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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48519C4332F for ; Tue, 15 Nov 2022 22:27:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238588AbiKOW1L (ORCPT ); Tue, 15 Nov 2022 17:27:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232203AbiKOW0m (ORCPT ); Tue, 15 Nov 2022 17:26:42 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48781317D2; Tue, 15 Nov 2022 14:26:29 -0800 (PST) Date: Tue, 15 Nov 2022 22:26:26 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1668551187; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=pn5UtiqnRGWlXM480Esc6q28LEpVXsJC04ec2EQZjWU=; b=dtbHKtn0ZpWT4r3/2guQbR+S0Pi5H1Y7QsXcdviel3KIB8ztVDhG7Z7CG7tF/QmtPKjJBk SNZJbVrIlK9PLeo/7eWJw3jRRh653onuqOYNvmjuEdzNjh7WGa3X87RPDwlX4gwqyncGTd kbKhjErGHOLpmmydwS/7Ft2XWorr8ctVpjN4bZwmlI/NeU5zSplJc2DL2be9LTaxl5t5jS gZ3jLgDD/eaGd64XinGGcJbbPv80BPyZX/6x2x3Rv+Yv5KxIMV4IjJ5l0nhBvGsINS/FtJ PZqaFyRzxtbU29GxbGFODyh64VTFuc1+dvt3+Gel7/CEOrMeDrBHnlOdJkQMkw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1668551187; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=pn5UtiqnRGWlXM480Esc6q28LEpVXsJC04ec2EQZjWU=; b=+tz4oZcJX9zq+tt9ZADPCtiyGR5gNQPdsORtpjPQ4naRXs3Con3PpsdHROYuTMPiMMDiut ceUowSkgJ7HurvDQ== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/mm] x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias() Cc: kernel test robot , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <166855118670.4906.4131361261876319025.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/mm branch of tip: Commit-ID: 127960a05548ea699a95791669e8112552eb2452 Gitweb: https://git.kernel.org/tip/127960a05548ea699a95791669e8112552eb2452 Author: Peter Zijlstra AuthorDate: Thu, 10 Nov 2022 13:33:57 +01:00 Committer: Peter Zijlstra CommitterDate: Tue, 15 Nov 2022 22:29:58 +01:00 x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias() There is a cludge in change_page_attr_set_clr() that inhibits propagating NX changes to the aliases (directmap and highmap) -- this is a cludge twofold: - it also inhibits the primary checks in __change_page_attr(); - it hard depends on single bit changes. The introduction of set_memory_rox() triggered this last issue for clearing both _PAGE_RW and _PAGE_NX. Explicitly ignore _PAGE_NX in cpa_process_alias() instead. Fixes: b38994948567 ("x86/mm: Implement native set_memory_rox()") Reported-by: kernel test robot Debugged-by: Dave Hansen Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221110125544.594991716%40infradead.org --- arch/x86/mm/pat/set_memory.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 4943f6c..beef774 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -1669,6 +1669,12 @@ static int cpa_process_alias(struct cpa_data *cpa) alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); alias_cpa.curpage = 0; + /* Directmap always has NX set, do not modify. */ + if (__supported_pte_mask & _PAGE_NX) { + alias_cpa.mask_clr.pgprot &= ~_PAGE_NX; + alias_cpa.mask_set.pgprot &= ~_PAGE_NX; + } + cpa->force_flush_all = 1; ret = __change_page_attr_set_clr(&alias_cpa, 0); @@ -1691,6 +1697,15 @@ static int cpa_process_alias(struct cpa_data *cpa) alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); alias_cpa.curpage = 0; + /* + * [_text, _brk_end) also covers data, do not modify NX except + * in cases where the highmap is the primary target. + */ + if (__supported_pte_mask & _PAGE_NX) { + alias_cpa.mask_clr.pgprot &= ~_PAGE_NX; + alias_cpa.mask_set.pgprot &= ~_PAGE_NX; + } + cpa->force_flush_all = 1; /* * The high mapping range is imprecise, so ignore the @@ -1709,6 +1724,12 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) unsigned long rempages = numpages; int ret = 0; + /* + * No changes, easy! + */ + if (!(pgprot_val(cpa->mask_set) | pgprot_val(cpa->mask_clr))) + return ret; + while (rempages) { /* * Store the remaining nr of pages for the large page @@ -1755,7 +1776,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, struct page **pages) { struct cpa_data cpa; - int ret, cache, checkalias; + int ret, cache; memset(&cpa, 0, sizeof(cpa)); @@ -1805,10 +1826,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, cpa.curpage = 0; cpa.force_split = force_split; - /* No alias checking for _NX bit modifications */ - checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX; - - ret = __change_page_attr_set_clr(&cpa, checkalias); + ret = __change_page_attr_set_clr(&cpa, 1); /* * Check whether we really changed something: