From nobody Mon Apr 29 11:21:59 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1601362098; cv=none; d=zohomail.com; s=zohoarc; b=c2GCQs8khsbw5N2vStDTPQmlBULFyqyUugvI9tdmjnn37OaogFYSjD+Jjh+oVaGQOpKug26vAYmVzlN7puFa4pi6NYFlmmtnyy9+z8Cu2tjg4ddbrZ3EvH2Eg4nyJVdJzODcc7KfUGooOg+vyhpojdCf6x/N54NaXJv+dp6fTms= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1601362098; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To; bh=3LR+dwaQUZ6SzbID5TihAiEVauXYa30PbUOGjfffUI0=; b=DloxmvXQSgcngKbOOkK3lG3VhnUDEYua1fcEBwX+H4lcsEIDuIEhCYJrMHIpwagtuBMJpeS0gYKRKNYQDIM89rIGamf/w4GHCv6ImISKYqR4jmmPgl1mqWttaMhOqNkNPOkJXHHqkDr4sdd9dRThMjZaIaW7eGVWWNsxxs6FS1o= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1601362098676527.0278900028196; Mon, 28 Sep 2020 23:48:18 -0700 (PDT) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kN9QU-0006wN-RH; Tue, 29 Sep 2020 06:47:50 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kN9QT-0006wI-HW for xen-devel@lists.xenproject.org; Tue, 29 Sep 2020 06:47:49 +0000 Received: from huawei.com (unknown [45.249.212.191]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 093f2dc9-556a-491a-acf9-94b34892d329; Tue, 29 Sep 2020 06:47:40 +0000 (UTC) Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id CE388C25261604B34474; Tue, 29 Sep 2020 14:47:37 +0800 (CST) Received: from huawei.com (10.175.127.227) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Tue, 29 Sep 2020 14:47:28 +0800 X-Inumbo-ID: 093f2dc9-556a-491a-acf9-94b34892d329 From: Jason Yan To: , , , , , , , , CC: Jason Yan Subject: [PATCH] x86/xen: only unlock when USE_SPLIT_PTE_PTLOCKS is true Date: Tue, 29 Sep 2020 14:48:28 +0800 Message-ID: <20200929064828.3606720-1-yanaijie@huawei.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Content-Type: text/plain; charset="utf-8" When USE_SPLIT_PTE_PTLOCKS is false, xen_pte_lock() actually do nothing but returns NULL. So xen_pte_unlock() should not actually unlock. Otherwise a NULL pointer dereference will be triggered. Fixes: 74260714c56d ("xen: lock pte pages while pinning/unpinning") Signed-off-by: Jason Yan --- arch/x86/xen/mmu_pv.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index eda78144c000..c70cbdf5c0fa 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -656,8 +656,10 @@ static spinlock_t *xen_pte_lock(struct page *page, str= uct mm_struct *mm) =20 static void xen_pte_unlock(void *v) { +#if USE_SPLIT_PTE_PTLOCKS spinlock_t *ptl =3D v; spin_unlock(ptl); +#endif } =20 static void xen_do_pin(unsigned level, unsigned long pfn) --=20 2.25.4