From patchwork Wed Apr 29 08:58:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 3609 X-Patchwork-Delegate: jacopo@jmondi.org Return-Path: Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id CE2E5601B8 for ; Wed, 29 Apr 2020 10:55:51 +0200 (CEST) X-Originating-IP: 2.224.242.101 Received: from uno.lan (2-224-242-101.ip172.fastwebnet.it [2.224.242.101]) (Authenticated sender: jacopo@jmondi.org) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 6E784C000E; Wed, 29 Apr 2020 08:55:49 +0000 (UTC) From: Jacopo Mondi To: linux-media@vger.kernel.org, libcamera-devel@lists.libcamera.org Cc: Jacopo Mondi , mchehab@kernel.org, hverkuil-cisco@xs4all.nl, sakari.ailus@linux.intel.com, andrey.konovalov@linaro.org, laurent.pinchart@ideasonboard.com Date: Wed, 29 Apr 2020 10:58:55 +0200 Message-Id: <20200429085855.186273-1-jacopo@jmondi.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200428210609.6793-5-jacopo@jmondi.org> References: <20200428210609.6793-5-jacopo@jmondi.org> MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH v5.1] media: v4l2-subdev: Guard whole fops and ioctl hdlr X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Apr 2020 08:55:52 -0000 A sub-device device node can be registered in user space only if the CONFIG_V4L2_SUBDEV_API Kconfig option is selected. Currently the open/close file operations and the ioctl handler have some parts of their implementations guarded by #if defined(CONFIG_V4L2_SUBDEV_API), while they are actually not accessible without a video device node registered to user space. Guard the whole open, close and ioctl handler and provide stubs if the V4L2_SUBDEV_API Kconfig option is not selected. This slightly reduces the kernel size when the option is not selected and simplifies the file ops and ioctl implementations. Signed-off-by: Jacopo Mondi --- A different approach compared to v5, which was anyway buggy and not a proper solution. Sending out for comments, while waiting for consensus on v5 [5/6] (reserved space in the ioctl argument vs versioning based on structure size) Compile tested with and without V4L2_SUBDEV_API Kconfig option enabled and with drivers that depends on it built-in or as modules. --- drivers/media/v4l2-core/v4l2-subdev.c | 39 +++++++++++++++++++++------ 1 file changed, 31 insertions(+), 8 deletions(-) -- 2.26.1 diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index 1dc263c2ca0a..6fef52880c99 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -22,24 +22,22 @@ #include #include +#if defined(CONFIG_V4L2_SUBDEV_API) static int subdev_fh_init(struct v4l2_subdev_fh *fh, struct v4l2_subdev *sd) { -#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) if (sd->entity.num_pads) { fh->pad = v4l2_subdev_alloc_pad_config(sd); if (fh->pad == NULL) return -ENOMEM; } -#endif + return 0; } static void subdev_fh_free(struct v4l2_subdev_fh *fh) { -#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) v4l2_subdev_free_pad_config(fh->pad); fh->pad = NULL; -#endif } static int subdev_open(struct file *file) @@ -111,6 +109,17 @@ static int subdev_close(struct file *file) return 0; } +#else /* CONFIG_V4L2_SUBDEV_API */ +static int subdev_open(struct file *file) +{ + return 0; +} + +static int subdev_close(struct file *file) +{ + return 0; +} +#endif /* CONFIG_V4L2_SUBDEV_API */ static inline int check_which(u32 which) { @@ -324,15 +333,14 @@ const struct v4l2_subdev_ops v4l2_subdev_call_wrappers = { }; EXPORT_SYMBOL(v4l2_subdev_call_wrappers); +#if defined(CONFIG_V4L2_SUBDEV_API) static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) { struct video_device *vdev = video_devdata(file); struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev); struct v4l2_fh *vfh = file->private_data; -#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh); bool ro_subdev = test_bit(V4L2_FL_SUBDEV_RO_DEVNODE, &vdev->flags); -#endif int rval; switch (cmd) { @@ -466,7 +474,6 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) return ret; } -#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API) case VIDIOC_SUBDEV_G_FMT: { struct v4l2_subdev_format *format = arg; @@ -646,7 +653,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) case VIDIOC_SUBDEV_QUERYSTD: return v4l2_subdev_call(sd, video, querystd, arg); -#endif + default: return v4l2_subdev_call(sd, core, ioctl, cmd, arg); } @@ -686,6 +693,22 @@ static long subdev_compat_ioctl32(struct file *file, unsigned int cmd, } #endif +#else /* CONFIG_V4L2_SUBDEV_API */ +static long subdev_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return 0; +} + +#ifdef CONFIG_COMPAT +static long subdev_compat_ioctl32(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return 0; +} +#endif +#endif /* CONFIG_V4L2_SUBDEV_API */ + static __poll_t subdev_poll(struct file *file, poll_table *wait) { struct video_device *vdev = video_devdata(file);