Re: [PATCH 4/5] media: uvcvideo: Protect uvc queue file operations against disconnect

kernel test robot
2020-09-01T17:07:12Z

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Hi Guenter,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.9-rc3 next-20200828]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Guenter-Roeck/media-uvcvideo-Fix-race-conditions/20200830-230715
base: git://linuxtv.org/media_tree.git master
config: x86_64-randconfig-s031-20200901 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce:
# apt-get install sparse
# sparse version: v0.6.2-191-g10164920-dirty
# save the attached .config to linux build tree
make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

sparse warnings: (new ones prefixed by >>)

>> drivers/media/usb/uvc/uvc_queue.c:402:21: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __poll_t [usertype] ret @@ got int @@
>> drivers/media/usb/uvc/uvc_queue.c:402:21: sparse: expected restricted __poll_t [usertype] ret
>> drivers/media/usb/uvc/uvc_queue.c:402:21: sparse: got int

# https://github.com/0day-ci/linux/commit/9128827e77bc077a6fefd3ca886a8466e84f7154
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Guenter-Roeck/media-uvcvideo-Fix-race-conditions/20200830-230715
git checkout 9128827e77bc077a6fefd3ca886a8466e84f7154
vim +402 drivers/media/usb/uvc/uvc_queue.c

393
394 __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
395 poll_table *wait)
396 {
397 struct uvc_streaming *stream = uvc_queue_to_stream(queue);
398 __poll_t ret;
399
400 mutex_lock(&queue->mutex);
401 if (!video_is_registered(&stream->vdev)) {
> 402 ret = -ENODEV;
403 goto unlock;
404 }
405 ret = vb2_poll(&queue->queue, file, wait);
406 unlock:
407 mutex_unlock(&queue->mutex);
408
409 return ret;
410 }
411

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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