From patchwork Mon Jan 18 11:33:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 366042 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=-18.8 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, URIBL_BLOCKED, USER_AGENT_GIT 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 C57BEC4332B for ; Mon, 18 Jan 2021 14:31:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9615D22B40 for ; Mon, 18 Jan 2021 14:31:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392968AbhARObZ (ORCPT ); Mon, 18 Jan 2021 09:31:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:38112 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389763AbhARLnE (ORCPT ); Mon, 18 Jan 2021 06:43:04 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id ECA7222C9E; Mon, 18 Jan 2021 11:42:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610970163; bh=ZaxmYAtPovvFtipAxAYfImaO2vyGuNvCQP6Vs2/QdZY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ewaf+X+bttecWHAcOEO8QjR5V7kJr8g2rDKmo4zwhA7wHHEG6RdZqFGN+YrtvMe/O qPt0QDhe/nJtpcLCVy2WZJ9qqhtPZQLUFMT0wviGix1Xi4mukLTeX5RAVEwOCSzHhL du76mQEWKsKlD2womm8TSq5l9OVU4+esvKY0E3YU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?utf-8?q?Roger_Pau_Monn=C3=A9?= , Juergen Gross , Andrew Cooper Subject: [PATCH 5.10 036/152] xen/privcmd: allow fetching resource sizes Date: Mon, 18 Jan 2021 12:33:31 +0100 Message-Id: <20210118113354.512931546@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210118113352.764293297@linuxfoundation.org> References: <20210118113352.764293297@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Roger Pau Monne commit ef3a575baf53571dc405ee4028e26f50856898e7 upstream. Allow issuing an IOCTL_PRIVCMD_MMAP_RESOURCE ioctl with num = 0 and addr = 0 in order to fetch the size of a specific resource. Add a shortcut to the default map resource path, since fetching the size requires no address to be passed in, and thus no VMA to setup. This is missing from the initial implementation, and causes issues when mapping resources that don't have fixed or known sizes. Signed-off-by: Roger Pau Monné Reviewed-by: Juergen Gross Tested-by: Andrew Cooper Cc: stable@vger.kernel.org # >= 4.18 Link: https://lore.kernel.org/r/20210112115358.23346-1-roger.pau@citrix.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/xen/privcmd.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -717,14 +717,15 @@ static long privcmd_ioctl_restrict(struc return 0; } -static long privcmd_ioctl_mmap_resource(struct file *file, void __user *udata) +static long privcmd_ioctl_mmap_resource(struct file *file, + struct privcmd_mmap_resource __user *udata) { struct privcmd_data *data = file->private_data; struct mm_struct *mm = current->mm; struct vm_area_struct *vma; struct privcmd_mmap_resource kdata; xen_pfn_t *pfns = NULL; - struct xen_mem_acquire_resource xdata; + struct xen_mem_acquire_resource xdata = { }; int rc; if (copy_from_user(&kdata, udata, sizeof(kdata))) @@ -734,6 +735,22 @@ static long privcmd_ioctl_mmap_resource( if (data->domid != DOMID_INVALID && data->domid != kdata.dom) return -EPERM; + /* Both fields must be set or unset */ + if (!!kdata.addr != !!kdata.num) + return -EINVAL; + + xdata.domid = kdata.dom; + xdata.type = kdata.type; + xdata.id = kdata.id; + + if (!kdata.addr && !kdata.num) { + /* Query the size of the resource. */ + rc = HYPERVISOR_memory_op(XENMEM_acquire_resource, &xdata); + if (rc) + return rc; + return __put_user(xdata.nr_frames, &udata->num); + } + mmap_write_lock(mm); vma = find_vma(mm, kdata.addr); @@ -768,10 +785,6 @@ static long privcmd_ioctl_mmap_resource( } else vma->vm_private_data = PRIV_VMA_LOCKED; - memset(&xdata, 0, sizeof(xdata)); - xdata.domid = kdata.dom; - xdata.type = kdata.type; - xdata.id = kdata.id; xdata.frame = kdata.idx; xdata.nr_frames = kdata.num; set_xen_guest_handle(xdata.frame_list, pfns);