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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43757C433FE for ; Mon, 3 Oct 2022 23:53:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229861AbiJCXxS (ORCPT ); Mon, 3 Oct 2022 19:53:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229495AbiJCXxN (ORCPT ); Mon, 3 Oct 2022 19:53:13 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9335523BE3; Mon, 3 Oct 2022 16:53:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664841192; x=1696377192; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=XsbQqB1kOV5HDsgsc4ONdzxsJU1pLr3Pc/WAWDj/ozo=; b=nRPEqYmVaE0MM0Ksv7Q55Z32YUCsu5AGy1PuPLcRRvM2Tb4fKqko0j5z QFrHXgJmhWTCNSMvXl0vIGEz2csaqMX/vf/k/ecibZeexVXa3Wd8/63r0 69o7gYYP+9c8A2NjUfot0OpL6tpGRuWNCFSxtUzV12Q3V427Itpsa2PjI YNeESS3tOpPqiZm1Qq7ThsviLl0SOnZreH8vwo/8Ec9chI7s0Pmm31jzI 3WXwUsG1vRVNEGLtM86odAq5L2ICxBom2CpOY1zrBHfGhDSEU50icqWho b5n2q1+QO5Y5e8mbkPMwFwJHAc2fZao1WqqP8CRf6XMTie7+asLWpF2kL g==; X-IronPort-AV: E=McAfee;i="6500,9779,10489"; a="366887311" X-IronPort-AV: E=Sophos;i="5.93,366,1654585200"; d="scan'208";a="366887311" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Oct 2022 16:53:11 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10489"; a="749189186" X-IronPort-AV: E=Sophos;i="5.93,366,1654585200"; d="scan'208";a="749189186" Received: from bandrei-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.252.37.219]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Oct 2022 16:53:03 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 319D8104CE4; Tue, 4 Oct 2022 02:53:00 +0300 (+03) Date: Tue, 4 Oct 2022 02:53:00 +0300 From: "Kirill A . Shutemov" 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 , Borislav Petkov , 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" , Weijiang Yang , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, Yu-cheng Yu Subject: Re: [PATCH v2 16/39] x86/mm: Update maybe_mkwrite() for shadow stack Message-ID: <20221003235300.zkf6lfemd7kyl47z@box.shutemov.name> References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-17-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220929222936.14584-17-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 29, 2022 at 03:29:13PM -0700, Rick Edgecombe wrote: > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 8cd413c5a329..fef14ab3abcb 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -981,13 +981,25 @@ void free_compound_page(struct page *page); > * servicing faults for write access. In the normal case, do always want > * pte_mkwrite. But get_user_pages can cause write faults for mappings > * that do not have writing enabled, when used by access_process_vm. > + * > + * If a vma is shadow stack (a type of writable memory), mark the pte shadow > + * stack. > */ > +#ifndef maybe_mkwrite > static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) > { > - if (likely(vma->vm_flags & VM_WRITE)) > + if (!(vma->vm_flags & VM_WRITE)) > + goto out; > + > + if (vma->vm_flags & VM_SHADOW_STACK) > + pte = pte_mkwrite_shstk(pte); > + else > pte = pte_mkwrite(pte); > + > +out: > return pte; > } > +#endif Maybe take opportunity to move it to ? It is really not a place for the helper. -- Kiryl Shutsemau / Kirill A. Shutemov