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=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 C0508C2D0C2 for ; Tue, 31 Dec 2019 12:13:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9264A20409 for ; Tue, 31 Dec 2019 12:13:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="L1M0d2Mf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727106AbfLaMNm (ORCPT ); Tue, 31 Dec 2019 07:13:42 -0500 Received: from mail.skyhub.de ([5.9.137.197]:43534 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726334AbfLaMNm (ORCPT ); Tue, 31 Dec 2019 07:13:42 -0500 Received: from zn.tnic (p4FED3FEE.dip0.t-ipconnect.de [79.237.63.238]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id C266E1EC0216; Tue, 31 Dec 2019 13:13:40 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1577794421; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=oR2xbj0U/pPGMoJ8gZOuKTnC6YknArbdAxhM7IvzOgI=; b=L1M0d2MfDvXwB06BInNWbNrRyxXJ4p8eDWXOOC1n/RXs6mpQ2saXsgVesChtYtCn60jG7+ SBCfc9UtbWk0c6apV5LWzFHPhERhSr3VoPf1lCSNVyNciCmnC8tHSycqfsu4pL/EZgPGlQ 28R/sA9gg+yXZLyaBXZGDBcyGdJlvSI= Date: Tue, 31 Dec 2019 13:11:21 +0100 From: Borislav Petkov To: Jann Horn Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, Andrey Konovalov , Andy Lutomirski , Sean Christopherson Subject: Re: [PATCH v7 3/4] x86/dumpstack: Introduce die_addr() for die() with #GP fault address Message-ID: <20191231121121.GA13549@zn.tnic> References: <20191218231150.12139-1-jannh@google.com> <20191218231150.12139-3-jannh@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191218231150.12139-3-jannh@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 19, 2019 at 12:11:49AM +0100, Jann Horn wrote: > diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c > index c8b4ae6aed5b..4c691bb9e0d9 100644 > --- a/arch/x86/kernel/traps.c > +++ b/arch/x86/kernel/traps.c > @@ -621,7 +621,10 @@ do_general_protection(struct pt_regs *regs, long error_code) > "maybe for address", > gp_addr); > - die(desc, regs, error_code); I've added here: /* * KASAN is interested only in the non-canonical case, clear it * otherwise. */ > + if (hint != GP_NON_CANONICAL) > + gp_addr = 0; otherwise you have: if (hint != GP_NO_HINT) ... if (hint != GP_NON_CANONICAL) ... which is kinda confusing at a first glance and one has to follow the code into die_addr() to figure out the usage of the address argument. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette