Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756115Ab0AVSHI (ORCPT ); Fri, 22 Jan 2010 13:07:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755881Ab0AVSHH (ORCPT ); Fri, 22 Jan 2010 13:07:07 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:39599 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755443Ab0AVSHG (ORCPT ); Fri, 22 Jan 2010 13:07:06 -0500 Subject: Re: [RFC] [PATCH 0/7] UBP, XOL and Uprobes [ Summary of Comments and actions to be taken ] From: Peter Zijlstra To: Srikar Dronamraju Cc: Ingo Molnar , Ananth N Mavinakayanahalli , utrace-devel , Frederic Weisbecker , Masami Hiramatsu , Maneesh Soni , Jim Keniston , Avi Kivity , Pekka Enberg , Mel Gorman , "Paul E. McKenney" , LKML In-Reply-To: <20100122070232.GA2975@linux.vnet.ibm.com> References: <20100111122521.22050.3654.sendpatchset@srikar.in.ibm.com> <20100122070232.GA2975@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 22 Jan 2010 19:06:14 +0100 Message-ID: <1264183574.4283.1558.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1298 Lines: 30 On Fri, 2010-01-22 at 12:32 +0530, Srikar Dronamraju wrote: > 2. XOL vma vs Emulation vs Single Stepping Inline vs using Protection > Rings. > XOL VMA is an additional process address vma. This is > opposition to add an additional vma without user actually > requesting for the same. > > XOL vma and single stepping inline are the two architecture > independent implementations. While other implementations are > more architecture specific. Single stepping inline wouldnt go > well with multithreaded process. > > Even though XOL vma has its own issues, we will go with it since > other implementations seem to have more complications. > > we would look forward to implementing boosters later. > Later on, if we come across another techniques with lesser > side-effects than the XOL vma, we would switch to using them. How about modifying glibc to reserve like 64 bytes on the TLS structure it has and storing the ins and possible boost jmp there? Since each thread can only have a single trap at any one time that should be enough. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/