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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 17B5CC433ED for ; Sat, 10 Apr 2021 09:29:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E18D0611BF for ; Sat, 10 Apr 2021 09:29:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229591AbhDJJaI (ORCPT ); Sat, 10 Apr 2021 05:30:08 -0400 Received: from mail.skyhub.de ([5.9.137.197]:37160 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbhDJJaH (ORCPT ); Sat, 10 Apr 2021 05:30:07 -0400 Received: from zn.tnic (p200300ec2f1aea004ff424aef8172112.dip0.t-ipconnect.de [IPv6:2003:ec:2f1a:ea00:4ff4:24ae:f817:2112]) (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 243AB1EC0409; Sat, 10 Apr 2021 11:29:52 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1618046992; 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=U4fOVgCu+Cc3JD0fk9iTK0StzoBFsYk6BLIrkX0M9Mk=; b=DRP6H5Ya6IuI83rk+l8ifJgdtETmDKwOsMtW/uVOTSKMmoq2JlNAflXx9ngr3q1hYBwnKo Otg746xtSkovC47rbD3PERQsxbGqzbsmyQ/zEdn+F8RrBZtspuxrsUYofvIb8SM6xRVtGJ GvB0pOIrbUR/pw+mHGHW1CoVzKbqFO0= Date: Sat, 10 Apr 2021 11:29:51 +0200 From: Borislav Petkov To: "Yu, Yu-cheng" 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 , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Haitao Huang Subject: Re: [PATCH v24 04/30] x86/cpufeatures: Introduce X86_FEATURE_CET and setup functions Message-ID: <20210410092951.GA21691@zn.tnic> References: <20210401221104.31584-1-yu-cheng.yu@intel.com> <20210401221104.31584-5-yu-cheng.yu@intel.com> <20210409101214.GC15567@zn.tnic> <20210409171408.GG15567@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Fri, Apr 09, 2021 at 04:14:09PM -0700, Yu, Yu-cheng wrote: > > @@ -53,6 +55,8 @@ static short xsave_cpuid_features[] __initdata = { > > X86_FEATURE_INTEL_PT, > > X86_FEATURE_PKU, > > X86_FEATURE_ENQCMD, > > + X86_FEATURE_CET, /* XFEATURE_CET_USER */ > > + X86_FEATURE_CET, /* XFEATURE_CET_KERNEL */ > > > > or what is the piece which becomes simpler? > > Yes, this is it. Those should be X86_FEATURE_SHSTK no? > Signals, arch_prctl, and ELF header are three places that need to depend on > either shadow stack or IBT is configured. To remain simple, we can make all > three depend on CONFIG_X86_SHADOW_STACK, and in Kconfig, make CONFIG_X86_IBT > depend on CONFIG_X86_SHADOW_STACK. Without shadow stack, IBT itself is not > as useful anyway. Makes sense to me. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette