From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759873Ab3B1O6z (ORCPT ); Thu, 28 Feb 2013 09:58:55 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42462 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932831Ab3B1Oub (ORCPT ); Thu, 28 Feb 2013 09:50:31 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Satoru Takeuchi , Matt Fleming , "H. Peter Anvin" , Luis Henriques Subject: [PATCH 112/139] x86, efi: Make "noefi" really disable EFI runtime serivces Date: Thu, 28 Feb 2013 14:44:22 +0000 Message-Id: <1362062689-2567-113-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> References: <1362062689-2567-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Matt Fleming commit fb834c7acc5e140cf4f9e86da93a66de8c0514da upstream. commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to its documentation and disable EFI runtime services to prevent the bricking bug described in commit e0094244e41c ("samsung-laptop: Disable on EFI hardware"). However, it's not possible to clear EFI_RUNTIME_SERVICES from an early param function because EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param(). This resulted in "noefi" effectively becoming a no-op and no longer providing users with a way to disable EFI, which is bad for those users that have buggy machines. Reported-by: Walt Nelson Jr Cc: Satoru Takeuchi Signed-off-by: Matt Fleming Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin Signed-off-by: Luis Henriques --- arch/x86/platform/efi/efi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 3705bb0..1e40637 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -84,9 +84,10 @@ int efi_enabled(int facility) } EXPORT_SYMBOL(efi_enabled); +static bool disable_runtime = false; static int __init setup_noefi(char *arg) { - clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility); + disable_runtime = true; return 0; } early_param("noefi", setup_noefi); @@ -733,7 +734,7 @@ void __init efi_init(void) if (!efi_is_native()) pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); else { - if (efi_runtime_init()) + if (disable_runtime || efi_runtime_init()) return; set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility); } -- 1.8.1.2