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 A8276C6379F for ; Sat, 18 Feb 2023 21:20:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230150AbjBRVUd (ORCPT ); Sat, 18 Feb 2023 16:20:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229836AbjBRVTv (ORCPT ); Sat, 18 Feb 2023 16:19:51 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F72C17177; Sat, 18 Feb 2023 13:17:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676755057; x=1708291057; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=FRX2Zip/lmlZmsFz5KdG4yfHn5/JjBj845luOn8deCo=; b=LxLWhvIUq99wc9yIlNXxwllW1u1pqMUk9nyDEJHTrOTv2txHj6A/2asV dySGPJ+mRt8PmXNVyPGCLqscMxEUVFEESat5UMmZZUGuLg/Y809yveOAC gbaZEtxYj1Dsev6w+Kp8ZRKVntzD9fpk0q/IkpaqoiLX2w2jr0EmqCXMV 0myzWOfcbYM10+Kd7F3dRopiEgkqp+9DGqPqwvGVV+JD/3dw3ULLyAdhC FYrbhy1PAH0hgznC3COSQ+YawWYhq2KVvX9hQW+ttwQThC9JXZqgABl9M IT1bpuV8f1zshNVoQ8HSSRvDel7RYJvI4aopmfP3IPlMrFyOiVHVWhD+T Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10625"; a="418427526" X-IronPort-AV: E=Sophos;i="5.97,309,1669104000"; d="scan'208";a="418427526" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2023 13:16:13 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10625"; a="664241668" X-IronPort-AV: E=Sophos;i="5.97,309,1669104000"; d="scan'208";a="664241668" Received: from adityava-mobl1.amr.corp.intel.com (HELO rpedgeco-desk.amr.corp.intel.com) ([10.209.80.223]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Feb 2023 13:16:12 -0800 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 Cc: rick.p.edgecombe@intel.com Subject: [PATCH v6 20/41] x86/mm: Teach pte_mkwrite() about stack memory Date: Sat, 18 Feb 2023 13:14:12 -0800 Message-Id: <20230218211433.26859-21-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230218211433.26859-1-rick.p.edgecombe@intel.com> References: <20230218211433.26859-1-rick.p.edgecombe@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 pte_mkwrite() takes a VMA, and places where shadow stack memory might be created pass one, pte_mkwrite() 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. Tested-by: Pengfei Xu Signed-off-by: Rick Edgecombe --- v6: - New patch --- arch/x86/include/asm/pgtable.h | 20 ++------------------ arch/x86/mm/pgtable.c | 26 ++++++++++++++++++++++++++ 2 files changed, 28 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 292a3b75d7fa..6b7106457bfb 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -456,15 +456,7 @@ static inline pte_t pte_mkwrite_kernel(pte_t pte) struct vm_area_struct; -static inline pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma) -{ - pte = pte_mkwrite_kernel(pte); - - if (pte_dirty(pte)) - pte = pte_clear_saveddirty(pte); - - return pte; -} +pte_t pte_mkwrite(pte_t pte, struct vm_area_struct *vma); static inline pte_t pte_mkhuge(pte_t pte) { @@ -601,15 +593,7 @@ static inline pmd_t pmd_mkyoung(pmd_t pmd) return pmd_set_flags(pmd, _PAGE_ACCESSED); } -static inline pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) -{ - pmd = pmd_set_flags(pmd, _PAGE_RW); - - if (pmd_dirty(pmd)) - pmd = pmd_clear_saveddirty(pmd); - - return pmd; -} +pmd_t pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); static inline pud_t pud_set_flags(pud_t pud, pudval_t set) { diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index e4f499eb0f29..98856bcc8102 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -880,3 +880,29 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) #endif /* CONFIG_X86_64 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ + +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 = pte_mkwrite_kernel(pte); + + if (pte_dirty(pte)) + pte = pte_clear_saveddirty(pte); + + return pte; +} + +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 = pmd_set_flags(pmd, _PAGE_RW); + + if (pmd_dirty(pmd)) + pmd = pmd_clear_saveddirty(pmd); + + return pmd; +} -- 2.17.1