From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935899Ab3BTUgT (ORCPT ); Wed, 20 Feb 2013 15:36:19 -0500 Received: from arkanian.console-pimps.org ([212.110.184.194]:59552 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934126Ab3BTUgR (ORCPT ); Wed, 20 Feb 2013 15:36:17 -0500 From: Matt Fleming To: "H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, Matt Fleming , Satoru Takeuchi , Subject: [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces Date: Wed, 20 Feb 2013 20:36:12 +0000 Message-Id: <1361392572-25657-1-git-send-email-matt@console-pimps.org> X-Mailer: git-send-email 1.7.11.7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matt Fleming 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 Cc: H. Peter Anvin Cc: Signed-off-by: Matt Fleming --- 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 928bf83..e2cd38f 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -85,9 +85,10 @@ 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); @@ -734,7 +735,7 @@ 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); } -- 1.7.11.7