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 6DB9AC433E0 for ; Tue, 2 Jun 2020 17:59:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40CC020734 for ; Tue, 2 Jun 2020 17:59:29 +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="h1ZqR31o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726894AbgFBR72 (ORCPT ); Tue, 2 Jun 2020 13:59:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726019AbgFBR71 (ORCPT ); Tue, 2 Jun 2020 13:59:27 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2DCBC05BD1E for ; Tue, 2 Jun 2020 10:59:27 -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=5Y3HKI5svjaEX0i1wQ6y4ya6URar/l/ginxsdDN/q0M=; b=h1ZqR31owc5qrUxjp4IUDlH647 pCZeh/SghJcpPNeBBd7iSBH7IwYPPt/ADioUIUzH3ci0IWOEzelsREAYWXoyKyhRmtl843ukQgliX CJQCO7zQwVJtZqUruWdsWVE2uBJ7fviK6f/D9PYqfKyi04hllBQc8nxxkdrTbjf6fywAS+j+iTEH1 yo3ksjsqR2Ty2nOSK4Vnm6/FuVQZjAa5SiXoPE6bOKzh/xz8sFtN1FfPuyYF4U2+PBGbwMB9HZxhX l5rpVfDGN1LS5nbExEc0npnEaWQY0yAXeBrxO6niAYh4wPDQNOW+SBZEAKkZUf1bIZNkpVB4sjVYd JKSMtMwA==; 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 1jgBBl-0000yt-5m; Tue, 02 Jun 2020 17:59:01 +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 F3B9C3011B2; Tue, 2 Jun 2020 19:58:59 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DECFE202436F2; Tue, 2 Jun 2020 19:58:59 +0200 (CEST) Date: Tue, 2 Jun 2020 19:58:59 +0200 From: Peter Zijlstra To: Marco Elver Cc: Dmitry Vyukov , Thomas Gleixner , syzbot , LKML , syzkaller-bugs , Ingo Molnar , Borislav Petkov , the arch/x86 maintainers , Oleg Nesterov , kasan-dev Subject: Re: PANIC: double fault in fixup_bad_iret Message-ID: <20200602175859.GC2604@hirez.programming.kicks-ass.net> References: <000000000000d2474c05a6c938fe@google.com> <87o8q6n38p.fsf@nanos.tec.linutronix.de> <20200529160711.GC706460@hirez.programming.kicks-ass.net> <20200529171104.GD706518@hirez.programming.kicks-ass.net> <20200602094141.GR706495@hirez.programming.kicks-ass.net> 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 Tue, Jun 02, 2020 at 07:51:40PM +0200, Marco Elver wrote: > We have all attributes except __no_sanitize_coverage. GCC <= 7 has > problems with __always_inline, so we may just have to bump the > required compiler or emit a warning. GCC <= 7 will hard fail the compile with those function attributes. Bumping the min GCC version for KASAN/UBSAN to avoid that might be best. > > > Not sure what the best strategy is to minimize patch conflicts. For > > > now I could send just the patches to add missing definitions. If you'd > > > like me to send all patches (including modifying 'noinstr'), let me > > > know. > > > > If you're going to do patches anyway, might as well do that :-) > > I was stuck on trying to find ways to emulate __no_sanitize_coverage > (with no success), and then agonizing which patches to send in which > sequence. ;-) You made that decision by sending the KCSAN noinstr > series first, so let me respond to that with what I think we can add > for KASAN and UBSAN at least. Excellent, thanks!