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=-9.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 ECE52C67863 for ; Sat, 20 Oct 2018 09:48:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5522A21523 for ; Sat, 20 Oct 2018 09:48:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xpWP8pPq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5522A21523 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1727382AbeJTR6J (ORCPT ); Sat, 20 Oct 2018 13:58:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:35992 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727178AbeJTR6J (ORCPT ); Sat, 20 Oct 2018 13:58:09 -0400 Received: from localhost.localdomain (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 DA97A21521; Sat, 20 Oct 2018 09:48:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540028898; bh=8P5+7Uw8egUr/TPahnp3yRc5sRGYzJAh/z0nry+VH7g=; h=From:To:Cc:Subject:Date:From; b=xpWP8pPqbiHDEEUN9PLXWEO2ErGJ4SSyiAbn88vXvF6CCRLayWFJ3K8nJEvtDhGrR TZCdGXbKoZYj67oAGSHMrA8CNA0SSU3iNMT+WmtHDlxOsKvHO3qfTxAkxWzI1vi3Iv /oNFM2bPaMsvhGCznOXWHPMIsxlplmlqS6M9y284= From: Masami Hiramatsu To: Ingo Molnar Cc: Andy Lutomirski , Alexei Starovoitov , Oleg Nesterov , Peter Zijlstra , "H . Peter Anvin" , Thomas Gleixner , X86 ML , Borislav Petkov , dwmw@amazon.co.uk, Masami Hiramatsu , linux-kernel@vger.kernel.org Subject: [PATCH -tip] kprobes/x86: Use preempt_enable() in optimized_callback() Date: Sat, 20 Oct 2018 18:47:53 +0900 Message-Id: <154002887331.7627.10194920925792947001.stgit@devbox> X-Mailer: git-send-email 2.13.6 User-Agent: StGit/0.17.1-dirty 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 Since commit a19b2e3d7839 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”) removes local_irq_save/restore() from optimized_callback(), the handler does not protected against reschedule interrupt. If it is able to be preempted (rescheduled) by such interrupt, we don't need to use _no_resched macro. Let's use preempt_enable() instead. Fixes: a19b2e3d7839 ("kprobes/x86: Remove IRQ disabling from ftrace-based/optimized kprobes”) Link: https://lkml.kernel.org/r/37CB98C2-AF9B-475B-8B2D-7B414DC491F3@vmware.com Reported-by: Nadav Amit Signed-off-by: Masami Hiramatsu --- 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);