From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752251AbeEOGyK (ORCPT ); Tue, 15 May 2018 02:54:10 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:52312 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751927AbeEOGyJ (ORCPT ); Tue, 15 May 2018 02:54:09 -0400 X-Google-Smtp-Source: AB8JxZrOpboGUrIVhUmUurHsRAnRHsIurThvveGkhw/bFTwB28YbkJPo4om7uPgyJYQmS0shlS6LiA== Date: Tue, 15 May 2018 08:54:05 +0200 From: Ingo Molnar To: hpa@zytor.com Cc: David Laight , "'Alexey Dobriyan'" , "tglx@linutronix.de" , "mingo@redhat.com" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" Subject: Re: [PATCH] x86: pad assembly functions with INT3 Message-ID: <20180515065405.GA31240@gmail.com> References: <20180507213755.GA32406@avx2> <20fb84fd5eef4c45b2d38d0290235d5d@AcuMS.aculab.com> <5c6762fe-5cbe-42ed-ac4e-a7144b8ef7ad@zytor.com> <83866d054b27419c9d9dd97d9c66c3de@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * hpa@zytor.com wrote: > > I guess it won't try to speculatively execute the 'pad' instructions - but you > > can never really tell! > > > > David > > The CPU doesn't speculate down past an unconditional control transfer. Doing so > would be idiotic. I think, when it comes to speculative execution, our general expectation that CPUs don't do idiotic things got somewhat weakened in the past year or so ... Thanks, Ingo