From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from lb2-smtp-cloud2.xs4all.net ([194.109.24.25]:46799 "EHLO lb2-smtp-cloud2.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755045AbcHVMxu (ORCPT ); Mon, 22 Aug 2016 08:53:50 -0400 Subject: Re: [PATCH v4 1/5] media: Determine early whether an IOCTL is supported To: Sakari Ailus , linux-media@vger.kernel.org References: <1470947358-31168-1-git-send-email-sakari.ailus@linux.intel.com> <1470947358-31168-2-git-send-email-sakari.ailus@linux.intel.com> Cc: laurent.pinchart@ideasonboard.com, mchehab@osg.samsung.com From: Hans Verkuil Message-ID: <9e27cb51-c37e-3751-a849-36299c8a334d@xs4all.nl> Date: Mon, 22 Aug 2016 14:53:45 +0200 MIME-Version: 1.0 In-Reply-To: <1470947358-31168-2-git-send-email-sakari.ailus@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 08/11/2016 10:29 PM, Sakari Ailus wrote: > Preparation for refactoring media IOCTL handling to unify common parts. > > Reviewed-by: Laurent Pinchart > Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil > --- > drivers/media/media-device.c | 54 ++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 52 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c > index 1795abe..aedd64e 100644 > --- a/drivers/media/media-device.c > +++ b/drivers/media/media-device.c > @@ -419,13 +419,41 @@ static long media_device_get_topology(struct media_device *mdev, > return 0; > } > > -static long media_device_ioctl(struct file *filp, unsigned int cmd, > - unsigned long arg) > +#define MEDIA_IOC(__cmd) \ > + [_IOC_NR(MEDIA_IOC_##__cmd)] = { .cmd = MEDIA_IOC_##__cmd } > + > +/* the table is indexed by _IOC_NR(cmd) */ > +struct media_ioctl_info { > + unsigned int cmd; > +}; > + > +static const struct media_ioctl_info ioctl_info[] = { > + MEDIA_IOC(DEVICE_INFO), > + MEDIA_IOC(ENUM_ENTITIES), > + MEDIA_IOC(ENUM_LINKS), > + MEDIA_IOC(SETUP_LINK), > + MEDIA_IOC(G_TOPOLOGY), > +}; > + > +static inline long is_valid_ioctl(const struct media_ioctl_info *info, > + unsigned int cmd) > +{ > + return (_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_info) > + || info[_IOC_NR(cmd)].cmd != cmd) ? -ENOIOCTLCMD : 0; > +} > + > +static long __media_device_ioctl( > + struct file *filp, unsigned int cmd, void __user *arg, > + const struct media_ioctl_info *info_array) > { > struct media_devnode *devnode = media_devnode_data(filp); > struct media_device *dev = devnode->media_dev; > long ret; > > + ret = is_valid_ioctl(info_array, cmd); > + if (ret) > + return ret; > + > mutex_lock(&dev->graph_mutex); > switch (cmd) { > case MEDIA_IOC_DEVICE_INFO: > @@ -461,6 +489,13 @@ static long media_device_ioctl(struct file *filp, unsigned int cmd, > return ret; > } > > +static long media_device_ioctl(struct file *filp, unsigned int cmd, > + unsigned long arg) > +{ > + return __media_device_ioctl( > + filp, cmd, (void __user *)arg, ioctl_info); > +} > + > #ifdef CONFIG_COMPAT > > struct media_links_enum32 { > @@ -491,6 +526,14 @@ static long media_device_enum_links32(struct media_device *mdev, > > #define MEDIA_IOC_ENUM_LINKS32 _IOWR('|', 0x02, struct media_links_enum32) > > +static const struct media_ioctl_info compat_ioctl_info[] = { > + MEDIA_IOC(DEVICE_INFO), > + MEDIA_IOC(ENUM_ENTITIES), > + MEDIA_IOC(ENUM_LINKS32), > + MEDIA_IOC(SETUP_LINK), > + MEDIA_IOC(G_TOPOLOGY), > +}; > + > static long media_device_compat_ioctl(struct file *filp, unsigned int cmd, > unsigned long arg) > { > @@ -498,6 +541,13 @@ static long media_device_compat_ioctl(struct file *filp, unsigned int cmd, > struct media_device *dev = devnode->media_dev; > long ret; > > + /* > + * The number of supported IOCTLs is the same for both regular and > + * compat cases. Instead of passing the sizes around, ensure that > + * they match. > + */ > + BUILD_BUG_ON(ARRAY_SIZE(ioctl_info) != ARRAY_SIZE(compat_ioctl_info)); > + > switch (cmd) { > case MEDIA_IOC_ENUM_LINKS32: > mutex_lock(&dev->graph_mutex); >