From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932143AbbLRMrk (ORCPT ); Fri, 18 Dec 2015 07:47:40 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33204 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753376AbbLRMko (ORCPT ); Fri, 18 Dec 2015 07:40:44 -0500 From: Josh Poimboeuf To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , Namhyung Kim , Bernd Petrovitsch , Chris J Arges , Andrew Morton , Jiri Slaby , Arnaldo Carvalho de Melo Subject: [PATCH v15 13/25] x86/reboot: Add ljmp instructions to stacktool whitelist Date: Fri, 18 Dec 2015 06:39:27 -0600 Message-Id: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org stacktool reports a false positive warning for the ljmp instruction in machine_real_restart(). Normally, ljmp isn't allowed in a function, but this is a special case where it's jumping into real mode. Add the jumps to a whitelist which tells stacktool to ignore them. Signed-off-by: Josh Poimboeuf --- arch/x86/kernel/reboot.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 02693dd..1ea1c5e 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -97,11 +98,13 @@ void __noreturn machine_real_restart(unsigned int type) /* Jump to the identity-mapped low memory code */ #ifdef CONFIG_X86_32 - asm volatile("jmpl *%0" : : + asm volatile(STACKTOOL_IGNORE_INSN + "jmpl *%0;" : : "rm" (real_mode_header->machine_real_restart_asm), "a" (type)); #else - asm volatile("ljmpl *%0" : : + asm volatile(STACKTOOL_IGNORE_INSN + "ljmpl *%0" : : "m" (real_mode_header->machine_real_restart_asm), "D" (type)); #endif -- 2.4.3