From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753944AbYIWBWd (ORCPT ); Mon, 22 Sep 2008 21:22:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754713AbYIWBWV (ORCPT ); Mon, 22 Sep 2008 21:22:21 -0400 Received: from tomts10.bellnexxia.net ([209.226.175.54]:40882 "EHLO tomts10-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753861AbYIWBWV (ORCPT ); Mon, 22 Sep 2008 21:22:21 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqEEANvd10hMQWq+/2dsb2JhbACBXbUZgWY Date: Mon, 22 Sep 2008 21:22:19 -0400 From: Mathieu Desnoyers To: "Frank Ch. Eigler" Cc: Paul Mundt , linux-kernel@vger.kernel.org, Linus Torvalds , Roland McGrath Subject: Re: [PATCH] [RFC] tracehook: Hook in syscall tracing markers. Message-ID: <20080923012219.GB24937@Krystal> References: <20080921021630.GA6443@linux-sh.org> <20080922012841.GA6199@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20080922012841.GA6199@redhat.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 21:20:41 up 110 days, 6:01, 7 users, load average: 0.67, 0.47, 0.31 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Frank Ch. Eigler (fche@redhat.com) wrote: > Hi - > > > At kernel summit, the idea that syscall tracing was generally desirable > > for tracing was mentioned several times, as was the argument that kernel > > developers aren't placing markers in meaningful locations. This is a > > simple patch to try and do that for the syscall case.[...] > > One problem with this is that a separate mechanism would be needed to > activate these tracehook_report_* calls in the first place: the > management of the per-task TIF_SYSCALL_TRACE flag. This is one of the > things the utrace API makes straightforward, in which case its own > native syscall reporting callbacks can be used directly. > > - FChE > There is already a series of patches in the -lttng tree which adds TIF_KERNEL_TRACE to every architecture. It basically enables syscall tracing for every threads running on the system. It't the best way I found to do system-wide syscall tracing without changing anything of the assembly code except adding one flag to the tested flags. Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68