From patchwork Thu Apr 16 15:44:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 11493277 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 887801392 for ; Thu, 16 Apr 2020 15:46:22 +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 6F5B221927 for ; Thu, 16 Apr 2020 15:46:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F5B221927 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass 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 1jP6hH-0005ys-8x; Thu, 16 Apr 2020 15:44:59 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jP6hG-0005yk-4Y for xen-devel@lists.xenproject.org; Thu, 16 Apr 2020 15:44:58 +0000 X-Inumbo-ID: 393736e4-7ff9-11ea-83d8-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 393736e4-7ff9-11ea-83d8-bc764e2007e4; Thu, 16 Apr 2020 15:44:57 +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 30189AB5C; Thu, 16 Apr 2020 15:44:56 +0000 (UTC) Subject: [PATCH 1/6] x86/mem-paging: fold p2m_mem_paging_prep()'s main if()-s From: Jan Beulich To: "xen-devel@lists.xenproject.org" References: <3b7cc69d-709c-570a-716a-c45f6fda181f@suse.com> Message-ID: <44a7d9ce-6c38-89a7-f558-4db220dcb21d@suse.com> Date: Thu, 16 Apr 2020 17:44:55 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <3b7cc69d-709c-570a-716a-c45f6fda181f@suse.com> Content-Language: en-US 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: Andrew Cooper , George Dunlap , Wei Liu , =?utf-8?q?R?= =?utf-8?q?oger_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The condition of the second can be true only if the condition of the first was met; the second half of the condition of the second then also is redundant with an earlier check. Combine them, drop a pointless local variable, and re-flow the affected gdprintk(). Signed-off-by: Jan Beulich --- a/xen/arch/x86/mm/p2m.c +++ b/xen/arch/x86/mm/p2m.c @@ -1808,6 +1808,8 @@ int p2m_mem_paging_prep(struct domain *d /* Allocate a page if the gfn does not have one yet */ if ( !mfn_valid(mfn) ) { + void *guest_map; + /* If the user did not provide a buffer, we disallow */ ret = -EINVAL; if ( unlikely(user_ptr == NULL) ) @@ -1819,22 +1821,16 @@ int p2m_mem_paging_prep(struct domain *d goto out; mfn = page_to_mfn(page); page_extant = 0; - } - - /* If we were given a buffer, now is the time to use it */ - if ( !page_extant && user_ptr ) - { - void *guest_map; - int rc; ASSERT( mfn_valid(mfn) ); guest_map = map_domain_page(mfn); - rc = copy_from_user(guest_map, user_ptr, PAGE_SIZE); + ret = copy_from_user(guest_map, user_ptr, PAGE_SIZE); unmap_domain_page(guest_map); - if ( rc ) + if ( ret ) { - gdprintk(XENLOG_ERR, "Failed to load paging-in gfn %lx domain %u " - "bytes left %d\n", gfn_l, d->domain_id, rc); + gdprintk(XENLOG_ERR, + "Failed to load paging-in gfn %lx Dom%d bytes left %d\n", + gfn_l, d->domain_id, ret); ret = -EFAULT; put_page(page); /* Don't leak pages */ goto out;