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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 DF92BC433E0 for ; Mon, 10 Aug 2020 14:06:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAE7C20678 for ; Mon, 10 Aug 2020 14:06:59 +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="UamQ/jqM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726978AbgHJOG6 (ORCPT ); Mon, 10 Aug 2020 10:06:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726845AbgHJOG6 (ORCPT ); Mon, 10 Aug 2020 10:06:58 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25C24C061756 for ; Mon, 10 Aug 2020 07:06:58 -0700 (PDT) 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=0NkcUhh2BgxISPZreSijRxme2NhNix1+tFt4ONKujyE=; b=UamQ/jqMujk+F8HamiNl6Rxl36 P5XIgyW2bMiXe7mXZ3ty7215KWppEzzOB+SMCtBGUaXjPYoSl7i3bprOIdiXw5mwNt6RebEkj0QtP ET2BcmGpZpaaPQxxv19Z8LZBqsSd6MgXHYwFCT3gc1rkxmxAbojJoFfwLtM8aKqitQi8AXGkKA1jd tGUO9eWMKyXNmp1S6gNEGTGuAfQlIk91E+5l0Q4ePobrJLyEOxbdW7iaA4jfmIH/4aEVWkbo8hpoT eL64na/ZbDfXDzvoaq16VPLNWNH45XyEOrsY/K7t5Yk+4WyBSxqEMAY3YLckSXAVjXcyg+j3/Sh7V w2sV5mLQ==; 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 1k58Rt-0005F0-Sm; Mon, 10 Aug 2020 14:06:50 +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 7618430015A; Mon, 10 Aug 2020 16:06:48 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 618082B2C802B; Mon, 10 Aug 2020 16:06:48 +0200 (CEST) Date: Mon, 10 Aug 2020 16:06:48 +0200 From: peterz@infradead.org To: Marco Elver Cc: "Paul E. McKenney" , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Mark Rutland , Dmitry Vyukov , Alexander Potapenko , Andrey Konovalov , kasan-dev , LKML , syzbot Subject: Re: [PATCH] kcsan: Treat runtime as NMI-like with interrupt tracing Message-ID: <20200810140648.GZ2674@hirez.programming.kicks-ass.net> References: <20200807090031.3506555-1-elver@google.com> <20200807170618.GW4295@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 10, 2020 at 10:07:44AM +0200, Marco Elver wrote: > On Fri, 7 Aug 2020 at 19:06, Paul E. McKenney wrote: > > On Fri, Aug 07, 2020 at 11:00:31AM +0200, Marco Elver wrote: > > > Since KCSAN instrumentation is everywhere, we need to treat the hooks > > > NMI-like for interrupt tracing. In order to present an as 'normal' as > > > possible context to the code called by KCSAN when reporting errors, we > > > need to update the IRQ-tracing state. > > > > > > Tested: Several runs through kcsan-test with different configuration > > > (PROVE_LOCKING on/off), as well as hours of syzbot testing with the > > > original config that caught the problem (without CONFIG_PARAVIRT=y, > > > which appears to cause IRQ state tracking inconsistencies even when > > > KCSAN remains off, see Link). > > > > > > Link: https://lkml.kernel.org/r/0000000000007d3b2d05ac1c303e@google.com > > > Fixes: 248591f5d257 ("kcsan: Make KCSAN compatible with new IRQ state tracking") > > > Reported-by: syzbot+8db9e1ecde74e590a657@syzkaller.appspotmail.com > > > Co-developed-by: Peter Zijlstra (Intel) > > Peter, if you're fine with it, I think we'll require your > Signed-off-by (since Co-developed-by). Sure: Signed-off-by: Peter Zijlstra (Intel)