From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752606Ab0CTAOK (ORCPT ); Fri, 19 Mar 2010 20:14:10 -0400 Received: from rcsinet11.oracle.com ([148.87.113.123]:51928 "EHLO rcsinet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752427Ab0CTAOH (ORCPT ); Fri, 19 Mar 2010 20:14:07 -0400 Message-ID: <4BA41305.7070403@oracle.com> Date: Fri, 19 Mar 2010 17:12:53 -0700 From: Randy Dunlap Organization: Oracle Linux Engineering User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0 MIME-Version: 1.0 To: rostedt@goodmis.org CC: Linux Kernel Mailing List , Frederic Weisbecker , Mathieu Desnoyers Subject: Re: 2.6.33 GP fault only when built with tracing References: <4BA2B69D.3000309@oracle.com> <1268956555.758.18.camel@gandalf.stny.rr.com> In-Reply-To: <1268956555.758.18.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt355.oracle.com [141.146.40.155] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090208.4BA41348.005F:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/18/10 16:55, Steven Rostedt wrote: > On Thu, 2010-03-18 at 16:26 -0700, Randy Dunlap wrote: >> I can build/boot 2.6.33 with CONFIG_TRACE/TRACING disabled successfully, >> but when I enable lots of tracing config options and then boot with >> ftrace=nop on the kernel command line, I see a GP fault when the parport & >> parport_pc modules are loading/initializing. > > Do you see it without adding the "ftrace=nop"? The only thing that > should do is expand the ring buffer on boot up. Yes, it happens with or without "ftrace=nop" as a kernel boot argument. >> >> It happens in drivers/parport/share.c::parport_register_device(), when that >> function calls try_module_get(). >> >> If I comment out the trace_module_get() calls in include/linux/module.h, >> the kernel boots with no problems. > > > Interesting. Well, trace_module_get() is a TRACE_EVENT tracepoint. But > should be disabled here. It may be something to do with DEFINE_TRACE. > > (added Mathieu to Cc since he wrote that code) -- ~Randy