From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60F81C1B0E3 for ; Wed, 11 Jul 2018 19:56:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7233213A2 for ; Wed, 11 Jul 2018 19:56:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7233213A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733252AbeGKUCY (ORCPT ); Wed, 11 Jul 2018 16:02:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:56110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726399AbeGKUCY (ORCPT ); Wed, 11 Jul 2018 16:02:24 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 650D020C0E; Wed, 11 Jul 2018 19:56:30 +0000 (UTC) Date: Wed, 11 Jul 2018 15:56:28 -0400 From: Steven Rostedt To: Francis Deslauriers Cc: Mathieu Desnoyers , Masami Hiramatsu , Peter Zijlstra , linux-kernel , torvalds@linux-foundation.org Subject: Re: [PATCH 2/2] kprobe: fix: Add ftrace_ops_assist_func to kprobe blacklist Message-ID: <20180711155628.78b0fd83@gandalf.local.home> In-Reply-To: References: <1500044315-9508-1-git-send-email-francis.deslauriers@efficios.com> <1500044315-9508-3-git-send-email-francis.deslauriers@efficios.com> <20170714142900.1c91949c@gandalf.local.home> <20180316112517.66bdd85a@gandalf.local.home> <229385456.11580.1521217739037.JavaMail.zimbra@efficios.com> <20180316124134.30fa47d5@gandalf.local.home> <20180316124840.3e83bbec@gandalf.local.home> <1577244734.11604.1521222781948.JavaMail.zimbra@efficios.com> <20180317091334.55f1fc325c26deaa4d4a4d19@kernel.org> <20180317102211.a648f26ae0d5a53d95c63022@kernel.org> <20180703183048.1eeeef4a@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Jul 2018 15:34:30 -0400 Francis Deslauriers wrote: > Hi Steven, > I tested it and it prevents the kernel crash I am witnessing. > As for the side-effect that Masami mentioned regarding not being able to probe > function inside the trace_kprobe.c file, I suggest we move the target > function in > its own separate compile unit so it can be compiled with the ftrace cflags. > See patch below. > The patch below looks fine and so does Masami's. But there's too many patches within emails (not separated out). I have no idea what to apply. I'm not going to apply anything that is not sent as a proper patch (ie. any patch within a separate thread, like the patch below). -- Steve > Thanks > Francis > > >From d5a3645bd0046f28275d6b60207958f2751c1f47 Mon Sep 17 00:00:00 2001 > From: Francis Deslauriers > Date: Wed, 11 Jul 2018 12:34:22 -0400 > Subject: [PATCH] selftest/ftrace: Move kprobe selftest function to separate > compile unit > > Move selftest function to its own compile unit so it can be compiled > with the ftrace cflags (CC_FLAGS_FTRACE) allowing it to be probed > during the ftrace startup tests. > > Signed-off-by: Francis Deslauriers > --- > kernel/trace/Makefile | 5 +++++ > kernel/trace/trace_kprobe.c | 12 +----------- > kernel/trace/trace_kprobe_selftest.c | 10 ++++++++++ > kernel/trace/trace_kprobe_selftest.h | 7 +++++++ > 4 files changed, 23 insertions(+), 11 deletions(-) > create mode 100644 kernel/trace/trace_kprobe_selftest.c > create mode 100644 kernel/trace/trace_kprobe_selftest.h > > diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile > index e2538c7..e38771e 100644 > --- a/kernel/trace/Makefile > +++ b/kernel/trace/Makefile > @@ -13,6 +13,11 @@ obj-y += trace_selftest_dynamic.o > endif > endif > > +ifdef CONFIG_FTRACE_STARTUP_TEST > +CFLAGS_trace_kprobe_selftest.o = $(CC_FLAGS_FTRACE) > +obj-$(CONFIG_KPROBE_EVENTS) += trace_kprobe_selftest.o > +endif > + > # If unlikely tracing is enabled, do not trace these files > ifdef CONFIG_TRACING_BRANCHES > KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 952dc2a..3fe966f 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -24,6 +24,7 @@ > #include > > #include "trace_probe.h" > +#include "trace_kprobe_selftest.h" > > #define KPROBE_EVENT_SYSTEM "kprobes" > #define KRETPROBE_MAXACTIVE_MAX 4096 > @@ -1560,17 +1561,6 @@ fs_initcall(init_kprobe_trace); > > > #ifdef CONFIG_FTRACE_STARTUP_TEST > -/* > - * The "__used" keeps gcc from removing the function symbol > - * from the kallsyms table. 'noinline' makes sure that there > - * isn't an inlined version used by the test method below > - */ > -static __used __init noinline int > -kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6) > -{ > - return a1 + a2 + a3 + a4 + a5 + a6; > -} > - > static __init struct trace_event_file * > find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) > { > diff --git a/kernel/trace/trace_kprobe_selftest.c > b/kernel/trace/trace_kprobe_selftest.c > new file mode 100644 > index 0000000..a3d2090 > --- /dev/null > +++ b/kernel/trace/trace_kprobe_selftest.c > @@ -0,0 +1,10 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Function used during the kprobe self test. This function is in a seperate > + * compile unit so it can be compile with CC_FLAGS_FTRACE to ensure that it > + * can be probed by the selftests. > + */ > +int kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int > a5, int a6) > +{ > + return a1 + a2 + a3 + a4 + a5 + a6; > +} > diff --git a/kernel/trace/trace_kprobe_selftest.h > b/kernel/trace/trace_kprobe_selftest.h > new file mode 100644 > index 0000000..9243d4e > --- /dev/null > +++ b/kernel/trace/trace_kprobe_selftest.h > @@ -0,0 +1,7 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Function used during the kprobe self test. This function is in a seperate > + * compile unit so it can be compile with CC_FLAGS_FTRACE to ensure that it > + * can be probed by the selftests. > + */ > +int kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int > a5, int a6);