From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: linux-next: add utrace tree Date: Wed, 27 Jan 2010 13:53:19 -0500 Message-ID: <1264618399.31321.470.camel@gandalf.stny.rr.com> References: <20100121013822.28781960.sfr@canb.auug.org.au> <20100122005147.GD22003@redhat.com> <20100121170541.7425ff10.akpm@linux-foundation.org> <20100122182827.GA13185@redhat.com> <20100122200129.GG22003@redhat.com> <20100122221348.GA4263@redhat.com> <1264575134.4283.1983.camel@laptop> <1264600792.31321.464.camel@gandalf.stny.rr.com> <4B607B1A.3080007@zytor.com> Reply-To: rostedt@goodmis.org Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Return-path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:52772 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753136Ab0A0SxX (ORCPT ); Wed, 27 Jan 2010 13:53:23 -0500 In-Reply-To: <4B607B1A.3080007@zytor.com> Sender: linux-next-owner@vger.kernel.org List-ID: To: "H. Peter Anvin" Cc: Linus Torvalds , Peter Zijlstra , Tom Tromey , Kyle Moffett , "Frank Ch. Eigler" , Oleg Nesterov , Andrew Morton , Stephen Rothwell , Fr??d??ric Weisbecker , LKML , Arnaldo Carvalho de Melo , linux-next@vger.kernel.org, utrace-devel@redhat.com, Thomas Gleixner , JimKeniston , Arjan van de Ven On Wed, 2010-01-27 at 09:42 -0800, H. Peter Anvin wrote: > On 01/27/2010 05:59 AM, Steven Rostedt wrote: > > I think the issue was that ring 0 was never meant to do that, where as, > > ring 3 does it all the time. Doesn't the dynamic library modify its > > text? > > > > No, it has nothing to do with ring. It has to do with modifying code > that another CPU could be executing at the same time, and with modifying > code on the same processor through another virtual alias (they are > different issues.) The same issues apply regardless of the CPL of the > processor. Thanks for clarifying. -- Steve