From patchwork Thu Nov 10 12:52:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 18116 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp131632wru; Thu, 10 Nov 2022 05:01:28 -0800 (PST) X-Google-Smtp-Source: AA0mqf5JuYhy6zT27BkPlQv3ESqm1ArUl7JC7d0YX0OM250T/zz0O1zLM8ZJaFV2wFB2BVMYrfya X-Received: by 2002:a17:906:3c1:b0:7ae:6e4b:6c06 with SMTP id c1-20020a17090603c100b007ae6e4b6c06mr15060745eja.70.1668085288667; Thu, 10 Nov 2022 05:01:28 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1668085288; cv=none; d=google.com; s=arc-20160816; b=yKq6Ca431fGQOdGNGsZj1BKtsTzsDsVOtFy4X4FJLqtAkssc4QZYhDvgPBn6c07cVH bvE9KFj5dAV5IMgqBFMcKIPdOl9vjuk0jdROWZH/sM6LAOx4hQFg8UbVncCHbV4xvbCj gVg1aftaXVxJQl2LxH1Caxm7KHN+fiHf5fDayzchX2YOYxtJ5zXJM1A+Ly9HLO2uhjp3 x0fxuOkB9d6kyw6qzCk1djW3sP6POJ7DiI63PKQc/YOdoTKonSxdBIprY/gvYvYIX19t P1x40DHY3Tt5nRs2zVbD+RARiAgjvA2+sH6HbQTeeo4WQ6D/NXfaHEDSJL91Vl4r4P8F AJzw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:references:subject:cc:to:from:date :user-agent:message-id:dkim-signature; bh=aPpH2DkMTrxhIpV4/nr31HwzcYRECeuZHF/THcTg9IQ=; b=wA251GQhjZEPnV8xtsVgVFcXsw5Btkv07rdx+BXasA8Q+HI4hLvnYtvcUTTp2hGoTV oUovr+2AagUIWbvxBkzxP5J4f59TuI/d6YQS9g7O1VOtqqsXpWCGeQGbPcO1HCiVu0po 02oORI1oV54RgVVOpXLYt5tGyAJAqTLQlY5eNoMquOAnW+AmCGKtJKCZ48Ssc7827UVN 7DS+Z9hamLIp+nUxHXpg4d/bP2BAXi1WoOHRgz7653Za/XKOKgWNuSE208sVK79qgSom zi9Ja5r/kpsxpJtpwsTrGcGtTj7zbzwxL409DauIkBteYim0RyGfzZhMdcJRMlMk7ja6 6kGQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=desiato.20200630 header.b=bOrHaMwg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id dr7-20020a170907720700b0078e27f2ef4bsi21363903ejc.956.2022.11.10.05.00.54; Thu, 10 Nov 2022 05:01:28 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=desiato.20200630 header.b=bOrHaMwg; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229938AbiKJM6v (ORCPT + 99 others); Thu, 10 Nov 2022 07:58:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229607AbiKJM6p (ORCPT ); Thu, 10 Nov 2022 07:58:45 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DF4370193 for ; Thu, 10 Nov 2022 04:58:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=aPpH2DkMTrxhIpV4/nr31HwzcYRECeuZHF/THcTg9IQ=; b=bOrHaMwgqQMBbaFqDrfYG5Hxae T/Nqo44VJCmxtdGCuA1GZz7PuqLSbypNVFCoIj/yLx2D5hIiVO57+QtCOEn/p2auvvRoDvl0/5EzZ Yodhh4+8gmn1z6tGkQsJPRi01Hf0KxkgAS2RXSeEEayJEOelh3C/TOaCYGqjoIrYNzUGMVKYaFhv5 dDVQPE3Sz9JIrKb++4X8p+Y0AAZMQhJc+lMOKvc+RxpmoulwxAL45ylxpZGN9817SYJc1D5EIWIs9 3gX0vbXgAcB9b9a1wHU2UrHXymxBPJMiezENM+A1jWh3V3vg29Nuzir/mUvM4Le5gQBEVTis8OnpU XKAryR9w==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1ot78X-00AHCf-9x; Thu, 10 Nov 2022 12:58:30 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id CCCF8300487; Thu, 10 Nov 2022 13:58:27 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id AA85D2B97262B; Thu, 10 Nov 2022 13:58:27 +0100 (CET) Message-ID: <20221110125544.594991716@infradead.org> User-Agent: quilt/0.66 Date: Thu, 10 Nov 2022 13:52:56 +0100 From: Peter Zijlstra To: x86@kernel.org, dave.hansen@intel.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, torvalds@linux-foundation.org, oliver.sang@intel.com Subject: [PATCH 3/4] x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias() References: <20221110125253.240704966@infradead.org> MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1749114199562719799?= X-GMAIL-MSGID: =?utf-8?q?1749114199562719799?= 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) Acked-by: Dave Hansen --- arch/x86/mm/pat/set_memory.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -1663,6 +1663,12 @@ static int cpa_process_alias(struct 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); @@ -1685,6 +1691,15 @@ static int cpa_process_alias(struct 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 @@ -1703,6 +1718,12 @@ static int __change_page_attr_set_clr(st 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 @@ -1749,7 +1770,7 @@ static int change_page_attr_set_clr(unsi struct page **pages) { struct cpa_data cpa; - int ret, cache, checkalias; + int ret, cache; memset(&cpa, 0, sizeof(cpa)); @@ -1799,10 +1820,7 @@ static int change_page_attr_set_clr(unsi 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: