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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 DF7FEECDE44 for ; Mon, 22 Oct 2018 01:34:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95C512083E for ; Mon, 22 Oct 2018 01:34:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 95C512083E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com 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 S1726970AbeJVJut (ORCPT ); Mon, 22 Oct 2018 05:50:49 -0400 Received: from terminus.zytor.com ([198.137.202.136]:59457 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725884AbeJVJus (ORCPT ); Mon, 22 Oct 2018 05:50:48 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w9M1XqeH2376134 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sun, 21 Oct 2018 18:33:52 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w9M1XpXk2376131; Sun, 21 Oct 2018 18:33:51 -0700 Date: Sun, 21 Oct 2018 18:33:51 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Masami Hiramatsu Message-ID: Cc: tglx@linutronix.de, oleg@redhat.com, torvalds@linux-foundation.org, namit@vmware.com, mingo@kernel.org, alexei.starovoitov@gmail.com, hpa@zytor.com, mhiramat@kernel.org, peterz@infradead.org, linux-kernel@vger.kernel.org, luto@kernel.org, stable@vger.kernel.org, bp@alien8.de Reply-To: hpa@zytor.com, mingo@kernel.org, namit@vmware.com, alexei.starovoitov@gmail.com, torvalds@linux-foundation.org, oleg@redhat.com, tglx@linutronix.de, bp@alien8.de, stable@vger.kernel.org, mhiramat@kernel.org, peterz@infradead.org, luto@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <154002887331.7627.10194920925792947001.stgit@devbox> References: <154002887331.7627.10194920925792947001.stgit@devbox> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] kprobes/x86: Use preempt_enable() in optimized_callback() Git-Commit-ID: 2e62024c265aa69315ed02835623740030435380 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 2e62024c265aa69315ed02835623740030435380 Gitweb: https://git.kernel.org/tip/2e62024c265aa69315ed02835623740030435380 Author: Masami Hiramatsu AuthorDate: Sat, 20 Oct 2018 18:47:53 +0900 Committer: Ingo Molnar CommitDate: Mon, 22 Oct 2018 03:31:01 +0200 kprobes/x86: Use preempt_enable() in optimized_callback() The following commit: a19b2e3d7839 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”) removed local_irq_save/restore() from optimized_callback(), the handler might be interrupted by the rescheduling interrupt and might be rescheduled - so we must not use the preempt_enable_no_resched() macro. Use preempt_enable() instead, to not lose preemption events. [ mingo: Improved the changelog. ] Reported-by: Nadav Amit Signed-off-by: Masami Hiramatsu Acked-by: Peter Zijlstra (Intel) Cc: Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Thomas Gleixner Cc: dwmw@amazon.co.uk Fixes: a19b2e3d7839 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”) Link: http://lkml.kernel.org/r/154002887331.7627.10194920925792947001.stgit@devbox Signed-off-by: Ingo Molnar --- arch/x86/kernel/kprobes/opt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index eaf02f2e7300..40b16b270656 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -179,7 +179,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) opt_pre_handler(&op->kp, regs); __this_cpu_write(current_kprobe, NULL); } - preempt_enable_no_resched(); + preempt_enable(); } NOKPROBE_SYMBOL(optimized_callback);