From patchwork Thu Jan 14 14:02:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 12019603 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=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 3DE81C4332D for ; Thu, 14 Jan 2021 14:02:45 +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 CFADC23A84 for ; Thu, 14 Jan 2021 14:02:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFADC23A84 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.67040.119329 (Exim 4.92) (envelope-from ) id 1l03Ct-0007N1-PI; Thu, 14 Jan 2021 14:02:35 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 67040.119329; Thu, 14 Jan 2021 14:02:35 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l03Ct-0007Mu-MJ; Thu, 14 Jan 2021 14:02:35 +0000 Received: by outflank-mailman (input) for mailman id 67040; Thu, 14 Jan 2021 14:02:34 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l03Cs-0007Mp-Cq for xen-devel@lists.xenproject.org; Thu, 14 Jan 2021 14:02:34 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 31151c5e-baee-452b-9a55-b0bcee4013f5; Thu, 14 Jan 2021 14:02:32 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id F1FF6ACB0; Thu, 14 Jan 2021 14:02:31 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 31151c5e-baee-452b-9a55-b0bcee4013f5 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1610632952; h=from:from:reply-to: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=2jUhgF0ak9MLvHUH1tdbmCeMP2HyJzmt3uYCQSjCXew=; b=uMC6Ls0Cp8ismuSrU+VTPMTOGNWWnBHt9KVtKFc6+lAzUk2JE5yzBY+1kBptjaoMX8zXCZ IgI5nvJQM3s8tHSYKWQWxrvl6DrlcpafKGCx+4mMWC8F9jbejDNY5NV+6YTvf3p9wbqgji OdhoujhcWmRZWleYTl0Ks0vUMrbaHYM= To: "xen-devel@lists.xenproject.org" Cc: Andrew Cooper , George Dunlap , Ian Jackson , Julien Grall , Stefano Stabellini , Wei Liu From: Jan Beulich Subject: [PATCH] common: don't require use of DOMID_SELF Message-ID: <72c9f0ec-81e3-63f9-2513-46e463642219@suse.com> Date: Thu, 14 Jan 2021 15:02:32 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 Content-Language: en-US It's not overly difficult for a domain to figure out its ID, so requiring the use of DOMID_SELF in a very limited set of places isn't really helpful towards keeping the ID opaque to the guest. Signed-off-by: Jan Beulich --- a/xen/common/grant_table.c +++ b/xen/common/grant_table.c @@ -2776,15 +2776,19 @@ struct gnttab_copy_buf { static int gnttab_copy_lock_domain(domid_t domid, bool is_gref, struct gnttab_copy_buf *buf) { - /* Only DOMID_SELF may reference via frame. */ - if ( domid != DOMID_SELF && !is_gref ) - return GNTST_permission_denied; - buf->domain = rcu_lock_domain_by_any_id(domid); if ( !buf->domain ) return GNTST_bad_domain; + /* Only the local domain may reference via frame. */ + if ( buf->domain != current->domain && !is_gref ) + { + rcu_unlock_domain(buf->domain); + buf->domain = NULL; + return GNTST_permission_denied; + } + buf->ptr.domid = domid; return GNTST_okay; --- a/xen/common/page_alloc.c +++ b/xen/common/page_alloc.c @@ -2566,13 +2566,7 @@ __initcall(register_heap_trigger); struct domain *get_pg_owner(domid_t domid) { - struct domain *pg_owner = NULL, *curr = current->domain; - - if ( unlikely(domid == curr->domain_id) ) - { - gdprintk(XENLOG_WARNING, "Cannot specify itself as foreign domain\n"); - goto out; - } + struct domain *pg_owner; switch ( domid ) { @@ -2590,7 +2584,6 @@ struct domain *get_pg_owner(domid_t domi break; } - out: return pg_owner; }