From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755998Ab2BAInP (ORCPT ); Wed, 1 Feb 2012 03:43:15 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:43127 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752673Ab2BAInO (ORCPT ); Wed, 1 Feb 2012 03:43:14 -0500 Date: Wed, 1 Feb 2012 09:05:40 +0100 From: Ingo Molnar To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Andrew Morton , Jason Baron , "H. Peter Anvin" , Frederic Weisbecker Subject: Re: [PATCH 0/5 v2] [GIT PULL] x86/jump label: Paranoid checks and 2 or 5 byte nops Message-ID: <20120201080539.GA11770@elte.hu> References: <20120128160925.275163704@goodmis.org> <20120130144857.GA22013@elte.hu> <1327936060.22710.165.camel@gandalf.stny.rr.com> <20120131194813.GA12074@elte.hu> <1328072925.5882.57.camel@gandalf.stny.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1328072925.5882.57.camel@gandalf.stny.rr.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > On Tue, 2012-01-31 at 20:48 +0100, Ingo Molnar wrote: > > > Attached. (you need to run it through make oldconfig and use the > > defaults.) > > Hmm, I'm not able to reproduce it. > > Could you apply this patch and run it again. I'm interested in what was > at the location when it tried to do the conversion. > > Thanks! > > -- Steve > > diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c > index 6173ca6..da12264 100644 > --- a/arch/x86/kernel/jump_label.c > +++ b/arch/x86/kernel/jump_label.c > @@ -58,13 +58,17 @@ static void __jump_label_transform(struct jump_entry *entry, > size = JUMP_LABEL_NOP_SIZE; > code.jump = 0xe9; > code.offset = entry->target - (entry->code + size); > - } else > + } else { > + unsigned char *ins = ip; > /* > * The location is not a nop that we were expecting, > * something went wrong. Crash the box, as something could be > * corrupting the kernel. > */ > + printk("Unknown op at %pS (%02x:%02x:%02x:%02x:%02x)\n", > + ip, ins[0], ins[1], ins[2], ins[3], ins[4]); > BUG(); > + } It would be better to make this a regular commit, this kind of diagnostics obviously makes sense. That way i could pull in your updated branch for more testing. Thanks, Ingo