From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752133AbbAMMWg (ORCPT ); Tue, 13 Jan 2015 07:22:36 -0500 Received: from smtprelay0063.hostedemail.com ([216.40.44.63]:43501 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751637AbbAMMWf (ORCPT ); Tue, 13 Jan 2015 07:22:35 -0500 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::,RULES_HIT:41:355:379:541:599:800:960:968:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2198:2199:2393:2553:2559:2562:3138:3139:3140:3141:3142:3353:3622:3865:3866:3867:3868:3870:3871:3872:3874:4362:4470:5007:6119:6261:7875:7903:8531:10004:10400:10848:10967:11232:11658:11914:12043:12050:12296:12517:12519:12740:13069:13161:13229:13311:13357:13972:14096:14097:21060:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: fly99_6daee5a452424 X-Filterd-Recvd-Size: 2005 Date: Tue, 13 Jan 2015 07:22:32 -0500 From: Steven Rostedt To: Masami Hiramatsu Cc: LKML , vvs@sw.ru Subject: Re: Bug with jprobes and function graph tracer Message-ID: <20150113072232.451c599b@gandalf.local.home> In-Reply-To: <54B503F5.4020509@hitachi.com> References: <20150108122016.0241f713@gandalf.local.home> <54B503F5.4020509@hitachi.com> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 13 Jan 2015 20:39:33 +0900 Masami Hiramatsu wrote: > > Yeah we should try to fix this, but not so high priority since jprobe > is not used so frequently. I guess one easy solution is adding notrace > to all jprobe handlers for hiding it from function-graph tracer. > If there is a way to check a function is notrace or not, I can use that > in register_jprobe and reject it if the handler is not "notrace"ed. :) Adding notrace should be the last resort. Every notrace in the kernel makes function tracing a little more useless. It bothers me even more when notrace is added because of function graph tracing but the function still works for function tracing. I worked on this for the last few days and have a patch that fixes the problem. I'll be posting it later today. It also uncovered another unrelated bug that I worked on yesterday, otherwise I would have posted these fixes already. I have a fix for the other bug now but it needs to be cleaned up (remove all the debugging prints from it). When that's complete I'll post the patches and get them ready for mainline and stable. Thanks, -- Steve