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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5A7E8C04AB3 for ; Mon, 27 May 2019 21:11:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B3EA20815 for ; Mon, 27 May 2019 21:11:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727368AbfE0VLh (ORCPT ); Mon, 27 May 2019 17:11:37 -0400 Received: from mga04.intel.com ([192.55.52.120]:23653 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726839AbfE0VLZ (ORCPT ); Mon, 27 May 2019 17:11:25 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 May 2019 14:11:24 -0700 X-ExtLoop1: 1 Received: from rpedgeco-mobl.amr.corp.intel.com (HELO localhost.intel.com) ([10.251.0.167]) by orsmga008.jf.intel.com with ESMTP; 27 May 2019 14:11:24 -0700 From: Rick Edgecombe To: linux-kernel@vger.kernel.org, peterz@infradead.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, luto@kernel.org Cc: dave.hansen@intel.com, namit@vmware.com, Rick Edgecombe , Meelis Roos , "David S. Miller" , Borislav Petkov , Ingo Molnar Subject: [PATCH v5 1/2] vmalloc: Fix calculation of direct map addr range Date: Mon, 27 May 2019 14:10:57 -0700 Message-Id: <20190527211058.2729-2-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190527211058.2729-1-rick.p.edgecombe@intel.com> References: <20190527211058.2729-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The calculation of the direct map address range to flush was wrong. This could cause the RO direct map alias to not get flushed. Today this shouldn't be a problem because this flush is only needed on x86 right now and the spurious fault handler will fix cached RO->RW translations. In the future though, it could cause the permissions to remain RO in the TLB for the direct map alias, and then the page would return from the page allocator to some other component as RO and cause a crash. So fix fix the address range calculation so the flush will include the direct map range. Fixes: 868b104d7379 ("mm/vmalloc: Add flag for freeing of special permsissions") Cc: Meelis Roos Cc: Peter Zijlstra Cc: "David S. Miller" Cc: Dave Hansen Cc: Borislav Petkov Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Nadav Amit Signed-off-by: Rick Edgecombe --- mm/vmalloc.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 233af6936c93..3ede9c064477 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2123,7 +2123,6 @@ static inline void set_area_direct_map(const struct vm_struct *area, /* Handle removing and resetting vm mappings related to the vm_struct. */ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) { - unsigned long addr = (unsigned long)area->addr; unsigned long start = ULONG_MAX, end = 0; int flush_reset = area->flags & VM_FLUSH_RESET_PERMS; int i; @@ -2135,8 +2134,8 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) * execute permissions, without leaving a RW+X window. */ if (flush_reset && !IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { - set_memory_nx(addr, area->nr_pages); - set_memory_rw(addr, area->nr_pages); + set_memory_nx((unsigned long)area->addr, area->nr_pages); + set_memory_rw((unsigned long)area->addr, area->nr_pages); } remove_vm_area(area->addr); @@ -2160,9 +2159,11 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) * the vm_unmap_aliases() flush includes the direct map. */ for (i = 0; i < area->nr_pages; i++) { - if (page_address(area->pages[i])) { + unsigned long addr = + (unsigned long)page_address(area->pages[i]); + if (addr) { start = min(addr, start); - end = max(addr, end); + end = max(addr + PAGE_SIZE, end); } } -- 2.20.1