Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9C2FC61DA3 for ; Fri, 24 Feb 2023 12:20:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229977AbjBXMUe (ORCPT ); Fri, 24 Feb 2023 07:20:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229911AbjBXMUb (ORCPT ); Fri, 24 Feb 2023 07:20:31 -0500 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 861875D45C; Fri, 24 Feb 2023 04:20:30 -0800 (PST) Received: from zn.tnic (p5de8e9fe.dip0.t-ipconnect.de [93.232.233.254]) (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 138CB1EC0723; Fri, 24 Feb 2023 13:20:29 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1677241229; 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=3wlwiK1nNffOcPqzViDroCDgIPey06MUV3oYwrGZbKI=; b=r1POMqdP/hXKk7k7IpdK0dI2u/Hy0OFeiILxv284CCrDQW0R1mSntbXCdxhRuxVklJnZLf 0twGNtT0NIrIeG8EErDShXCb0vKAS95g1CejT82cU3t8Ud0c1DXLE6SJHDd07zqEeXrUMK RS9BahVgyen34o3TrlrChBMlA6tXDa4= Date: Fri, 24 Feb 2023 13:20:19 +0100 From: Borislav Petkov To: Rick Edgecombe Cc: x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , Weijiang Yang , "Kirill A . Shutemov" , John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, akpm@linux-foundation.org, Andrew.Cooper3@citrix.com, christina.schimpe@intel.com, david@redhat.com, debug@rivosinc.com Subject: Re: [PATCH v6 28/41] x86: Introduce userspace API for shadow stack Message-ID: References: <20230218211433.26859-1-rick.p.edgecombe@intel.com> <20230218211433.26859-29-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230218211433.26859-29-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 18, 2023 at 01:14:20PM -0800, Rick Edgecombe wrote: > diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h > index 500b96e71f18..b2b3b7200b2d 100644 > --- a/arch/x86/include/uapi/asm/prctl.h > +++ b/arch/x86/include/uapi/asm/prctl.h > @@ -20,4 +20,10 @@ > #define ARCH_MAP_VDSO_32 0x2002 > #define ARCH_MAP_VDSO_64 0x2003 > > +/* Don't use 0x3001-0x3004 because of old glibcs */ So where is this all new interface to userspace programs documented? Do we have an agreement with all the involved parties that this is how we're going to support shadow stacks and that this is what userspace should do? I'd like to avoid one more fiasco with glibc etc here... Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette