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 C837EC4338F for ; Mon, 16 Aug 2021 17:03:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC66A60F36 for ; Mon, 16 Aug 2021 17:03:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233087AbhHPREG (ORCPT ); Mon, 16 Aug 2021 13:04:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231799AbhHPRDz (ORCPT ); Mon, 16 Aug 2021 13:03:55 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43432C0613CF; Mon, 16 Aug 2021 10:03:20 -0700 (PDT) Received: from zn.tnic (p200300ec2f08b500a9c2327ac48af0d7.dip0.t-ipconnect.de [IPv6:2003:ec:2f08:b500:a9c2:327a:c48a:f0d7]) (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 045F31EC0516; Mon, 16 Aug 2021 19:03:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1629133395; 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=cdjFAwQRlWFZrMh487IcfeXjtfV+kPYJk4xdQyxxwG8=; b=NUhUMN3z0T5t1Vvly3U2phQ+JRBo7JbQ8+kHQYZTrWatPMnvakMbGX9OCYIvzB8DUgNiZt 3rFOUKsALV6KjJSsyxTWCiPKl9M3JpH0v9SzbA6vMHgawtmQG+yebfxl2m+mllhj+FPIrh dQjTxAjZbSBwv9k/ww48hnbm+fPbw5M= Date: Mon, 16 Aug 2021 19:03:54 +0200 From: Borislav Petkov To: Yu-cheng Yu 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 , Rick P Edgecombe , "Kirill A . Shutemov" Subject: Re: [PATCH v28 16/32] x86/mm: Update maybe_mkwrite() for shadow stack Message-ID: References: <20210722205219.7934-1-yu-cheng.yu@intel.com> <20210722205219.7934-17-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210722205219.7934-17-yu-cheng.yu@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 22, 2021 at 01:52:03PM -0700, Yu-cheng Yu wrote: > diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c > index 3364fe62b903..ba449d12ec32 100644 > --- a/arch/x86/mm/pgtable.c > +++ b/arch/x86/mm/pgtable.c > @@ -610,6 +610,26 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma, > } > #endif > > +pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) > +{ > + if (likely(vma->vm_flags & VM_WRITE)) > + pte = pte_mkwrite(pte); > + else if (likely(vma->vm_flags & VM_SHADOW_STACK)) > + pte = pte_mkwrite_shstk(pte); > + return pte; > +} > + > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) > +{ > + if (likely(vma->vm_flags & VM_WRITE)) > + pmd = pmd_mkwrite(pmd); > + else if (likely(vma->vm_flags & VM_SHADOW_STACK)) > + pmd = pmd_mkwrite_shstk(pmd); What are all those likely()ies here for? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette