From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755047AbbJGRVR (ORCPT ); Wed, 7 Oct 2015 13:21:17 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33812 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754933AbbJGRVP (ORCPT ); Wed, 7 Oct 2015 13:21:15 -0400 Date: Wed, 7 Oct 2015 18:21:12 +0100 From: Greg KH To: Vlad Zolotarov Cc: linux-kernel@vger.kernel.org, mst@redhat.com, hjk@hansjkoch.de, corbet@lwn.net, bruce.richardson@intel.com, avi@cloudius-systems.com, gleb@cloudius-systems.com, stephen@networkplumber.org, alexander.duyck@gmail.com Subject: Re: [PATCH v5 1/4] uio: add ioctl support Message-ID: <20151007172112.GC9702@kroah.com> References: <1444151859-10217-1-git-send-email-vladz@cloudius-systems.com> <1444151859-10217-2-git-send-email-vladz@cloudius-systems.com> <20151007084627.GA4270@kroah.com> <5614DDE5.1050100@cloudius-systems.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5614DDE5.1050100@cloudius-systems.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 07, 2015 at 11:55:01AM +0300, Vlad Zolotarov wrote: > > > On 10/07/15 11:46, Greg KH wrote: > >On Tue, Oct 06, 2015 at 08:17:36PM +0300, Vlad Zolotarov wrote: > >>Add the ability for underlying device drivers to register the ioctl > >>commands. This is useful when some interaction with the user space > >>beyond sysfs capabilities is required, e.g. query the interrupt mode > >>or bind eventfd to interrupt notifications (similarly to vfio ioctl > >>VFIO_DEVICE_SET_IRQS). > >> > >>Signed-off-by: Vlad Zolotarov > >>--- > >> drivers/uio/uio.c | 15 +++++++++++++++ > >> include/linux/uio_driver.h | 3 +++ > >> 2 files changed, 18 insertions(+) > >> > >>diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c > >>index 8196581..714b0e5 100644 > >>--- a/drivers/uio/uio.c > >>+++ b/drivers/uio/uio.c > >>@@ -704,6 +704,20 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) > >> } > >> } > >>+static long uio_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) > >>+{ > >>+ struct uio_listener *listener = filep->private_data; > >>+ struct uio_device *idev = listener->dev; > >>+ > >>+ if (!idev->info) > >>+ return -EIO; > >>+ > >>+ if (!idev->info->ioctl) > >>+ return -ENOTTY; > >>+ > >>+ return idev->info->ioctl(idev->info, cmd, arg); > >>+} > >As Stephen said, I will not take this, sorry. It opens up the ability > >to add "new system calls" to a huge range of crappy drivers, it's > >something that vendors have been trying to push for years and is > >something that I will not allow. > > Ok. Another alternative could be to add new sysfs attributes for the MSI-X > functionality similarly to what is done with "maps". > Would it be acceptable? If you get everyone else here to agree that this is the interface you all are going to be using, sure. All I care is that you not add ioctl to the UIO interface. greg k-h