT or VMSPLIT_1G memory split), the normal memory mapping is overwritten by the low identity mapping causing a crash. To avoid overwritting, limit the low identity map to cover only memory before kernel range (PAGE_OFFSET). Fixes: f5f3497cad8c "x86/setup: Extend low identity map to cover whole kernel range Signed-off-by: Krzysztof Mazur Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Laszlo Ersek Cc: Matt Fleming Cc: Paolo Bonzini Link: http://lkml.kernel.org/r/1446815916-22105-1-git-send-email-krzysiek@podlesie.net Signed-off-by: Thomas Gleixner Signed-off-by: Kamal Mostafa --- arch/x86/kernel/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 5f660ca..51a4b6b 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1195,7 +1195,7 @@ void __init setup_arch(char **cmdline_p) */ clone_pgd_range(initial_page_table, swapper_pg_dir + KERNEL_PGD_BOUNDARY, - KERNEL_PGD_PTRS); + min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); #endif tboot_probe(); -- 1.9.1