From patchwork Fri Aug 21 08:50:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11728647 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E960C722 for ; Fri, 21 Aug 2020 08:50:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C0D4D208DB for ; Fri, 21 Aug 2020 08:50:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0D4D208DB 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) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 780678D0005; Fri, 21 Aug 2020 04:50:43 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org 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-Original-To: linux-mm@kvack.org 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-Spam-Summary: 1,0,0,09a66b3b1e8616c1,d41d8cd98f00b204,chris@chris-wilson.co.uk,,RULES_HIT:41:355:379:541:800:960:966:973:988:989:1260:1311:1314:1345:1431:1437:1515:1534:1542:1711:1730:1747:1777:1792:2196:2199:2393:2559:2562:3138:3139:3140:3141:3142:3353:3865:3866:3867:3868:3871:3874:4250:4321:4385:4605:5007:6261:6742:7901:8603:10004:11026:11473:11658:11914:12043:12296:12297:12438:12555:12679:12895:12986:13161:13221:13229:13894:14096:14181:14394:14571:14721:21080:21451:21627:30054:30064:30070,0,RBL:77.68.26.236:@chris-wilson.co.uk:.lbl8.mailshell.net-64.201.201.201 62.8.15.100;04yg738ch6sbhwxochui5u7g8d86dope864fn3hg5duj54eo88gmoi31czkyxid.xuooom6j8zje98e3fq4hjqbhosiim3p4tgyj19dmq11eg631ytpdywcq9g9ipoz.r-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none 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 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 *addr) /* 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); /* 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); +void flush_vm_area(struct vm_struct *area) +{ + unsigned long addr = (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;