We always need to call put_device() if device_register() fails. All vfio drivers calling device_register() include a similar unwind stack via gotos, therefore split device_unregister() into its device_del() and put_device() components in the unwind path, and add a goto target to handle only the put_device() requirement. Reported-by: Ruan Jinjie <ruanjinjie@xxxxxxxxxx> Link: https://lore.kernel.org/all/20221118032827.3725190-1-ruanjinjie@xxxxxxxxxx Fixes: d61fc96f47fd ("sample: vfio mdev display - host device") Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.") Fixes: a5e6e6505f38 ("sample: vfio bochs vbe display (host device for bochs-drm)") Fixes: 9e6f07cd1eaa ("vfio/ccw: create a parent struct") Fixes: 36360658eb5a ("s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem") Cc: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> Cc: Halil Pasic <pasic@xxxxxxxxxxxxx> Cc: Jason Herne <jjherne@xxxxxxxxxxxxx> Cc: Kirti Wankhede <kwankhede@xxxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> Reviewed-by: Eric Farman <farman@xxxxxxxxxxxxx> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> --- I didn't intend to usurp Ruan's patch, but since the inline version is collecting reviews, formally post it and include additional fixes tags for vfio-ccw and vfio-ap. drivers/s390/cio/vfio_ccw_drv.c | 3 ++- drivers/s390/crypto/vfio_ap_drv.c | 2 +- samples/vfio-mdev/mbochs.c | 7 ++++--- samples/vfio-mdev/mdpy.c | 7 ++++--- samples/vfio-mdev/mtty.c | 7 ++++--- 5 files changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index c2a65808605a..54aba7cceb33 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -199,8 +199,9 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) return 0; out_unreg: - device_unregister(&parent->dev); + device_del(&parent->dev); out_free: + put_device(&parent->dev); dev_set_drvdata(&sch->dev, NULL); return ret; } diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c index f43cfeabd2cc..997b524bdd2b 100644 --- a/drivers/s390/crypto/vfio_ap_drv.c +++ b/drivers/s390/crypto/vfio_ap_drv.c @@ -122,7 +122,7 @@ static int vfio_ap_matrix_dev_create(void) return 0; matrix_drv_err: - device_unregister(&matrix_dev->device); + device_del(&matrix_dev->device); matrix_reg_err: put_device(&matrix_dev->device); matrix_alloc_err: diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c index 8b5a3a778a25..e54eb752e1ba 100644 --- a/samples/vfio-mdev/mbochs.c +++ b/samples/vfio-mdev/mbochs.c @@ -1430,7 +1430,7 @@ static int __init mbochs_dev_init(void) ret = device_register(&mbochs_dev); if (ret) - goto err_class; + goto err_put; ret = mdev_register_parent(&mbochs_parent, &mbochs_dev, &mbochs_driver, mbochs_mdev_types, @@ -1441,8 +1441,9 @@ static int __init mbochs_dev_init(void) return 0; err_device: - device_unregister(&mbochs_dev); -err_class: + device_del(&mbochs_dev); +err_put: + put_device(&mbochs_dev); class_destroy(mbochs_class); err_driver: mdev_unregister_driver(&mbochs_driver); diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index 721fb06c6413..e8400fdab71d 100644 --- a/samples/vfio-mdev/mdpy.c +++ b/samples/vfio-mdev/mdpy.c @@ -717,7 +717,7 @@ static int __init mdpy_dev_init(void) ret = device_register(&mdpy_dev); if (ret) - goto err_class; + goto err_put; ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver, mdpy_mdev_types, @@ -728,8 +728,9 @@ static int __init mdpy_dev_init(void) return 0; err_device: - device_unregister(&mdpy_dev); -err_class: + device_del(&mdpy_dev); +err_put: + put_device(&mdpy_dev); class_destroy(mdpy_class); err_driver: mdev_unregister_driver(&mdpy_driver); diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index 3c2a421b9b69..e887de672c52 100644 --- a/samples/vfio-mdev/mtty.c +++ b/samples/vfio-mdev/mtty.c @@ -1330,7 +1330,7 @@ static int __init mtty_dev_init(void) ret = device_register(&mtty_dev.dev); if (ret) - goto err_class; + goto err_put; ret = mdev_register_parent(&mtty_dev.parent, &mtty_dev.dev, &mtty_driver, mtty_mdev_types, @@ -1340,8 +1340,9 @@ static int __init mtty_dev_init(void) return 0; err_device: - device_unregister(&mtty_dev.dev); -err_class: + device_del(&mtty_dev.dev); +err_put: + put_device(&mtty_dev.dev); class_destroy(mtty_dev.vd_class); err_driver: mdev_unregister_driver(&mtty_driver);
