From mboxrd@z Thu Jan 1 00:00:00 1970 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 23193C433DB for ; Fri, 22 Jan 2021 18:28:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB64923AAC for ; Fri, 22 Jan 2021 18:28:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729577AbhAVS2i (ORCPT ); Fri, 22 Jan 2021 13:28:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:39060 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728561AbhAVOWy (ORCPT ); Fri, 22 Jan 2021 09:22:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AB64823B75; Fri, 22 Jan 2021 14:16:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611325011; bh=cVXMJvY5hJuBfENHnD5krYolc/OGDjdSaxeJg4eN1JA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TL+Aru9HjVaPUXPi6dB4Lat4emlwdVsXnkTThIiM4X7lZcC3wepULtZmuLtFUYTw7 FxsPIgLhXkIHwBu0X1USHe36cq5/D/5cBrttpcxEAaBexTTPz98bgH5ADfRsNAksxc P80gn9kGkeZj5oQ8aRKL3U4iO2e7fu4HMX1guCr8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Juergen Gross , Andrew Cooper Subject: [PATCH 5.4 03/33] xen/privcmd: allow fetching resource sizes Date: Fri, 22 Jan 2021 15:12:19 +0100 Message-Id: <20210122135733.712747023@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135733.565501039@linuxfoundation.org> References: <20210122135733.565501039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -724,14 +724,15 @@ 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))) @@ -741,6 +742,22 @@ 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); + } + down_write(&mm->mmap_sem); vma = find_vma(mm, kdata.addr); @@ -775,10 +792,6 @@ 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);