From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752262AbcDZNgI (ORCPT ); Tue, 26 Apr 2016 09:36:08 -0400 Received: from smtprelay0083.hostedemail.com ([216.40.44.83]:54337 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751507AbcDZNgG (ORCPT ); Tue, 26 Apr 2016 09:36:06 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::,RULES_HIT:41:334:355:368:369:379:541:599:800:960:973:982:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2899:3138:3139:3140:3141:3142:3353:3622:3865:3866:3867:3868:3870:3871:3872:3874:4250:5007:6119:6261:7875:7903:8545:9010:10004:10400:10848:10967:11026:11232:11658:11914:12296:12438:12517:12519:12740:13069:13311:13357:13439:14096:14097:14181:14659:14721:21080:21212:21324:30003:30029:30030:30051:30054:30070:30089:30090:30091,0,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,LFtime:3,LUA_SUMMARY:none X-HE-Tag: peace09_6ef40a5fc904d X-Filterd-Recvd-Size: 2636 Date: Tue, 26 Apr 2016 09:36:01 -0400 From: Steven Rostedt To: Thiago Jung Bauermann Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Michael Ellerman , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v2] ftrace: Match dot symbols when searching functions on ppc64 Message-ID: <20160426093601.72b17896@gandalf.local.home> In-Reply-To: <1461621374-14408-1-git-send-email-bauerman@linux.vnet.ibm.com> References: <1461621374-14408-1-git-send-email-bauerman@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; 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 Mon, 25 Apr 2016 18:56:14 -0300 Thiago Jung Bauermann wrote: > In the ppc64 big endian ABI, function symbols point to function > descriptors. The symbols which point to the function entry points > have a dot in front of the function name. Consequently, when the > ftrace filter mechanism searches for the symbol corresponding to > an entry point address, it gets the dot symbol. > > As a result, ftrace filter users have to be aware of this ABI detail on > ppc64 and prepend a dot to the function name when setting the filter. > > The perf probe command insulates the user from this by ignoring the dot > in front of the symbol name when matching function names to symbols, > but the sysfs interface does not. This patch makes the ftrace filter > mechanism do the same when searching symbols. > > Fixes the following failure in ftracetest's kprobe_ftrace.tc: > > .../kprobe_ftrace.tc: line 9: echo: write error: Invalid argument > > That failure is on this line of kprobe_ftrace.tc: > > echo _do_fork > set_ftrace_filter > > This is because there's no _do_fork entry in the functions list: > > # cat available_filter_functions | grep _do_fork > ._do_fork > > This change introduces no regressions on the perf and ftracetest > testsuite results. > > Cc: Steven Rostedt > Cc: Ingo Molnar > Cc: Michael Ellerman > Cc: linuxppc-dev@lists.ozlabs.org > Signed-off-by: Thiago Jung Bauermann > --- Acked-by: Steven Rostedt This can go through the ppc tree. -- Steve