From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751209AbeCIMkK (ORCPT ); Fri, 9 Mar 2018 07:40:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:41646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbeCIMkJ (ORCPT ); Fri, 9 Mar 2018 07:40:09 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BA91206B2 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: Thomas Gleixner , Ingo Molnar Cc: x86@kernel.org, Masami Hiramatsu , Yang Bo , Ingo Molnar , "H . Peter Anvin" , linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , Andrew Morton , Steven Rostedt , Laura Abbott , Josef Bacik , Alexei Starovoitov Subject: [RFC PATCH -tip 9/9] tracing: kprobes: Fix to not enabling preemption Date: Fri, 9 Mar 2018 21:39:45 +0900 Message-Id: <152059918532.4214.8326814684091028387.stgit@devbox> X-Mailer: git-send-email 2.13.6 In-Reply-To: <152059891712.4214.9539716544254881611.stgit@devbox> References: <152059891712.4214.9539716544254881611.stgit@devbox> 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 Since kprobes pre_handler doesn't need to recover preemption even if it modifies regs->ip anymore, this fixes to remove the preempt_enable_no_resched() from pre_handler. Signed-off-by: Masami Hiramatsu --- kernel/trace/trace_kprobe.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 5ce9b8cf7be3..6c894e2be8d6 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1221,12 +1221,9 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) * We need to check and see if we modified the pc of the * pt_regs, and if so clear the kprobe and return 1 so that we * don't do the single stepping. - * The ftrace kprobe handler leaves it up to us to re-enable - * preemption here before returning if we've modified the ip. */ if (orig_ip != instruction_pointer(regs)) { reset_current_kprobe(); - preempt_enable_no_resched(); return 1; } if (!ret)