From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DFF5C43140 for ; Fri, 6 Sep 2019 09:52:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3990B206CD for ; Fri, 6 Sep 2019 09:52:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392989AbfIFJwL (ORCPT ); Fri, 6 Sep 2019 05:52:11 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:46795 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392975AbfIFJwK (ORCPT ); Fri, 6 Sep 2019 05:52:10 -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 1i6AuS-000557-PG; Fri, 06 Sep 2019 11:52:04 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 4B09D1C0DE8; Fri, 6 Sep 2019 11:52:04 +0200 (CEST) Date: Fri, 06 Sep 2019 09:52:04 -0000 From: "tip-bot2 for Jiri Slaby" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/asm] x86/asm/suspend: Get rid of bogus_64_magic Cc: Jiri Slaby , Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Len Brown , linux-pm@vger.kernel.org, Pavel Machek , "Rafael J. Wysocki" , Thomas Gleixner , "x86-ml" , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org In-Reply-To: <20190906075550.23435-1-jslaby@suse.cz> References: <20190906075550.23435-1-jslaby@suse.cz> MIME-Version: 1.0 Message-ID: <156776352423.24167.12782521075233555186.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/asm branch of tip: Commit-ID: 559ceeed62a5121783a8955c63aeb18aaa0ef224 Gitweb: https://git.kernel.org/tip/559ceeed62a5121783a8955c63aeb18aaa0ef224 Author: Jiri Slaby AuthorDate: Fri, 06 Sep 2019 09:55:49 +02:00 Committer: Borislav Petkov CommitterDate: Fri, 06 Sep 2019 10:34:15 +02:00 x86/asm/suspend: Get rid of bogus_64_magic bogus_64_magic is only a dead-end loop. There is no need for an out-of-order function (and unannotated local label), so just handle it in-place and also store 0xbad-m-a-g-i-c to %rcx beforehand, in case someone is inspecting registers. Here a qemu+gdb example: Remote debugging using localhost:1235 wakeup_long64 () at arch/x86/kernel/acpi/wakeup_64.S:26 26 jmp 1b (gdb) info registers rax 0x123456789abcdef0 1311768467463790320 rbx 0x0 0 rcx 0xbad6d61676963 3286910041024867 ^^^^^^^^^^^^^^^ [ bp: Add the gdb example. ] Signed-off-by: Jiri Slaby Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Len Brown Cc: linux-pm@vger.kernel.org Cc: Pavel Machek Cc: "Rafael J. Wysocki" Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20190906075550.23435-1-jslaby@suse.cz --- arch/x86/kernel/acpi/wakeup_64.S | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S index b0715c3..7f9ade1 100644 --- a/arch/x86/kernel/acpi/wakeup_64.S +++ b/arch/x86/kernel/acpi/wakeup_64.S @@ -18,8 +18,13 @@ ENTRY(wakeup_long64) movq saved_magic, %rax movq $0x123456789abcdef0, %rdx cmpq %rdx, %rax - jne bogus_64_magic + je 2f + /* stop here on a saved_magic mismatch */ + movq $0xbad6d61676963, %rcx +1: + jmp 1b +2: movw $__KERNEL_DS, %ax movw %ax, %ss movw %ax, %ds @@ -37,9 +42,6 @@ ENTRY(wakeup_long64) jmp *%rax ENDPROC(wakeup_long64) -bogus_64_magic: - jmp bogus_64_magic - ENTRY(do_suspend_lowlevel) FRAME_BEGIN subq $8, %rsp