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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 7B28DC43441 for ; Sun, 11 Nov 2018 23:44:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41BF120818 for ; Sun, 11 Nov 2018 23:44:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="KFeMMETB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 41BF120818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.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 S2387541AbeKLJea (ORCPT ); Mon, 12 Nov 2018 04:34:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:40408 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727357AbeKLITN (ORCPT ); Mon, 12 Nov 2018 03:19:13 -0500 Received: from localhost (unknown [206.108.79.134]) (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 6652F21508; Sun, 11 Nov 2018 22:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975357; bh=IH1d2KfKDxiFo1HhZj7IK4gIknAAcIbvQ7+/fclOn6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KFeMMETBdat1mezo8aPh9EFiQhmMsT58RaUh80hzCuw+ysNHTqDr0A0vOb+QD1/1S AtiyVJWzKivNRJ+G7xAWFpDGe4Rmnn+Hh/XRphhqKFlwBpHRJxCAZlRi1VXdvIZwSB iDRPl/zLaiAh8iV4qA1dJ2RqA4bCP+q0LbWOYzkk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nadav Amit , Masami Hiramatsu , "Peter Zijlstra (Intel)" , Alexei Starovoitov , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Oleg Nesterov , Thomas Gleixner , dwmw@amazon.co.uk, Ingo Molnar Subject: [PATCH 4.18 023/350] kprobes/x86: Use preempt_enable() in optimized_callback() Date: Sun, 11 Nov 2018 14:18:07 -0800 Message-Id: <20181111221708.139574483@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221707.043394111@linuxfoundation.org> References: <20181111221707.043394111@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu commit 2e62024c265aa69315ed02835623740030435380 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kprobes/opt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -179,7 +179,7 @@ optimized_callback(struct optimized_kpro opt_pre_handler(&op->kp, regs); __this_cpu_write(current_kprobe, NULL); } - preempt_enable_no_resched(); + preempt_enable(); } NOKPROBE_SYMBOL(optimized_callback);