On 03/16/2016 06:04 AM, Mauro Carvalho Chehab wrote:
> When multiple drivers are sharing the media_device struct,
> one driver cannot know the right moment to cleanup the
> media_device struct, because it can happen only when the
> struct is not used by the other drivers.
>
> So, let's call media_device_cleanup() internally, and
> ensure that media_device_unregister() will do the right thing,
> if the media device is not fully initialized.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Tested bind_unbind au0828 loop 1000 times, followed by bind_unbind
snd_usb_audio loop 1000 times. Didn't see any lock warnings on a
KASAN enabled kernel (lock testing enabled). No use-after-free errors
during these runs.
Ran device removal test and rmmod and modprobe tests on both drivers.
Generated graph after the runs and the graph looks good.
For the au0828 and snd_usb_audio change:
Reviewed-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Tested-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
thanks,
-- Shuah
> ---
> drivers/media/common/siano/smsdvb-main.c | 1 -
> drivers/media/media-device.c | 13 ++++++-------
> drivers/media/pci/saa7134/saa7134-core.c | 1 -
> drivers/media/platform/exynos4-is/media-dev.c | 3 +--
> drivers/media/platform/omap3isp/isp.c | 1 -
> drivers/media/platform/s3c-camif/camif-core.c | 2 --
> drivers/media/platform/vsp1/vsp1_drv.c | 1 -
> drivers/media/platform/xilinx/xilinx-vipp.c | 3 +--
> drivers/media/usb/au0828/au0828-core.c | 1 -
> drivers/media/usb/cx231xx/cx231xx-cards.c | 1 -
> drivers/media/usb/dvb-usb-v2/dvb_usb_core.c | 1 -
> drivers/media/usb/dvb-usb/dvb-usb-dvb.c | 1 -
> drivers/media/usb/em28xx/em28xx-cards.c | 1 -
> drivers/media/usb/siano/smsusb.c | 2 +-
> drivers/media/usb/uvc/uvc_driver.c | 4 +---
> include/media/media-device.h | 10 ----------
> 16 files changed, 10 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/media/common/siano/smsdvb-main.c b/drivers/media/common/siano/smsdvb-main.c
> index 9148e14c9d07..711c389c05e3 100644
> --- a/drivers/media/common/siano/smsdvb-main.c
> +++ b/drivers/media/common/siano/smsdvb-main.c
> @@ -617,7 +617,6 @@ static void smsdvb_media_device_unregister(struct smsdvb_client_t *client)
> if (!coredev->media_dev)
> return;
> media_device_unregister(coredev->media_dev);
> - media_device_cleanup(coredev->media_dev);
> kfree(coredev->media_dev);
> coredev->media_dev = NULL;
> #endif
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 38e6c319fe6e..0c7371eeda84 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -707,14 +707,12 @@ void media_device_init(struct media_device *mdev)
> }
> EXPORT_SYMBOL_GPL(media_device_init);
>
> -void media_device_cleanup(struct media_device *mdev)
> +static void media_device_cleanup(struct media_device *mdev)
> {
> ida_destroy(&mdev->entity_internal_idx);
> mdev->entity_internal_idx_max = 0;
> media_entity_graph_walk_cleanup(&mdev->pm_count_walk);
> - mutex_destroy(&mdev->graph_mutex);
> }
> -EXPORT_SYMBOL_GPL(media_device_cleanup);
>
> int __must_check __media_device_register(struct media_device *mdev,
> struct module *owner)
> @@ -812,11 +810,12 @@ static void do_media_device_unregister(struct kref *kref)
> }
>
> /* Check if mdev devnode was registered */
> - if (!media_devnode_is_registered(&mdev->devnode))
> - return;
> + if (media_devnode_is_registered(&mdev->devnode)) {
> + device_remove_file(&mdev->devnode.dev, &dev_attr_model);
> + media_devnode_unregister(&mdev->devnode);
> + }
>
> - device_remove_file(&mdev->devnode.dev, &dev_attr_model);
> - media_devnode_unregister(&mdev->devnode);
> + media_device_cleanup(mdev);
>
> dev_dbg(mdev->dev, "Media device unregistered\n");
> }
> diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
> index c0e1780ec831..213dc71f09eb 100644
> --- a/drivers/media/pci/saa7134/saa7134-core.c
> +++ b/drivers/media/pci/saa7134/saa7134-core.c
> @@ -813,7 +813,6 @@ static void saa7134_unregister_media_device(struct saa7134_dev *dev)
> if (!dev->media_dev)
> return;
> media_device_unregister(dev->media_dev);
> - media_device_cleanup(dev->media_dev);
> kfree(dev->media_dev);
> dev->media_dev = NULL;
> #endif
> diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c
> index feb521f28e14..8c106fda7b84 100644
> --- a/drivers/media/platform/exynos4-is/media-dev.c
> +++ b/drivers/media/platform/exynos4-is/media-dev.c
> @@ -1501,7 +1501,7 @@ err_clk:
> err_m_ent:
> fimc_md_unregister_entities(fmd);
> err_md:
> - media_device_cleanup(&fmd->media_dev);
> + media_device_unregister(&fmd->media_dev);
> v4l2_device_unregister(&fmd->v4l2_dev);
> return ret;
> }
> @@ -1521,7 +1521,6 @@ static int fimc_md_remove(struct platform_device *pdev)
> fimc_md_unregister_entities(fmd);
> fimc_md_pipelines_free(fmd);
> media_device_unregister(&fmd->media_dev);
> - media_device_cleanup(&fmd->media_dev);
> fimc_md_put_clocks(fmd);
>
> return 0;
> diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
> index 5d54e2c6c16b..cd67edcad8d3 100644
> --- a/drivers/media/platform/omap3isp/isp.c
> +++ b/drivers/media/platform/omap3isp/isp.c
> @@ -1598,7 +1598,6 @@ static void isp_unregister_entities(struct isp_device *isp)
>
> v4l2_device_unregister(&isp->v4l2_dev);
> media_device_unregister(&isp->media_dev);
> - media_device_cleanup(&isp->media_dev);
> }
>
> static int isp_link_entity(
> diff --git a/drivers/media/platform/s3c-camif/camif-core.c b/drivers/media/platform/s3c-camif/camif-core.c
> index 0b44b9accf50..0159f98da435 100644
> --- a/drivers/media/platform/s3c-camif/camif-core.c
> +++ b/drivers/media/platform/s3c-camif/camif-core.c
> @@ -521,7 +521,6 @@ err_unlock:
> err_sens:
> v4l2_device_unregister(&camif->v4l2_dev);
> media_device_unregister(&camif->media_dev);
> - media_device_cleanup(&camif->media_dev);
> camif_unregister_media_entities(camif);
> err_mdev:
> vb2_dma_contig_cleanup_ctx(camif->alloc_ctx);
> @@ -543,7 +542,6 @@ static int s3c_camif_remove(struct platform_device *pdev)
> struct s3c_camif_plat_data *pdata = &camif->pdata;
>
> media_device_unregister(&camif->media_dev);
> - media_device_cleanup(&camif->media_dev);
> camif_unregister_media_entities(camif);
> v4l2_device_unregister(&camif->v4l2_dev);
>
> diff --git a/drivers/media/platform/vsp1/vsp1_drv.c b/drivers/media/platform/vsp1/vsp1_drv.c
> index 25750a0e4631..2faefec89b62 100644
> --- a/drivers/media/platform/vsp1/vsp1_drv.c
> +++ b/drivers/media/platform/vsp1/vsp1_drv.c
> @@ -213,7 +213,6 @@ static void vsp1_destroy_entities(struct vsp1_device *vsp1)
>
> v4l2_device_unregister(&vsp1->v4l2_dev);
> media_device_unregister(&vsp1->media_dev);
> - media_device_cleanup(&vsp1->media_dev);
>
> if (!vsp1->info->uapi)
> vsp1_drm_cleanup(vsp1);
> diff --git a/drivers/media/platform/xilinx/xilinx-vipp.c b/drivers/media/platform/xilinx/xilinx-vipp.c
> index e795a4501e8b..ec4b21c64ef6 100644
> --- a/drivers/media/platform/xilinx/xilinx-vipp.c
> +++ b/drivers/media/platform/xilinx/xilinx-vipp.c
> @@ -573,7 +573,6 @@ static void xvip_composite_v4l2_cleanup(struct xvip_composite_device *xdev)
> {
> v4l2_device_unregister(&xdev->v4l2_dev);
> media_device_unregister(&xdev->media_dev);
> - media_device_cleanup(&xdev->media_dev);
> }
>
> static int xvip_composite_v4l2_init(struct xvip_composite_device *xdev)
> @@ -592,7 +591,7 @@ static int xvip_composite_v4l2_init(struct xvip_composite_device *xdev)
> if (ret < 0) {
> dev_err(xdev->dev, "V4L2 device registration failed (%d)\n",
> ret);
> - media_device_cleanup(&xdev->media_dev);
> + media_device_unregister(&xdev->media_dev);
> return ret;
> }
>
> diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
> index 06da73f1ff22..0a26ffff6f18 100644
> --- a/drivers/media/usb/au0828/au0828-core.c
> +++ b/drivers/media/usb/au0828/au0828-core.c
> @@ -158,7 +158,6 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
> dev->media_dev->disable_source = NULL;
>
> media_device_unregister(dev->media_dev);
> - media_device_cleanup(dev->media_dev);
> dev->media_dev = NULL;
> #endif
> }
> diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c
> index c63248a18823..438fe0761bda 100644
> --- a/drivers/media/usb/cx231xx/cx231xx-cards.c
> +++ b/drivers/media/usb/cx231xx/cx231xx-cards.c
> @@ -1172,7 +1172,6 @@ static void cx231xx_unregister_media_device(struct cx231xx *dev)
> #ifdef CONFIG_MEDIA_CONTROLLER
> if (dev->media_dev) {
> media_device_unregister(dev->media_dev);
> - media_device_cleanup(dev->media_dev);
> kfree(dev->media_dev);
> dev->media_dev = NULL;
> }
> diff --git a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
> index 3fbb2cd19f5e..238ecb3a510b 100644
> --- a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
> +++ b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
> @@ -438,7 +438,6 @@ static void dvb_usbv2_media_device_unregister(struct dvb_usb_adapter *adap)
> return;
>
> media_device_unregister(adap->dvb_adap.mdev);
> - media_device_cleanup(adap->dvb_adap.mdev);
> kfree(adap->dvb_adap.mdev);
> adap->dvb_adap.mdev = NULL;
>
> diff --git a/drivers/media/usb/dvb-usb/dvb-usb-dvb.c b/drivers/media/usb/dvb-usb/dvb-usb-dvb.c
> index 6477b04e95c7..093ca809b5f8 100644
> --- a/drivers/media/usb/dvb-usb/dvb-usb-dvb.c
> +++ b/drivers/media/usb/dvb-usb/dvb-usb-dvb.c
> @@ -132,7 +132,6 @@ static void dvb_usb_media_device_unregister(struct dvb_usb_adapter *adap)
> return;
>
> media_device_unregister(adap->dvb_adap.mdev);
> - media_device_cleanup(adap->dvb_adap.mdev);
> kfree(adap->dvb_adap.mdev);
> adap->dvb_adap.mdev = NULL;
> #endif
> diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
> index 930e3e3fc948..734ecfb890ff 100644
> --- a/drivers/media/usb/em28xx/em28xx-cards.c
> +++ b/drivers/media/usb/em28xx/em28xx-cards.c
> @@ -3091,7 +3091,6 @@ static void em28xx_unregister_media_device(struct em28xx *dev)
> #ifdef CONFIG_MEDIA_CONTROLLER
> if (dev->media_dev) {
> media_device_unregister(dev->media_dev);
> - media_device_cleanup(dev->media_dev);
> kfree(dev->media_dev);
> dev->media_dev = NULL;
> }
> diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c
> index c2e25876e93b..cbf9a34f2074 100644
> --- a/drivers/media/usb/siano/smsusb.c
> +++ b/drivers/media/usb/siano/smsusb.c
> @@ -375,7 +375,7 @@ static void *siano_media_device_register(struct smsusb_device_t *dev,
>
> ret = media_device_register(mdev);
> if (ret) {
> - media_device_cleanup(mdev);
> + media_device_unregister(mdev);
> kfree(mdev);
> return NULL;
> }
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index 451e84e962e2..dcce75e1aff2 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1674,9 +1674,7 @@ static void uvc_delete(struct uvc_device *dev)
> if (dev->vdev.dev)
> v4l2_device_unregister(&dev->vdev);
> #ifdef CONFIG_MEDIA_CONTROLLER
> - if (media_devnode_is_registered(&dev->mdev.devnode))
> - media_device_unregister(&dev->mdev);
> - media_device_cleanup(&dev->mdev);
> + media_device_unregister(&dev->mdev);
> #endif
>
> list_for_each_safe(p, n, &dev->chains) {
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index 73c16e6e6b6b..9166bff8068e 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -430,16 +430,6 @@ static inline __must_check int media_entity_enum_init(
> void media_device_init(struct media_device *mdev);
>
> /**
> - * media_device_cleanup() - Cleanups a media device element
> - *
> - * @mdev: pointer to struct &media_device
> - *
> - * This function that will destroy the graph_mutex that is
> - * initialized in media_device_init().
> - */
> -void media_device_cleanup(struct media_device *mdev);
> -
> -/**
> * __media_device_register() - Registers a media device element
> *
> * @mdev: pointer to struct &media_device
>
--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh@xxxxxxxxxxxxxxx | (970) 217-8978
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