From patchwork Fri Mar 26 05:55:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12165793 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 4BB75C433E8 for ; Fri, 26 Mar 2021 05:55:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D045361A27 for ; Fri, 26 Mar 2021 05:55:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D045361A27 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EB2CD6B0070; Fri, 26 Mar 2021 01:55:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DDA136B0072; Fri, 26 Mar 2021 01:55:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BDED66B0071; Fri, 26 Mar 2021 01:55:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0183.hostedemail.com [216.40.44.183]) by kanga.kvack.org (Postfix) with ESMTP id 9590D6B0072 for ; Fri, 26 Mar 2021 01:55:30 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 3D241A74A for ; Fri, 26 Mar 2021 05:55:30 +0000 (UTC) X-FDA: 77960963220.23.22E26EE Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf12.hostedemail.com (Postfix) with ESMTP id 392D2E7 for ; Fri, 26 Mar 2021 05:55:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=JEh94IdPKg4fhtB9SOsbpDDy3Am/p1W6hXBzhIzAAUc=; b=0slIpg67Q1Mk/vAlwR3Sx7Qyz7 PBDdIzvkQX9CBam20i18nxawsoeE/F2h8tw7kfz9pIGcxlpCHd5rxwRsuS6pIxvz+DycvCtqKDsXV M+l1nAtZplQ7jQFReBRg/yg99GRTmWVuZFfk7HiqC1NQNxfpWmtTZE9dkmFT5971euIsavKfvCKX1 lHizI0ooC6UZy/QUlDoDG1Stk4mNm9eWeGowpZaFB6vD5X6Cpy8eSToaZdBXDGNx7f0Kv43APIXaa 9Vd/ZyHIPUSxA/N7mEFGrq7zC9IVJU/udWrL34R5TvRPNb1efi/+hqxnjTcarK4SkkT8T4/S8YSGE EVcCfqgg==; Received: from [2001:4bb8:191:f692:97ff:1e47:aee2:c7e5] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lPfR8-005AHl-04; Fri, 26 Mar 2021 05:55:10 +0000 From: Christoph Hellwig To: Andrew Morton , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi Cc: Chris Wilson , Daniel Vetter , Peter Zijlstra , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH 1/4] mm: add remap_pfn_range_notrack Date: Fri, 26 Mar 2021 06:55:02 +0100 Message-Id: <20210326055505.1424432-2-hch@lst.de> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210326055505.1424432-1-hch@lst.de> References: <20210326055505.1424432-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Stat-Signature: ojkysf7j1w54otcq5qn36s33nnbzr77d X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 392D2E7 Received-SPF: none (bombadil.srs.infradead.org>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=bombadil.infradead.org; client-ip=198.137.202.133 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616738127-9251 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Add a version of remap_pfn_range that does not call track_pfn_range. This will be used to fix horrible abuses of VM internals in the i915 driver. Signed-off-by: Christoph Hellwig --- include/linux/mm.h | 2 ++ mm/memory.c | 51 ++++++++++++++++++++++++++++------------------ 2 files changed, 33 insertions(+), 20 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 64a71bf2053674..70a6160d729ded 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2709,6 +2709,8 @@ unsigned long change_prot_numa(struct vm_area_struct *vma, struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr); int remap_pfn_range(struct vm_area_struct *, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t); +int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, unsigned long size, pgprot_t prot); int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *); int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr, struct page **pages, unsigned long *num); diff --git a/mm/memory.c b/mm/memory.c index 5efa07fb6cdc18..997cda24c4a0be 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2260,26 +2260,17 @@ static inline int remap_p4d_range(struct mm_struct *mm, pgd_t *pgd, return 0; } -/** - * remap_pfn_range - remap kernel memory to userspace - * @vma: user vma to map to - * @addr: target page aligned user address to start at - * @pfn: page frame number of kernel physical memory address - * @size: size of mapping area - * @prot: page protection flags for this mapping - * - * Note: this is only safe if the mm semaphore is held when called. - * - * Return: %0 on success, negative error code otherwise. +/* + * Variant of remap_pfn_range that does not call track_pfn_remap. The caller + * must have pre-validated the caching bits of the pgprot_t. */ -int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, - unsigned long pfn, unsigned long size, pgprot_t prot) +int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, unsigned long size, pgprot_t prot) { pgd_t *pgd; unsigned long next; unsigned long end = addr + PAGE_ALIGN(size); struct mm_struct *mm = vma->vm_mm; - unsigned long remap_pfn = pfn; int err; if (WARN_ON_ONCE(!PAGE_ALIGNED(addr))) @@ -2309,10 +2300,6 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, vma->vm_pgoff = pfn; } - err = track_pfn_remap(vma, &prot, remap_pfn, addr, PAGE_ALIGN(size)); - if (err) - return -EINVAL; - vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; BUG_ON(addr >= end); @@ -2324,12 +2311,36 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, err = remap_p4d_range(mm, pgd, addr, next, pfn + (addr >> PAGE_SHIFT), prot); if (err) - break; + return err; } while (pgd++, addr = next, addr != end); + return 0; +} + +/** + * remap_pfn_range - remap kernel memory to userspace + * @vma: user vma to map to + * @addr: target page aligned user address to start at + * @pfn: page frame number of kernel physical memory address + * @size: size of mapping area + * @prot: page protection flags for this mapping + * + * Note: this is only safe if the mm semaphore is held when called. + * + * Return: %0 on success, negative error code otherwise. + */ +int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, unsigned long size, pgprot_t prot) +{ + int err; + + err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); if (err) - untrack_pfn(vma, remap_pfn, PAGE_ALIGN(size)); + return -EINVAL; + err = remap_pfn_range_notrack(vma, addr, pfn, size, prot); + if (err) + untrack_pfn(vma, pfn, PAGE_ALIGN(size)); return err; } EXPORT_SYMBOL(remap_pfn_range);