From 8fb91b33c6bfa3ac5e4ad76920b7bcd7bdbbb6d0 Mon Sep 17 00:00:00 2001 From: Martin Rubli Date: Wed, 8 Sep 2010 04:15:23 -0300 Subject: [PATCH] [media] uvcvideo: Remove sysadmin requirements for UVCIOC_CTRL_MAP This patch removes the sysadmin requirements for UVCIOC_CTRL_MAP (and the stub implementation of UVCIOC_CTRL_ADD). This requirement no longer makes sense with the new XU control access mechanisms since XU controls can be accessed without adding control mappings first. A maximum number (currently 1024) of control mappings per device is enforced to avoid excess memory consumption caused by careless user space applications. Signed-off-by: Martin Rubli Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_ctrl.c | 14 ++++++++++++++ drivers/media/video/uvc/uvc_driver.c | 1 + drivers/media/video/uvc/uvc_v4l2.c | 6 ------ drivers/media/video/uvc/uvcvideo.h | 4 ++++ 4 files changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c index 2c81b7f35551..531a3e1a6d17 100644 --- a/drivers/media/video/uvc/uvc_ctrl.c +++ b/drivers/media/video/uvc/uvc_ctrl.c @@ -1435,6 +1435,7 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain, struct uvc_entity *entity; struct uvc_control *ctrl; int found = 0; + int ret; if (mapping->id & ~V4L2_CTRL_ID_MASK) { uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', control " @@ -1478,7 +1479,20 @@ int uvc_ctrl_add_mapping(struct uvc_video_chain *chain, } } + /* Prevent excess memory consumption */ + if (atomic_inc_return(&dev->nmappings) > UVC_MAX_CONTROL_MAPPINGS) { + atomic_dec(&dev->nmappings); + uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', maximum " + "mappings count (%u) exceeded.\n", mapping->name, + UVC_MAX_CONTROL_MAPPINGS); + ret = -ENOMEM; + goto done; + } + ret = __uvc_ctrl_add_mapping(dev, ctrl, mapping); + if (ret < 0) + atomic_dec(&dev->nmappings); + done: mutex_unlock(&chain->ctrl_mutex); return ret; diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c index 71efda76cc73..a1e9dfb52f69 100644 --- a/drivers/media/video/uvc/uvc_driver.c +++ b/drivers/media/video/uvc/uvc_driver.c @@ -1760,6 +1760,7 @@ static int uvc_probe(struct usb_interface *intf, INIT_LIST_HEAD(&dev->streams); atomic_set(&dev->nstreams, 0); atomic_set(&dev->users, 0); + atomic_set(&dev->nmappings, 0); dev->udev = usb_get_dev(udev); dev->intf = usb_get_intf(intf); diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c index 4a510483f7c5..6d15de9b5204 100644 --- a/drivers/media/video/uvc/uvc_v4l2.c +++ b/drivers/media/video/uvc/uvc_v4l2.c @@ -1025,16 +1025,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg) /* Dynamic controls. */ case UVCIOC_CTRL_ADD: /* Legacy ioctl, kept for API compatibility reasons */ - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - return -EEXIST; case UVCIOC_CTRL_MAP_OLD: case UVCIOC_CTRL_MAP: - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - return uvc_ioctl_ctrl_map(chain, arg, cmd == UVCIOC_CTRL_MAP_OLD); diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h index 34637fbbbd61..39e9e36e8839 100644 --- a/drivers/media/video/uvc/uvcvideo.h +++ b/drivers/media/video/uvc/uvcvideo.h @@ -172,6 +172,9 @@ struct uvc_xu_control { #define UVC_CTRL_CONTROL_TIMEOUT 300 #define UVC_CTRL_STREAMING_TIMEOUT 5000 +/* Maximum allowed number of control mappings per device */ +#define UVC_MAX_CONTROL_MAPPINGS 1024 + /* Devices quirks */ #define UVC_QUIRK_STATUS_INTERVAL 0x00000001 #define UVC_QUIRK_PROBE_MINMAX 0x00000002 @@ -472,6 +475,7 @@ struct uvc_device { enum uvc_device_state state; atomic_t users; + atomic_t nmappings; /* Video control interface */ __u16 uvc_version;