From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753945AbZLBKqT (ORCPT ); Wed, 2 Dec 2009 05:46:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753275AbZLBKqS (ORCPT ); Wed, 2 Dec 2009 05:46:18 -0500 Received: from hera.kernel.org ([140.211.167.34]:45044 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753005AbZLBKqR (ORCPT ); Wed, 2 Dec 2009 05:46:17 -0500 Date: Wed, 2 Dec 2009 10:45:50 GMT From: tip-bot for Jan Beulich Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, jbeulich@novell.com, JBeulich@novell.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, jbeulich@novell.com, JBeulich@novell.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <4B0FF8AA0200007800022703@vpn.id2.novell.com> References: <4B0FF8AA0200007800022703@vpn.id2.novell.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/alternatives: Check replacementlen <= instrlen at build time Message-ID: Git-Commit-ID: 01be50a308be466e122c3a8b3d535f1b673ecbd2 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 01be50a308be466e122c3a8b3d535f1b673ecbd2 Gitweb: http://git.kernel.org/tip/01be50a308be466e122c3a8b3d535f1b673ecbd2 Author: Jan Beulich AuthorDate: Fri, 27 Nov 2009 15:04:58 +0000 Committer: Ingo Molnar CommitDate: Wed, 2 Dec 2009 11:39:45 +0100 x86/alternatives: Check replacementlen <= instrlen at build time Having run into the run-(boot-)time check a couple of times lately, I finally took time to find a build-time check so that one doesn't need to analyze the register/stack dump and resolve this (through manual lookup in vmlinux) to the offending construct. The assembler will emit a message like "Error: value of too large for field of 1 bytes at ", which while not pointing out the source location still makes analysis quite a bit easier. Signed-off-by: Jan Beulich LKML-Reference: <4B0FF8AA0200007800022703@vpn.id2.novell.com> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/alternative.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index c240efc..69b74a7 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -84,6 +84,7 @@ static inline void alternatives_smp_switch(int smp) {} " .byte " __stringify(feature) "\n" /* feature bit */ \ " .byte 662b-661b\n" /* sourcelen */ \ " .byte 664f-663f\n" /* replacementlen */ \ + " .byte 0xff + (664f-663f) - (662b-661b)\n" /* rlen <= slen */ \ ".previous\n" \ ".section .altinstr_replacement, \"ax\"\n" \ "663:\n\t" newinstr "\n664:\n" /* replacement */ \