From nobody Sun Feb 8 19:54:49 2026 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 6F2A2C88CBB for ; Tue, 13 Jun 2023 00:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239256AbjFMAPu (ORCPT ); Mon, 12 Jun 2023 20:15:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233336AbjFMAOY (ORCPT ); Mon, 12 Jun 2023 20:14:24 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17AA41FD4; Mon, 12 Jun 2023 17:12:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1686615176; x=1718151176; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=c7sunRbrNdSwt/1KmOuIzzKZkXv73NcNzDYIVaoBldo=; b=G03JU2S0Evi/fePKI8tofmFf6jCfbNuseYNk3pBFLsEjtODG0wjoLGX+ fTtSibEDt9OAP17er1I4Y2zOUV+gLWqXTiu7hsS6hUTYyhxkDSadT8Ihk C5CDBUZgCNPaY5h5CR/sbJg/4LKePeZkxee12wEJJxmjKh4tipSR+a9Qc w5tc+YhEQtoNcTjqPXbqzwshaVvGDWwcJzqPt9OrfXmTvLLO3tyz384MH 2E5LkLl5e2e07zNSx8KSt4z1kHIfUHdPl8zbXgCZdRIuKlsGxnubCYOtY P3ghlZM2+r1GM7YyFY84GurNIdlWtTMvT2smfRg87Qwe8bKcd9xoMsz4a w==; X-IronPort-AV: E=McAfee;i="6600,9927,10739"; a="361557144" X-IronPort-AV: E=Sophos;i="6.00,238,1681196400"; d="scan'208";a="361557144" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jun 2023 17:12:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10739"; a="835671052" X-IronPort-AV: E=Sophos;i="6.00,238,1681196400"; d="scan'208";a="835671052" Received: from almeisch-mobl1.amr.corp.intel.com (HELO rpedgeco-desk4.amr.corp.intel.com) ([10.209.42.242]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jun 2023 17:12:25 -0700 From: Rick Edgecombe To: 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 , 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, szabolcs.nagy@arm.com, torvalds@linux-foundation.org, broonie@kernel.org Cc: rick.p.edgecombe@intel.com, Pengfei Xu Subject: [PATCH v9 21/42] x86/mm: Teach pte_mkwrite() about stack memory Date: Mon, 12 Jun 2023 17:10:47 -0700 Message-Id: <20230613001108.3040476-22-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230613001108.3040476-1-rick.p.edgecombe@intel.com> References: <20230613001108.3040476-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If a VMA has the VM_SHADOW_STACK flag, it is shadow stack memory. So when it is made writable with pte_mkwrite(), it should create shadow stack memory, not conventionally writable memory. Now that all the places where shadow stack memory might be created pass a VMA into pte_mkwrite(), it can know when it should do this. So make pte_mkwrite() create shadow stack memory when the VMA has the VM_SHADOW_STACK flag. Do the same thing for pmd_mkwrite(). This requires referencing VM_SHADOW_STACK in these functions, which are currently defined in pgtable.h, however mm.h (where VM_SHADOW_STACK is located) can't be pulled in without causing problems for files that reference pgtable.h. So also move pte/pmd_mkwrite() into pgtable.c, where they can safely reference VM_SHADOW_STACK. Signed-off-by: Rick Edgecombe Reviewed-by: Borislav Petkov (AMD) Reviewed-by: Kees Cook Acked-by: Mike Rapoport (IBM) Acked-by: Deepak Gupta Tested-by: Pengfei Xu Tested-by: John Allen Tested-by: Kees Cook --- arch/x86/mm/pgtable.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 101e721d74aa..c4b222d3b1b4 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -883,6 +883,9 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) =20 pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma) { + if (vma->vm_flags & VM_SHADOW_STACK) + return pte_mkwrite_shstk(pte); + pte =3D pte_mkwrite_novma(pte); =20 return pte_clear_saveddirty(pte); @@ -890,6 +893,9 @@ pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma) =20 pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) { + if (vma->vm_flags & VM_SHADOW_STACK) + return pmd_mkwrite_shstk(pmd); + pmd =3D pmd_mkwrite_novma(pmd); =20 return pmd_clear_saveddirty(pmd); --=20 2.34.1