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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 72AC8C3F68F for ; Wed, 15 Jan 2020 11:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 52A9A24671 for ; Wed, 15 Jan 2020 11:09:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729809AbgAOLJy (ORCPT ); Wed, 15 Jan 2020 06:09:54 -0500 Received: from mx2.suse.de ([195.135.220.15]:55544 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbgAOLJy (ORCPT ); Wed, 15 Jan 2020 06:09:54 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id BAB13AC81; Wed, 15 Jan 2020 11:09:51 +0000 (UTC) Subject: Re: [PATCH v1 1/4] kasan: introduce set_pmd_early_shadow() To: Sergey Dyasli Cc: xen-devel@lists.xen.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Boris Ostrovsky , Stefano Stabellini , George Dunlap , Ross Lagerwall , Andrew Morton References: <20200108152100.7630-1-sergey.dyasli@citrix.com> <20200108152100.7630-2-sergey.dyasli@citrix.com> <96c2414e-91fb-5a28-44bc-e30d2daabec5@citrix.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <6f643816-a7dc-f3bb-d521-b6ac104918d6@suse.com> Date: Wed, 15 Jan 2020 12:09:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <96c2414e-91fb-5a28-44bc-e30d2daabec5@citrix.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15.01.20 11:54, Sergey Dyasli wrote: > Hi Juergen, > > On 08/01/2020 15:20, Sergey Dyasli wrote: >> It is incorrect to call pmd_populate_kernel() multiple times for the >> same page table. Xen notices it during kasan_populate_early_shadow(): >> >> (XEN) mm.c:3222:d155v0 mfn 3704b already pinned >> >> This happens for kasan_early_shadow_pte when USE_SPLIT_PTE_PTLOCKS is >> enabled. Fix this by introducing set_pmd_early_shadow() which calls >> pmd_populate_kernel() only once and uses set_pmd() afterwards. >> >> Signed-off-by: Sergey Dyasli > > Looks like the plan to use set_pmd() directly has failed: it's an > arch-specific function and can't be used in arch-independent code > (as kbuild test robot has proven). > > Do you see any way out of this other than disabling SPLIT_PTE_PTLOCKS > for PV KASAN? Change set_pmd_early_shadow() like the following: #ifdef CONFIG_XEN_PV static inline void set_pmd_early_shadow(pmd_t *pmd, pte_t *early_shadow) { static bool pmd_populated = false; if (likely(pmd_populated)) { set_pmd(pmd, __pmd(__pa(early_shadow) | _PAGE_TABLE)); } else { pmd_populate_kernel(&init_mm, pmd, early_shadow); pmd_populated = true; } } #else static inline void set_pmd_early_shadow(pmd_t *pmd, pte_t *early_shadow) { pmd_populate_kernel(&init_mm, pmd, early_shadow); } #endif ... and move it to include/xen/xen-ops.h and call it with lm_alias(kasan_early_shadow_pte) as the second parameter. Juergen 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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 42050C33CB1 for ; Wed, 15 Jan 2020 11:10:24 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1BF70222C3 for ; Wed, 15 Jan 2020 11:10:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BF70222C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1irgYl-0007UW-6N; Wed, 15 Jan 2020 11:10:03 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1irgYj-0007KA-OQ for xen-devel@lists.xen.org; Wed, 15 Jan 2020 11:10:01 +0000 X-Inumbo-ID: 8dcc8566-3787-11ea-ac27-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 8dcc8566-3787-11ea-ac27-bc764e2007e4; Wed, 15 Jan 2020 11:09:53 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id BAB13AC81; Wed, 15 Jan 2020 11:09:51 +0000 (UTC) To: Sergey Dyasli References: <20200108152100.7630-1-sergey.dyasli@citrix.com> <20200108152100.7630-2-sergey.dyasli@citrix.com> <96c2414e-91fb-5a28-44bc-e30d2daabec5@citrix.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <6f643816-a7dc-f3bb-d521-b6ac104918d6@suse.com> Date: Wed, 15 Jan 2020 12:09:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <96c2414e-91fb-5a28-44bc-e30d2daabec5@citrix.com> Content-Language: en-US Subject: Re: [Xen-devel] [PATCH v1 1/4] kasan: introduce set_pmd_early_shadow() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Ross Lagerwall , George Dunlap , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, xen-devel@lists.xen.org, linux-mm@kvack.org, Alexander Potapenko , Andrey Ryabinin , Boris Ostrovsky , Andrew Morton , Dmitry Vyukov Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" T24gMTUuMDEuMjAgMTE6NTQsIFNlcmdleSBEeWFzbGkgd3JvdGU6Cj4gSGkgSnVlcmdlbiwKPiAK PiBPbiAwOC8wMS8yMDIwIDE1OjIwLCBTZXJnZXkgRHlhc2xpIHdyb3RlOgo+PiBJdCBpcyBpbmNv cnJlY3QgdG8gY2FsbCBwbWRfcG9wdWxhdGVfa2VybmVsKCkgbXVsdGlwbGUgdGltZXMgZm9yIHRo ZQo+PiBzYW1lIHBhZ2UgdGFibGUuIFhlbiBub3RpY2VzIGl0IGR1cmluZyBrYXNhbl9wb3B1bGF0 ZV9lYXJseV9zaGFkb3coKToKPj4KPj4gICAgICAoWEVOKSBtbS5jOjMyMjI6ZDE1NXYwIG1mbiAz NzA0YiBhbHJlYWR5IHBpbm5lZAo+Pgo+PiBUaGlzIGhhcHBlbnMgZm9yIGthc2FuX2Vhcmx5X3No YWRvd19wdGUgd2hlbiBVU0VfU1BMSVRfUFRFX1BUTE9DS1MgaXMKPj4gZW5hYmxlZC4gRml4IHRo aXMgYnkgaW50cm9kdWNpbmcgc2V0X3BtZF9lYXJseV9zaGFkb3coKSB3aGljaCBjYWxscwo+PiBw bWRfcG9wdWxhdGVfa2VybmVsKCkgb25seSBvbmNlIGFuZCB1c2VzIHNldF9wbWQoKSBhZnRlcndh cmRzLgo+Pgo+PiBTaWduZWQtb2ZmLWJ5OiBTZXJnZXkgRHlhc2xpIDxzZXJnZXkuZHlhc2xpQGNp dHJpeC5jb20+Cj4gCj4gTG9va3MgbGlrZSB0aGUgcGxhbiB0byB1c2Ugc2V0X3BtZCgpIGRpcmVj dGx5IGhhcyBmYWlsZWQ6IGl0J3MgYW4KPiBhcmNoLXNwZWNpZmljIGZ1bmN0aW9uIGFuZCBjYW4n dCBiZSB1c2VkIGluIGFyY2gtaW5kZXBlbmRlbnQgY29kZQo+IChhcyBrYnVpbGQgdGVzdCByb2Jv dCBoYXMgcHJvdmVuKS4KPiAKPiBEbyB5b3Ugc2VlIGFueSB3YXkgb3V0IG9mIHRoaXMgb3RoZXIg dGhhbiBkaXNhYmxpbmcgU1BMSVRfUFRFX1BUTE9DS1MKPiBmb3IgUFYgS0FTQU4/CgpDaGFuZ2Ug c2V0X3BtZF9lYXJseV9zaGFkb3coKSBsaWtlIHRoZSBmb2xsb3dpbmc6CgojaWZkZWYgQ09ORklH X1hFTl9QVgpzdGF0aWMgaW5saW5lIHZvaWQgc2V0X3BtZF9lYXJseV9zaGFkb3cocG1kX3QgKnBt ZCwgcHRlX3QgKmVhcmx5X3NoYWRvdykKewoJc3RhdGljIGJvb2wgcG1kX3BvcHVsYXRlZCA9IGZh bHNlOwoKCWlmIChsaWtlbHkocG1kX3BvcHVsYXRlZCkpIHsKCQlzZXRfcG1kKHBtZCwgX19wbWQo X19wYShlYXJseV9zaGFkb3cpIHwgX1BBR0VfVEFCTEUpKTsKCX0gZWxzZSB7CgkJcG1kX3BvcHVs YXRlX2tlcm5lbCgmaW5pdF9tbSwgcG1kLCBlYXJseV9zaGFkb3cpOwoJCXBtZF9wb3B1bGF0ZWQg PSB0cnVlOwoJfQp9CiNlbHNlCnN0YXRpYyBpbmxpbmUgdm9pZCBzZXRfcG1kX2Vhcmx5X3NoYWRv dyhwbWRfdCAqcG1kLCBwdGVfdCAqZWFybHlfc2hhZG93KQp7CglwbWRfcG9wdWxhdGVfa2VybmVs KCZpbml0X21tLCBwbWQsIGVhcmx5X3NoYWRvdyk7Cn0KI2VuZGlmCgouLi4gYW5kIG1vdmUgaXQg dG8gaW5jbHVkZS94ZW4veGVuLW9wcy5oIGFuZCBjYWxsIGl0IHdpdGgKbG1fYWxpYXMoa2FzYW5f ZWFybHlfc2hhZG93X3B0ZSkgYXMgdGhlIHNlY29uZCBwYXJhbWV0ZXIuCgoKSnVlcmdlbgoKX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVsIG1h aWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0cy54 ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA==