Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754702AbbLIKKI (ORCPT ); Wed, 9 Dec 2015 05:10:08 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:45309 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754539AbbLIJki (ORCPT ); Wed, 9 Dec 2015 04:40:38 -0500 From: Luis Henriques 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 , Luis Henriques Subject: [PATCH 3.16.y-ckt 068/126] x86/setup: Fix low identity map for >= 2GB kernel range Date: Wed, 9 Dec 2015 09:37:18 +0000 Message-Id: <1449653896-5236-69-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1449653896-5236-1-git-send-email-luis.henriques@canonical.com> References: <1449653896-5236-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1830 Lines: 46 3.16.7-ckt21 -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: Luis Henriques --- 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 56788204d85e..b1077b8ee7af 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1184,7 +1184,7 @@ 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(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/