From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751205AbdISJ64 (ORCPT ); Tue, 19 Sep 2017 05:58:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:51518 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbdISJ6z (ORCPT ); Tue, 19 Sep 2017 05:58:55 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BEC18218E9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mhiramat@kernel.org From: Masami Hiramatsu To: Ingo Molnar , mingo@redhat.com Cc: x86@kernel.org, Steven Rostedt , Masami Hiramatsu , linux-kernel@vger.kernel.org, Peter Zijlstra , Ananth N Mavinakayanahalli , Thomas Gleixner , "H . Peter Anvin" , "Paul E . McKenney" , Alexei Starovoitov , Alexei Starovoitov Subject: [PATCH -tip v3 0/7] kprobes/x86: Preempt related enhancements Date: Tue, 19 Sep 2017 18:58:17 +0900 Message-Id: <150581509713.32348.1905525476438163954.stgit@devbox> X-Mailer: git-send-email 2.13.5 User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Here is the 3rd version of the series to improve preempt related behavior in kprobes/x86. This actually includes many enhancements/fixes from the 2nd version, which is https://lkml.org/lkml/2017/9/11/482 With the previous patch, lkp-bot reported that an issue ( https://lkml.org/lkml/2017/9/14/3 ) and I couldn't reproduce it. However, I found a suspicious bug and fixed it ([2/7]). Also, while I was checking the correct condition for *probe handlers in Documentation/kprobes.txt, I also found that current implementations for ftrace-based kprobe and optprobe were mis-reading the document. >>From the document, handlers must be run with preempt- disabled, but interrupt disabling is not guaranteed. So in the middle of this series, patches ([4/7],[5/7], [6/7]) adding preempt-disabling and removing irq-disabling. And at last, I placed the original patch (Enable optprobe with CONFIG_PREEMPT). The others are just for making sure this fix works well. - [1/7] is just adding preemptible checker in kprobe smake tests so that we can easily find mistake. - [3/7] is adding an assert if user tries to change execution path in optprobe, which is obviously prohibited in the document (there also be how to avoid it.) Thank you, --- Masami Hiramatsu (7): kprobes: Improve smoke test to check preemptible kprobes/x86: Move get_kprobe_ctlblk in irq-disabled block kprobes: Warn if optprobe handler tries to change execution path kprobes/x86: Disable preempt in optprobe kprobes/x86: Disable preempt ftrace-based jprobe kprobes/x86: Remove disable_irq from ftrace-based/optimized kprobe kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT arch/Kconfig | 2 +- arch/x86/kernel/kprobes/ftrace.c | 32 ++++++++++++++++---------------- arch/x86/kernel/kprobes/opt.c | 8 +++----- kernel/kprobes.c | 23 +++++++++++++++++------ kernel/test_kprobes.c | 20 ++++++++++++++++++++ 5 files changed, 57 insertions(+), 28 deletions(-) -- Masami Hiramatsu