Struct device holding cdev should not be freed unless cdev is not in use. It is possible that user space has opened char device while kernel has freed the associated struct device context. Mark dev kobj as parent of cdev, so that chardev_add gets an extra reference to dev. This ensures device context is not freed until cdev is is not in uses. --- drivers/rpmsg/rpmsg_char.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index c03a118..72ee101 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -417,6 +417,7 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, dev->id = ret; dev_set_name(dev, "rpmsg%d", ret); + cdev_set_parent(&eptdev->cdev, &dev->kobj); ret = cdev_add(&eptdev->cdev, dev->devt, 1); if (ret) goto free_ept_ida; @@ -533,6 +534,7 @@ static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) dev->id = ret; dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); + cdev_set_parent(&ctrldev->cdev, &dev->kobj); ret = cdev_add(&ctrldev->cdev, dev->devt, 1); if (ret) goto free_ctrl_ida; -- 2.7.4
