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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 CAD23C5519F for ; Sat, 14 Nov 2020 22:59:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CE2624073 for ; Sat, 14 Nov 2020 22:59:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="TTjjkSwx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726265AbgKNW6x (ORCPT ); Sat, 14 Nov 2020 17:58:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:54880 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726140AbgKNW6w (ORCPT ); Sat, 14 Nov 2020 17:58:52 -0500 Received: from localhost (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 D321E24073; Sat, 14 Nov 2020 22:58:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605394732; bh=mWo9BhwcebEeYNtQDho2WW/HLm5sQAVSBBwcsj5iFts=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TTjjkSwxxRCE4dwgHBavciPrI3W5heX94zUgtHV9pBQCqrPLv2u0bdCBs5qk4Mz5g 7NVSJl3uZobCrrx602q+sTjLWl9N6RNyYxqfI0mKPnU8Y+JB6KnJh7WT6VxC4Uo5wE cRCCkRWC/ZkbN/B2nwxV6I8/W5O6uokykuNXqdAY= Date: Sat, 14 Nov 2020 17:58:50 -0500 From: Sasha Levin To: Masami Hiramatsu Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, "Steven Rostedt (VMware)" , Peter Zijlstra Subject: Re: [PATCH AUTOSEL 4.19 18/21] kprobes: Tell lockdep about kprobe nesting Message-ID: <20201114225850.GH403069@sasha-vm> References: <20201110035541.424648-1-sashal@kernel.org> <20201110035541.424648-18-sashal@kernel.org> <20201110154458.546c220fcae09592cf5282b9@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20201110154458.546c220fcae09592cf5282b9@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 10, 2020 at 03:44:58PM +0900, Masami Hiramatsu wrote: >Hi, > >On Mon, 9 Nov 2020 22:55:38 -0500 >Sasha Levin wrote: > >> From: "Steven Rostedt (VMware)" >> >> [ Upstream commit 645f224e7ba2f4200bf163153d384ceb0de5462e ] >> >> Since the kprobe handlers have protection that prohibits other handlers from >> executing in other contexts (like if an NMI comes in while processing a >> kprobe, and executes the same kprobe, it will get fail with a "busy" >> return). Lockdep is unaware of this protection. Use lockdep's nesting api to >> differentiate between locks taken in INT3 context and other context to >> suppress the false warnings. >> >> Link: https://lore.kernel.org/r/20201102160234.fa0ae70915ad9e2b21c08b85@kernel.org >> > >This fixes a lockdep false positive warning comes from commit e03b4a084ea6 >("kprobes: Remove NMI context check"). Does anyone report that happen on the >stable kernel? > >If not, you do not need this patch for stable kernels. I'll drop it, thanks! -- Thanks, Sasha