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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 1D2CCC10DCE for ; Fri, 13 Mar 2020 08:31:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E288720724 for ; Fri, 13 Mar 2020 08:31:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="YR6QRrnO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726582AbgCMIbi (ORCPT ); Fri, 13 Mar 2020 04:31:38 -0400 Received: from merlin.infradead.org ([205.233.59.134]:57026 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726420AbgCMIbh (ORCPT ); Fri, 13 Mar 2020 04:31:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=MAsAcM05mXkzCsPvayDcJZuYQVlAkvzdedkH1NlOMWc=; b=YR6QRrnO3fKBbY/PgCXjSBYL/i YFGw13odm0+qWLyhzR1u8l265TNuHgGhITEyT0bhvgbBK7bQTo1TfxZMt088AWymnNkSL6YQE2BnJ jk8gfR5ZC2CpEYpmf5N2D5pM8ZtawQO9LZL0rYjyJJX3VK5+Ali96Cg0pDeHKFRaUlJCFw6csHEdm dxdeo4abnRmhummAouzwAGbQPlApHpn8zWmtnwkZHWKPIGrKFDjU48/gA35hDyosCH6G0crLkD5MA DTSqTZrsHnEnDUC6FpVbffEji/uDTytVF8H7uDR9rzsUOEGZI2CQmv7IitOIY0uZQ+EJbzFRoI8Iz zX7TITsw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCfip-0005FL-C7; Fri, 13 Mar 2020 08:31:11 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 0BEC330275A; Fri, 13 Mar 2020 09:31:08 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id E7C162BA3D056; Fri, 13 Mar 2020 09:31:07 +0100 (CET) Date: Fri, 13 Mar 2020 09:31:07 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: Tetsuo Handa , Dmitry Vyukov , Jiri Slaby , Greg Kroah-Hartman , Andrew Morton , Matthew Garrett , Andi Kleen , "Theodore Y . Ts'o" , Alexander Viro , Petr Mladek , Sergey Senozhatsky , Arnd Bergmann , Linus Torvalds , LKML Subject: Re: [PATCH v2] Add kernel config option for fuzz testing. Message-ID: <20200313083107.GV12561@hirez.programming.kicks-ass.net> References: <20200307135822.3894-1-penguin-kernel@I-love.SAKURA.ne.jp> <6f2e27de-c820-7de3-447d-cd9f7c650add@suse.com> <20200308065258.GE3983392@kroah.com> <3e9f47f7-a6c1-7cec-a84f-e621ae5426be@suse.com> <20200311101115.53139149@gandalf.local.home> <7e0d2bbf-71c2-395c-9a42-d3d6d3ee4fa4@i-love.sakura.ne.jp> <20200312182935.70ed6516@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200312182935.70ed6516@gandalf.local.home> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2020 at 06:29:35PM -0400, Steven Rostedt wrote: > > @@ -705,10 +706,12 @@ static void lockdep_print_held_locks(struct task_struct *p) > > * It's not reliable to print a task's held locks if it's not sleeping > > * and it's not the current task. > > */ > > - if (p->state == TASK_RUNNING && p != current) > > - return; > > + unreliable = p->state == TASK_RUNNING && p != current; > > for (i = 0; i < depth; i++) { > > - printk(" #%d: ", i); > > + if (unreliable) > > + printk(" #%d?: ", i); > > + else > > + printk(" #%d: ", i); > > Have you tried submitting this? Has Peter nacked it? It has definite UaF potential... do we have a boot parameter that signals the willingness to trade safetly for more debug output? Over all, the risk of this going *bang* is quite low I think.