From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wyh971PnBzDr4V for ; Thu, 29 Jun 2017 10:58:03 +1000 (AEST) Date: Thu, 29 Jun 2017 09:57:57 +0900 From: Masami Hiramatsu To: "Naveen N. Rao" Cc: Steven Rostedt , Ananth N Mavinakayanahalli , Michael Ellerman , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 2/2] selftests/ftrace: Update multiple kprobes test for powerpc Message-Id: <20170629095757.2f1fea73ad2e61ad08618e15@kernel.org> In-Reply-To: <20170628184324.zpfe6f54jbhzxq5g@naverao1-tp.localdomain> References: <20170622180738.e97092d4fa6458b9199a03d7@kernel.org> <20170622170325.qznheui7eydkdnmv@naverao1-tp.localdomain> <20170624023021.92f2f90f0e09314ac9bdb87a@kernel.org> <20170624200610.f3aee818b8f6ff2631e0d56a@kernel.org> <20170628092846.uwc55zuq7dsbrzho@naverao1-tp.localdomain> <20170628231650.6fb5d14fb00923d29bd313d7@kernel.org> <20170628184324.zpfe6f54jbhzxq5g@naverao1-tp.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 29 Jun 2017 00:13:24 +0530 "Naveen N. Rao" wrote: > On 2017/06/28 11:16PM, Masami Hiramatsu wrote: > > > > diff --git > > > > a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc > > > > b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc > > > > new file mode 100644 > > > > index 0000000..d259031 > > > > --- /dev/null > > > > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_eventname.tc > > > > @@ -0,0 +1,28 @@ > > > > +#!/bin/sh > > > > +# description: Kprobe event auto/manual naming > > > > + > > > > +disable_events > > > > +echo > kprobe_events > > > > + > > > > +:;: "Add an event on function without name" ;: > > > > + > > > > +FUNC=`grep -m 10 " [tT] [^.]*$" /proc/kallsyms | tail -n 1 | cut -f 3 -d " "` > > > > > > On powerpc, this always ends up using a blacklisted function. So, I > > > think we need a way to find a function that is not black listed. > > > > Hmm, if we increase the -m argument, like -m 100, is that still > > in a blacklisted function? > > Yes, most of the initial symbols are exception vectors which are > blacklisted. Hmm, then how about this? :) grep _stext -A 1000 | grep -m 10 " [tT] [^.]*$" /proc/kallsyms > > > > > > However, one of the issues is that debugfs does not show all the address > > > ranges that are blacklisted. I am coming up with a way to address that > > > and will post patches once I have it working. > > > > Would you find that is only on powerpc or generic issue? > > I meant the address _ranges_ that are blacklisted such as the ones with > __kprobes annotation and __entry_text and so on. I see, but we can also check the address by comparing the address of symbols, which also can be retrieved from kallsyms. Since the test case is also applied to stable kernel, I don't want to make it depending on some special kernel tweaks. > > > > > > > > With those patches, we should be able to select symbols that are not > > > blacklisted. > > > > Or, maybe we can use generic function, like "schedule" or "vfs_read" > > etc. > > Yes, I think this will be good for the generic test, but may not help > selecting a dot symbol on powerpc. Right, and it depends on what gcc version and option is specified. So, maybe we can skip the test if there is no such symbols. I intended to test the symbols with some dot-suffix, but it seems ppc64 has dot-started symbols, right? If there is no dot-suffixed symbols, I think this test should skip the test case. Thank you, -- Masami Hiramatsu