From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753405AbdKWVtL (ORCPT ); Thu, 23 Nov 2017 16:49:11 -0500 Received: from one.firstfloor.org ([193.170.194.197]:35274 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753046AbdKWVtJ (ORCPT ); Thu, 23 Nov 2017 16:49:09 -0500 Date: Thu, 23 Nov 2017 13:49:07 -0800 From: Andi Kleen To: Mathieu Desnoyers Cc: Peter Zijlstra , Andi Kleen , "Paul E. McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson , linux-kernel , linux-api , Paul Turner , Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andrew Hunter , Chris Lameter , Ben Maurer , rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon , Michael Kerrisk Subject: Re: [RFC PATCH for 4.15 v12 00/22] Restartable sequences and CPU op vector Message-ID: <20171123214907.GO2482@two.firstfloor.org> References: <20171121141900.18471-1-mathieu.desnoyers@efficios.com> <20171121172144.GL2482@two.firstfloor.org> <740195164.19702.1511301908907.JavaMail.zimbra@efficios.com> <20171122193219.GI3165@worktop.lehotels.local> <2130360737.21248.1511471602798.JavaMail.zimbra@efficios.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2130360737.21248.1511471602798.JavaMail.zimbra@efficios.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Also, turning both line-level and instruction-level single-stepping into > infinite loops looks pretty much like a new kernel facility that breaks > user-space. It's a no-go from my point of view. You could fix it at the debugger level with suitable annotation. Just turn the whole rseq into an extended line, and make sure it is handled for instruction stepping too. -Andi From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [RFC PATCH for 4.15 v12 00/22] Restartable sequences and CPU op vector Date: Thu, 23 Nov 2017 13:49:07 -0800 Message-ID: <20171123214907.GO2482@two.firstfloor.org> References: <20171121141900.18471-1-mathieu.desnoyers@efficios.com> <20171121172144.GL2482@two.firstfloor.org> <740195164.19702.1511301908907.JavaMail.zimbra@efficios.com> <20171122193219.GI3165@worktop.lehotels.local> <2130360737.21248.1511471602798.JavaMail.zimbra@efficios.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <2130360737.21248.1511471602798.JavaMail.zimbra@efficios.com> Sender: linux-kernel-owner@vger.kernel.org To: Mathieu Desnoyers Cc: Peter Zijlstra , Andi Kleen , "Paul E. McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson , linux-kernel , linux-api , Paul Turner , Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andrew Hunter , Chris Lameter , Ben Maurer , rostedt , Josh Triplett , Linus Torvalds , Catalin List-Id: linux-api@vger.kernel.org > Also, turning both line-level and instruction-level single-stepping into > infinite loops looks pretty much like a new kernel facility that breaks > user-space. It's a no-go from my point of view. You could fix it at the debugger level with suitable annotation. Just turn the whole rseq into an extended line, and make sure it is handled for instruction stepping too. -Andi