From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932762AbaIOWPA (ORCPT ); Mon, 15 Sep 2014 18:15:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50879 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932732AbaIOWOw (ORCPT ); Mon, 15 Sep 2014 18:14:52 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "H. Peter Anvin" , Matt Fleming , Kamal Mostafa Subject: [PATCH 3.13 162/187] x86/efi: Enforce CONFIG_RELOCATABLE for EFI boot stub Date: Mon, 15 Sep 2014 15:09:32 -0700 Message-Id: <1410818997-9432-163-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1410818997-9432-1-git-send-email-kamal@canonical.com> References: <1410818997-9432-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Fleming commit 7b2a583afb4ab894f78bc0f8bd136e96b6499a7e upstream. Without CONFIG_RELOCATABLE the early boot code will decompress the kernel to LOAD_PHYSICAL_ADDR. While this may have been fine in the BIOS days, that isn't going to fly with UEFI since parts of the firmware code/data may be located at LOAD_PHYSICAL_ADDR. Straying outside of the bounds of the regions we've explicitly requested from the firmware will cause all sorts of trouble. Bruno reports that his machine resets while trying to decompress the kernel image. We already go to great pains to ensure the kernel is loaded into a suitably aligned buffer, it's just that the address isn't necessarily LOAD_PHYSICAL_ADDR, because we can't guarantee that address isn't in-use by the firmware. Explicitly enforce CONFIG_RELOCATABLE for the EFI boot stub, so that we can load the kernel at any address with the correct alignment. Reported-by: Bruno Prémont Tested-by: Bruno Prémont Cc: H. Peter Anvin Signed-off-by: Matt Fleming Signed-off-by: Kamal Mostafa --- arch/x86/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 08fa7df..03e74b3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1613,6 +1613,7 @@ config EFI config EFI_STUB bool "EFI stub support" depends on EFI + select RELOCATABLE ---help--- This kernel feature allows a bzImage to be loaded directly by EFI firmware without the use of a bootloader. -- 1.9.1