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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 BF499C35242 for ; Tue, 11 Feb 2020 19:21:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E61220842 for ; Tue, 11 Feb 2020 19:21:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="QvD20COf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731638AbgBKTVd (ORCPT ); Tue, 11 Feb 2020 14:21:33 -0500 Received: from mail-pj1-f65.google.com ([209.85.216.65]:53425 "EHLO mail-pj1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729800AbgBKTVd (ORCPT ); Tue, 11 Feb 2020 14:21:33 -0500 Received: by mail-pj1-f65.google.com with SMTP id n96so1763425pjc.3 for ; Tue, 11 Feb 2020 11:21:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=LWdO903JlL7mrIroJ1DR4H0Lf0OnGW3IvW4RvhYAFg0=; b=QvD20COfVzxuay6xGJSzAAWXcjptzM8MyBsKCfYGfkNUpP3ZsfpRCnB1a9xLwfnTHB wKNeAxR0CVstaTCqWBMgJCLOT41JKo13HUck+vjHHNU6vzraPrnd3cDFUvgFWIPAtFMt nAsJb50vycy90MUlcKEG44K3kaE7ytB6v2oE8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=LWdO903JlL7mrIroJ1DR4H0Lf0OnGW3IvW4RvhYAFg0=; b=VyJTZodQZ3eEjfmmMEvY0yXYwO6B85KjITY4ml4GGXTt8Hn/j80tA8NHP04HvPOWqv n5x6toHK5PFiUsluI1jsyHhRtSvJaqRMJ9f0PRbG1pRf54R5Y78ZYxoylQNbEujxSFNJ jQdtBwaJSfF2IBZRvyL4WfZpv9L8bw8bAd15o4WSz0IEnVXlm4erJlyUXZEmIx9ewGSi vGq1TV+7W5xL0FV/22IMfUXY/MWKL9WDfIYMj/1qMjhSsBCWiuNC3ehtLYhHBGkkEJXi hKQnojBLonjgkJoxl9iHhA1bfXiSoJuHFEJZRfQ/FcvCgopNpMStIWaQrkgFL+AyesMU gdSw== X-Gm-Message-State: APjAAAU5F9uhe5YgdV6npHz/h7e9kerbbDvPA94h5y5sa+oCMeQqyxnQ SvH7vWn7JyR4IbGXY37fxuQ9LQ== X-Google-Smtp-Source: APXvYqw1YwEZ93PZj55gFovRIY7+WfkCv4LbdL59T6UWNYBnl5teLRUx7UPTsrLJB/UZSKSu0YhImQ== X-Received: by 2002:a17:90a:9311:: with SMTP id p17mr5315663pjo.140.1581448892021; Tue, 11 Feb 2020 11:21:32 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f43sm4267444pje.23.2020.02.11.11.21.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Feb 2020 11:21:31 -0800 (PST) Date: Tue, 11 Feb 2020 11:21:29 -0800 From: Kees Cook To: Konstantin Khlebnikov Cc: Andrew Morton , linux-kernel@vger.kernel.org, Sasha Levin , Petr Mladek , Peter Zijlstra , Greg Kroah-Hartman , Steven Rostedt , Sergey Senozhatsky , Dmitry Monakhov Subject: Re: [PATCH] lib/test_lockup: test module to generate lockups Message-ID: <202002111120.91782E0686@keescook> References: <158132859146.2797.525923171323227836.stgit@buzz> <202002101725.EE6D5A6@keescook> <5e5ee6b7-68a9-1bcc-66c5-814e40a627be@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5e5ee6b7-68a9-1bcc-66c5-814e40a627be@yandex-team.ru> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 11, 2020 at 03:57:42PM +0300, Konstantin Khlebnikov wrote: > On 11/02/2020 04.26, Kees Cook wrote: > > On Mon, Feb 10, 2020 at 12:56:31PM +0300, Konstantin Khlebnikov wrote: > > > CONFIG_TEST_LOCKUP=m adds module "test_lockup" that helps to make sure > > > that watchdogs and lockup detectors are working properly. > > > > Isn't this all already possible with CONFIG_LKDTM ? > > Yep, LKDTM covers some cases. But they are unrecoverable. > > It seems LKDTM is more like a fixed set of unit tests while > test_lockup is a flexible tool for stress load. Okay, cool. I just wanted to make sure you'd seen LKDTM and there wasn't too much wheel-reinvention happening. :) Thanks for checking! -Kees -- Kees Cook