{"id":3313,"url":"https://patchwork.libcamera.org/api/patches/3313/?format=json","web_url":"https://patchwork.libcamera.org/patch/3313/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20200324202844.1518292-3-jacopo@jmondi.org>","date":"2020-03-24T20:28:42","name":"[libcamera-devel,2/4] media: v4l2-dev: Add v4l2_device_register_ro_subdev_node()","commit_ref":null,"pull_url":null,"state":"superseded","archived":false,"hash":"7d52c349b27a9b8aad67aefab95add3acd6d3495","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/?format=json","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/3313/mbox/","series":[{"id":772,"url":"https://patchwork.libcamera.org/api/series/772/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=772","date":"2020-03-24T20:28:40","name":"media: Register read-only sub-dev devnode","version":1,"mbox":"https://patchwork.libcamera.org/series/772/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/3313/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/3313/checks/","tags":{},"headers":{"Return-Path":"","Received":["from relay11.mail.gandi.net (relay11.mail.gandi.net\n\t[217.70.178.231])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 8CF5660411\n\tfor ;\n\tTue, 24 Mar 2020 21:25:56 +0100 (CET)","from localhost.localdomain (2-224-242-101.ip172.fastwebnet.it\n\t[2.224.242.101]) (Authenticated sender: jacopo@jmondi.org)\n\tby relay11.mail.gandi.net (Postfix) with ESMTPSA id 60155100010;\n\tTue, 24 Mar 2020 20:25:55 +0000 (UTC)"],"From":"Jacopo Mondi ","To":"linux-media@vger.kernel.org,\n\tlibcamera-devel@lists.libcamera.org","Cc":"Jacopo Mondi , mchehab@kernel.org,\n\thverkuil-cisco@xs4all.nl, sakari.ailus@linux.intel.com","Date":"Tue, 24 Mar 2020 21:28:42 +0100","Message-Id":"<20200324202844.1518292-3-jacopo@jmondi.org>","X-Mailer":"git-send-email 2.25.1","In-Reply-To":"<20200324202844.1518292-1-jacopo@jmondi.org>","References":"<20200324202844.1518292-1-jacopo@jmondi.org>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Subject":"[libcamera-devel] [PATCH 2/4] media: v4l2-dev: Add\n\tv4l2_device_register_ro_subdev_node()","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","X-List-Received-Date":"Tue, 24 Mar 2020 20:25:56 -0000"},"content":"Add to the V4L2 code a function to register device nodes for video\nsubdevices in read-only mode.\n\nRegistering a device node in read-only mode is useful to expose to\nuserspace the current sub-device configuration, without allowing\napplication to change it by using the V4L2 subdevice ioctls.\n\nSigned-off-by: Jacopo Mondi \n---\n drivers/media/v4l2-core/v4l2-device.c | 16 +++++++++++++++-\n drivers/media/v4l2-core/v4l2-subdev.c | 19 +++++++++++++++++++\n include/media/v4l2-dev.h | 7 +++++++\n include/media/v4l2-device.h | 10 ++++++++++\n 4 files changed, 51 insertions(+), 1 deletion(-)","diff":"diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c\nindex 63d6b147b21e..6f9dba36eda1 100644\n--- a/drivers/media/v4l2-core/v4l2-device.c\n+++ b/drivers/media/v4l2-core/v4l2-device.c\n@@ -188,7 +188,8 @@ static void v4l2_device_release_subdev_node(struct video_device *vdev)\n \tkfree(vdev);\n }\n \n-int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)\n+int __v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev,\n+\t\t\t\t\tbool read_only)\n {\n \tstruct video_device *vdev;\n \tstruct v4l2_subdev *sd;\n@@ -217,6 +218,8 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)\n \t\tvdev->fops = &v4l2_subdev_fops;\n \t\tvdev->release = v4l2_device_release_subdev_node;\n \t\tvdev->ctrl_handler = sd->ctrl_handler;\n+\t\tif (read_only)\n+\t\t\tvdev->flags |= V4L2_FL_RO_DEVNODE;\n \t\terr = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,\n \t\t\t\t\t sd->owner);\n \t\tif (err < 0) {\n@@ -254,8 +257,19 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)\n \n \treturn err;\n }\n+\n+int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)\n+{\n+\treturn __v4l2_device_register_subdev_nodes(v4l2_dev, false);\n+}\n EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);\n \n+int v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev)\n+{\n+\treturn __v4l2_device_register_subdev_nodes(v4l2_dev, true);\n+}\n+EXPORT_SYMBOL_GPL(v4l2_device_register_ro_subdev_nodes);\n+\n void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)\n {\n \tstruct v4l2_device *v4l2_dev;\ndiff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c\nindex f725cd9b66b9..9247ee6c293f 100644\n--- a/drivers/media/v4l2-core/v4l2-subdev.c\n+++ b/drivers/media/v4l2-core/v4l2-subdev.c\n@@ -331,6 +331,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \tstruct v4l2_fh *vfh = file->private_data;\n #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)\n \tstruct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);\n+\tbool ro_devnode = !!(vdev->flags & V4L2_FL_RO_DEVNODE);\n \tint rval;\n #endif\n \n@@ -453,6 +454,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \tcase VIDIOC_SUBDEV_S_FMT: {\n \t\tstruct v4l2_subdev_format *format = arg;\n \n+\t\tif (format->which != V4L2_SUBDEV_FORMAT_TRY && ro_devnode)\n+\t\t\treturn -EPERM;\n+\n \t\tmemset(format->reserved, 0, sizeof(format->reserved));\n \t\tmemset(format->format.reserved, 0, sizeof(format->format.reserved));\n \t\treturn v4l2_subdev_call(sd, pad, set_fmt, subdev_fh->pad, format);\n@@ -480,6 +484,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \t\tstruct v4l2_subdev_crop *crop = arg;\n \t\tstruct v4l2_subdev_selection sel;\n \n+\t\tif (crop->which != V4L2_SUBDEV_FORMAT_TRY && ro_devnode)\n+\t\t\treturn -EPERM;\n+\n \t\tmemset(crop->reserved, 0, sizeof(crop->reserved));\n \t\tmemset(&sel, 0, sizeof(sel));\n \t\tsel.which = crop->which;\n@@ -521,6 +528,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \tcase VIDIOC_SUBDEV_S_FRAME_INTERVAL: {\n \t\tstruct v4l2_subdev_frame_interval *fi = arg;\n \n+\t\tif (ro_devnode)\n+\t\t\treturn -EPERM;\n+\n \t\tmemset(fi->reserved, 0, sizeof(fi->reserved));\n \t\treturn v4l2_subdev_call(sd, video, s_frame_interval, arg);\n \t}\n@@ -544,6 +554,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \tcase VIDIOC_SUBDEV_S_SELECTION: {\n \t\tstruct v4l2_subdev_selection *sel = arg;\n \n+\t\tif (sel->which != V4L2_SUBDEV_FORMAT_TRY && ro_devnode)\n+\t\t\treturn -EPERM;\n+\n \t\tmemset(sel->reserved, 0, sizeof(sel->reserved));\n \t\treturn v4l2_subdev_call(\n \t\t\tsd, pad, set_selection, subdev_fh->pad, sel);\n@@ -580,6 +593,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \t\treturn v4l2_subdev_call(sd, video, g_dv_timings, arg);\n \n \tcase VIDIOC_SUBDEV_S_DV_TIMINGS:\n+\t\tif (ro_devnode)\n+\t\t\treturn -EPERM;\n+\n \t\treturn v4l2_subdev_call(sd, video, s_dv_timings, arg);\n \n \tcase VIDIOC_SUBDEV_G_STD:\n@@ -588,6 +604,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)\n \tcase VIDIOC_SUBDEV_S_STD: {\n \t\tv4l2_std_id *std = arg;\n \n+\t\tif (ro_devnode)\n+\t\t\treturn -EPERM;\n+\n \t\treturn v4l2_subdev_call(sd, video, s_std, *std);\n \t}\n \ndiff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h\nindex 48531e57cc5a..029873a338f2 100644\n--- a/include/media/v4l2-dev.h\n+++ b/include/media/v4l2-dev.h\n@@ -82,11 +82,18 @@ struct v4l2_ctrl_handler;\n *\tbut the old crop API will still work as expected in order to preserve\n *\tbackwards compatibility.\n *\tNever set this flag for new drivers.\n+ * @V4L2_FL_RO_DEVNODE:\n+ *\tindicates that the video device node is registered in read-only mode.\n+ *\tThe flag only applies to device nodes registered for sub-devices, it is\n+ *\tset by the core when the sub-devices device nodes are registered with\n+ *\tv4l2_device_register_ro_subdev_nodes() and used by the sub-device ioctl\n+ *\thandler to restrict access to some ioctl calls.\n */\n enum v4l2_video_device_flags {\n \tV4L2_FL_REGISTERED\t\t= 0,\n \tV4L2_FL_USES_V4L2_FH\t\t= 1,\n \tV4L2_FL_QUIRK_INVERTED_CROP\t= 2,\n+\tV4L2_FL_RO_DEVNODE\t\t= 3,\n };\n \n /* Priority helper functions */\ndiff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h\nindex e0b8f2602670..0df667ba9938 100644\n--- a/include/media/v4l2-device.h\n+++ b/include/media/v4l2-device.h\n@@ -183,6 +183,16 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);\n int __must_check\n v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);\n \n+/**\n+ * v4l2_device_register_ro_subdev_nodes - Registers read-only device nodes for\n+ * all subdevs of the v4l2 device that are marked with the\n+ * %V4L2_SUBDEV_FL_HAS_DEVNODE flag.\n+ *\n+ * @v4l2_dev: pointer to struct v4l2_device\n+ */\n+int __must_check\n+v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev);\n+\n /**\n * v4l2_subdev_notify - Sends a notification to v4l2_device.\n *\n","prefixes":["libcamera-devel","2/4"]}