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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,URIBL_SBL,URIBL_SBL_A, USER_AGENT_GIT autolearn=ham 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 ECC0DC46464 for ; Tue, 14 Aug 2018 17:47:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE8A72150F for ; Tue, 14 Aug 2018 17:47:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE8A72150F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391180AbeHNUf2 (ORCPT ); Tue, 14 Aug 2018 16:35:28 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60914 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390379AbeHNUf2 (ORCPT ); Tue, 14 Aug 2018 16:35:28 -0400 Received: from localhost (unknown [194.244.16.108]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id C71A540B; Tue, 14 Aug 2018 17:47:14 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , Kees Cook , Andrew Morton , Andy Lutomirski , Borislav Petkov , Dave Hansen , Fenghua Yu , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Peter Zijlstra , Quentin Casasnovas , Thomas Gleixner , Ingo Molnar , Guenter Roeck Subject: [PATCH 4.4 30/43] mm: Add vm_insert_pfn_prot() Date: Tue, 14 Aug 2018 19:18:06 +0200 Message-Id: <20180814171519.080414264@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180814171517.014285600@linuxfoundation.org> References: <20180814171517.014285600@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Lutomirski commit 1745cbc5d0dee0749a6bc0ea8e872c5db0074061 upstream The x86 vvar vma contains pages with differing cacheability flags. x86 currently implements this by manually inserting all the ptes using (io_)remap_pfn_range when the vma is set up. x86 wants to move to using .fault with VM_FAULT_NOPAGE to set up the mappings as needed. The correct API to use to insert a pfn in .fault is vm_insert_pfn(), but vm_insert_pfn() can't override the vma's cache mode, and the HPET page in particular needs to be uncached despite the fact that the rest of the VMA is cached. Add vm_insert_pfn_prot() to support varying cacheability within the same non-COW VMA in a more sane manner. x86 could alternatively use multiple VMAs, but that's messy, would break CRIU, and would create unnecessary VMAs that would waste memory. Signed-off-by: Andy Lutomirski Reviewed-by: Kees Cook Acked-by: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Quentin Casasnovas Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/d2938d1eb37be7a5e4f86182db646551f11e45aa.1451446564.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- include/linux/mm.h | 2 ++ mm/memory.c | 25 +++++++++++++++++++++++-- 2 files changed, 25 insertions(+), 2 deletions(-) --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2083,6 +2083,8 @@ int remap_pfn_range(struct vm_area_struc int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *); int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn); +int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, pgprot_t pgprot); int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn); int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len); --- a/mm/memory.c +++ b/mm/memory.c @@ -1605,8 +1605,29 @@ out: int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn) { + return vm_insert_pfn_prot(vma, addr, pfn, vma->vm_page_prot); +} +EXPORT_SYMBOL(vm_insert_pfn); + +/** + * vm_insert_pfn_prot - insert single pfn into user vma with specified pgprot + * @vma: user vma to map to + * @addr: target user address of this page + * @pfn: source kernel pfn + * @pgprot: pgprot flags for the inserted page + * + * This is exactly like vm_insert_pfn, except that it allows drivers to + * to override pgprot on a per-page basis. + * + * This only makes sense for IO mappings, and it makes no sense for + * cow mappings. In general, using multiple vmas is preferable; + * vm_insert_pfn_prot should only be used if using multiple VMAs is + * impractical. + */ +int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, pgprot_t pgprot) +{ int ret; - pgprot_t pgprot = vma->vm_page_prot; /* * Technically, architectures with pte_special can avoid all these * restrictions (same for remap_pfn_range). However we would like @@ -1628,7 +1649,7 @@ int vm_insert_pfn(struct vm_area_struct return ret; } -EXPORT_SYMBOL(vm_insert_pfn); +EXPORT_SYMBOL(vm_insert_pfn_prot); int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn)