From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Krzysztof Mazur , Andy Lutomirski , Borislav Petkov , Laszlo Ersek , Matt Fleming , Paolo Bonzini , Thomas Gleixner Subject: [PATCH 3.14 18/37] x86/setup: Fix low identity map for >= 2GB kernel range Date: Mon, 7 Dec 2015 09:26:30 -0500 Message-Id: <20151207141744.197741383@linuxfoundation.org> In-Reply-To: <20151207141743.221453847@linuxfoundation.org> References: <20151207141743.221453847@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.14-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: Greg Kroah-Hartman --- arch/x86/kernel/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1185,7 +1185,7 @@ 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();