From nobody Mon Feb 9 04:31:48 2026 Delivered-To: importer@patchew.org Received-SPF: none (zohomail.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=none (zohomail.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail(p=none dis=none) header.from=intel.com ARC-Seal: i=1; a=rsa-sha256; t=1577722382; cv=none; d=zohomail.com; s=zohoarc; b=VngbU1i59I3ZixOOp6ZDKGNH99lMHLRe8veOViYIrjnuCEjTXFHNc3W2G2chYoLPDn0jGIpjVTKDOeDHellHR1L7LdnWYZsGijoMpbK3jJknQxC3Ll5A0u7hmAuBM39bkTkah2vWSOjHVSumQ8dsY8qsuCLi7Uz+EawKMHPFkew= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1577722382; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=jP5VsZITJWRmUGwV2qknusATfYxlUTawbUrYUe+rTZU=; b=hmBO3Bts43kzhQ10K6CNIENqLqp4uOsSSrQXVj6Weff6PlmfwirXOW4CDDLeys63lLm4k8UajDi0gokvoVv4acon8l7jT+Sisgu2HxmejV8GIieHhu4XdlA7bTZFzWdddyxoB2ZM162XcD0mxiyoeYAoGwbmhi/BqdKrj7t83LA= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=none (zohomail.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1577722382189798.3114678093102; Mon, 30 Dec 2019 08:13:02 -0800 (PST) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ilxej-0002RQ-07; Mon, 30 Dec 2019 16:12:33 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ilxeg-0002PY-U1 for xen-devel@lists.xenproject.org; Mon, 30 Dec 2019 16:12:30 +0000 Received: from mga14.intel.com (unknown [192.55.52.115]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 1c8738b6-2b1f-11ea-a914-bc764e2007e4; Mon, 30 Dec 2019 16:12:02 +0000 (UTC) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Dec 2019 08:12:00 -0800 Received: from tlengyel-mobl2.amr.corp.intel.com (HELO localhost.localdomain) ([10.254.94.206]) by orsmga003.jf.intel.com with ESMTP; 30 Dec 2019 08:12:00 -0800 X-Inumbo-ID: 1c8738b6-2b1f-11ea-a914-bc764e2007e4 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,375,1571727600"; d="scan'208";a="221167363" From: Tamas K Lengyel To: xen-devel@lists.xenproject.org Date: Mon, 30 Dec 2019 08:11:38 -0800 Message-Id: <0f92c0ee2861775e682fd6e89202c80315ff2ac3.1577721845.git.tamas.lengyel@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Subject: [Xen-devel] [PATCH v3 14/18] x86/mem_sharing: check page type count earlier 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: Tamas K Lengyel , Tamas K Lengyel , Wei Liu , George Dunlap , Andrew Cooper , Jan Beulich , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Signed-off-by: Tamas K Lengyel --- xen/arch/x86/mm/mem_sharing.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c index baa3e35ded..ecbe40545d 100644 --- a/xen/arch/x86/mm/mem_sharing.c +++ b/xen/arch/x86/mm/mem_sharing.c @@ -652,19 +652,18 @@ static int page_make_sharable(struct domain *d, return -EBUSY; } =20 - /* Change page type and count atomically */ - if ( !get_page_and_type(page, d, PGT_shared_page) ) + /* Check if page is already typed and bail early if it is */ + if ( (page->u.inuse.type_info & PGT_count_mask) !=3D 1 ) { spin_unlock(&d->page_alloc_lock); - return -EINVAL; + return -EEXIST; } =20 - /* Check it wasn't already sharable and undo if it was */ - if ( (page->u.inuse.type_info & PGT_count_mask) !=3D 1 ) + /* Change page type and count atomically */ + if ( !get_page_and_type(page, d, PGT_shared_page) ) { spin_unlock(&d->page_alloc_lock); - put_page_and_type(page); - return -EEXIST; + return -EINVAL; } =20 /* --=20 2.20.1 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel