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=-11.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 31640C76195 for ; Mon, 22 Jul 2019 08:23:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 080ED2229A for ; Mon, 22 Jul 2019 08:23:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="d5YgKXtn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728399AbfGVIXv (ORCPT ); Mon, 22 Jul 2019 04:23:51 -0400 Received: from terminus.zytor.com ([198.137.202.136]:50289 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726571AbfGVIXt (ORCPT ); Mon, 22 Jul 2019 04:23:49 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x6M8Nat33738684 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Mon, 22 Jul 2019 01:23:36 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x6M8Nat33738684 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019071901; t=1563783816; bh=UnylQ2uIKauxwDTMbH02wxKZYqGV7EC4IvB+0V+WZ5g=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=d5YgKXtn7tTEDdQmzXUyng6+FfttbaRGYKhDd8pH3VA+ECBYQcsIG7VSMb8yfFK6u QH8295Z0VAojeqrqEEu8xRo/hjlrbAzT872cbrvqgMjlfgSTOZwivQbFcuDxJs4OPB w5A4rL3/qLuP9wlbcpbkUFAF92/RnhYUbp0i3OzMW8Rqyu6m6RtnHP3DqsJPxSZsqa F6rsSMejUKNvzUCny2/iC6otKDtIIK+cTi8Ry287qPOIbcUJ2S/1PTR3EUa1K0fNd2 9mwNqg7iOgqp04xhEBS7QIyi/XuksWqkXWMUcjSiHOM5G1lyLZKPx8X0aU8+6rv7Az gq5jTYVSHCc4Q== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x6M8NZZO3738680; Mon, 22 Jul 2019 01:23:35 -0700 Date: Mon, 22 Jul 2019 01:23:35 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Joerg Roedel Message-ID: Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, jroedel@suse.de, dave.hansen@linux.intel.com, mingo@kernel.org, tglx@linutronix.de Reply-To: dave.hansen@linux.intel.com, tglx@linutronix.de, mingo@kernel.org, jroedel@suse.de, linux-kernel@vger.kernel.org, hpa@zytor.com In-Reply-To: <20190719184652.11391-4-joro@8bytes.org> References: <20190719184652.11391-4-joro@8bytes.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy() Git-Commit-ID: 3f8fd02b1bf1d7ba964485a56f2f4b53ae88c167 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 3f8fd02b1bf1d7ba964485a56f2f4b53ae88c167 Gitweb: https://git.kernel.org/tip/3f8fd02b1bf1d7ba964485a56f2f4b53ae88c167 Author: Joerg Roedel AuthorDate: Fri, 19 Jul 2019 20:46:52 +0200 Committer: Thomas Gleixner CommitDate: Mon, 22 Jul 2019 10:18:30 +0200 mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy() On x86-32 with PTI enabled, parts of the kernel page-tables are not shared between processes. This can cause mappings in the vmalloc/ioremap area to persist in some page-tables after the region is unmapped and released. When the region is re-used the processes with the old mappings do not fault in the new mappings but still access the old ones. This causes undefined behavior, in reality often data corruption, kernel oopses and panics and even spontaneous reboots. Fix this problem by activly syncing unmaps in the vmalloc/ioremap area to all page-tables in the system before the regions can be re-used. References: https://bugzilla.suse.com/show_bug.cgi?id=1118689 Fixes: 5d72b4fba40ef ('x86, mm: support huge I/O mapping capability I/F') Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Reviewed-by: Dave Hansen Link: https://lkml.kernel.org/r/20190719184652.11391-4-joro@8bytes.org --- mm/vmalloc.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4fa8d84599b0..e0fc963acc41 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1258,6 +1258,12 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) if (unlikely(valist == NULL)) return false; + /* + * First make sure the mappings are removed from all page-tables + * before they are freed. + */ + vmalloc_sync_all(); + /* * TODO: to calculate a flush range without looping. * The list can be up to lazy_max_pages() elements. @@ -3038,6 +3044,9 @@ EXPORT_SYMBOL(remap_vmalloc_range); /* * Implement a stub for vmalloc_sync_all() if the architecture chose not to * have one. + * + * The purpose of this function is to make sure the vmalloc area + * mappings are identical in all page-tables in the system. */ void __weak vmalloc_sync_all(void) {