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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 B0D42C433E1 for ; Fri, 21 Aug 2020 08:50:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7CB2F208DB for ; Fri, 21 Aug 2020 08:50:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CB2F208DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 908C68D0030; Fri, 21 Aug 2020 04:50:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 780678D0005; Fri, 21 Aug 2020 04:50:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5F7508D0030; Fri, 21 Aug 2020 04:50:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0060.hostedemail.com [216.40.44.60]) by kanga.kvack.org (Postfix) with ESMTP id 3EF588D0005 for ; Fri, 21 Aug 2020 04:50:43 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 06E4D181AEF10 for ; Fri, 21 Aug 2020 08:50:43 +0000 (UTC) X-FDA: 77173955166.24.chin00_5307d1b27037 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id CDB621A4A7 for ; Fri, 21 Aug 2020 08:50:42 +0000 (UTC) X-HE-Tag: chin00_5307d1b27037 X-Filterd-Recvd-Size: 3905 Received: from fireflyinternet.com (unknown [77.68.26.236]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Fri, 21 Aug 2020 08:50:42 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 22195097-1500050 for multiple; Fri, 21 Aug 2020 09:50:14 +0100 From: Chris Wilson To: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org Cc: linux-mm@kvack.org, Chris Wilson , Pavel Machek , Andrew Morton , Joerg Roedel , Linus Torvalds , Dave Airlie , Joonas Lahtinen , Rodrigo Vivi , David Vrabel , stable@vger.kernel.org Subject: [PATCH 1/4] mm: Export flush_vm_area() to sync the PTEs upon construction Date: Fri, 21 Aug 2020 09:50:08 +0100 Message-Id: <20200821085011.28878-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Rspamd-Queue-Id: CDB621A4A7 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 Content-Transfer-Encoding: quoted-printable 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: The alloc_vm_area() is another method for drivers to vmap/map_kernel_range that uses apply_to_page_range() rather than the direct vmalloc walkers. This is missing the page table modification tracking, and the ability to synchronize the PTE updates afterwards. Provide flush_vm_area() for the users of alloc_vm_area() that assumes the worst and ensures that the page directories are correctly flushed upon construction. The impact is most pronounced on x86_32 due to the delayed set_pmd(). Reported-by: Pavel Machek References: 2ba3e6947aed ("mm/vmalloc: track which page-table levels were= modified") References: 86cf69f1d893 ("x86/mm/32: implement arch_sync_kernel_mappings= ()") Signed-off-by: Chris Wilson Cc: Andrew Morton Cc: Joerg Roedel Cc: Linus Torvalds Cc: Dave Airlie Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: Pavel Machek Cc: David Vrabel Cc: # v5.8+ --- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 16 ++++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 0221f852a7e1..a253b27df0ac 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -204,6 +204,7 @@ static inline void set_vm_flush_reset_perms(void *add= r) =20 /* Allocate/destroy a 'vmalloc' VM area. */ extern struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes); +extern void flush_vm_area(struct vm_struct *area); extern void free_vm_area(struct vm_struct *area); =20 /* for /dev/kmem */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index b482d240f9a2..c41934486031 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3078,6 +3078,22 @@ struct vm_struct *alloc_vm_area(size_t size, pte_t= **ptes) } EXPORT_SYMBOL_GPL(alloc_vm_area); =20 +void flush_vm_area(struct vm_struct *area) +{ + unsigned long addr =3D (unsigned long)area->addr; + + /* apply_to_page_range() doesn't track the damage, assume the worst */ + if (ARCH_PAGE_TABLE_SYNC_MASK & (PGTBL_PTE_MODIFIED | + PGTBL_PMD_MODIFIED | + PGTBL_PUD_MODIFIED | + PGTBL_P4D_MODIFIED | + PGTBL_PGD_MODIFIED)) + arch_sync_kernel_mappings(addr, addr + area->size); + + flush_cache_vmap(addr, area->size); +} +EXPORT_SYMBOL_GPL(flush_vm_area); + void free_vm_area(struct vm_struct *area) { struct vm_struct *ret; --=20 2.20.1