From patchwork Mon Oct 7 14:49:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: thermal-bot for Julien Panis X-Patchwork-Id: 11177635 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 253FA139A for ; Mon, 7 Oct 2019 14:51:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DDEF218AC for ; Mon, 7 Oct 2019 14:51:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727715AbfJGOvT (ORCPT ); Mon, 7 Oct 2019 10:51:19 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:44393 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728459AbfJGOte (ORCPT ); Mon, 7 Oct 2019 10:49:34 -0400 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iHUJx-0005pO-UU; Mon, 07 Oct 2019 16:49:10 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 72A151C032F; Mon, 7 Oct 2019 16:49:09 +0200 (CEST) Date: Mon, 07 Oct 2019 14:49:09 -0000 From: "tip-bot2 for Dave Young" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: efi/urgent] efi/x86: Do not clean dummy variable in kexec path Cc: Dave Young , Ard Biesheuvel , Matthew Garrett , Ben Dooks , Jarkko Sakkinen , Jerry Snitselaar , Linus Torvalds , Lukas Wunner , Lyude Paul , Octavian Purdila , Peter Jones , Peter Zijlstra , Scott Talbert , Thomas Gleixner , linux-efi@vger.kernel.org, linux-integrity@vger.kernel.org, Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org In-Reply-To: <20191002165904.8819-8-ard.biesheuvel@linaro.org> References: <20191002165904.8819-8-ard.biesheuvel@linaro.org> MIME-Version: 1.0 Message-ID: <157045974933.9978.15804393838159237805.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The following commit has been merged into the efi/urgent branch of tip: Commit-ID: 2ecb7402cfc7f22764e7bbc80790e66eadb20560 Gitweb: https://git.kernel.org/tip/2ecb7402cfc7f22764e7bbc80790e66eadb20560 Author: Dave Young AuthorDate: Wed, 02 Oct 2019 18:59:04 +02:00 Committer: Ingo Molnar CommitterDate: Mon, 07 Oct 2019 15:24:36 +02:00 efi/x86: Do not clean dummy variable in kexec path kexec reboot fails randomly in UEFI based KVM guest. The firmware just resets while calling efi_delete_dummy_variable(); Unfortunately I don't know how to debug the firmware, it is also possible a potential problem on real hardware as well although nobody reproduced it. The intention of the efi_delete_dummy_variable is to trigger garbage collection when entering virtual mode. But SetVirtualAddressMap can only run once for each physical reboot, thus kexec_enter_virtual_mode() is not necessarily a good place to clean a dummy object. Drop the efi_delete_dummy_variable so that kexec reboot can work. Signed-off-by: Dave Young Signed-off-by: Ard Biesheuvel Acked-by: Matthew Garrett Cc: Ben Dooks Cc: Jarkko Sakkinen Cc: Jerry Snitselaar Cc: Linus Torvalds Cc: Lukas Wunner Cc: Lyude Paul Cc: Octavian Purdila Cc: Peter Jones Cc: Peter Zijlstra Cc: Scott Talbert Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Cc: linux-integrity@vger.kernel.org Link: https://lkml.kernel.org/r/20191002165904.8819-8-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- arch/x86/platform/efi/efi.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index c202e1b..425e025 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -917,9 +917,6 @@ static void __init kexec_enter_virtual_mode(void) if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) runtime_code_page_mkexec(); - - /* clean DUMMY object */ - efi_delete_dummy_variable(); #endif }