struct rpmsg_eptdev contains a struct cdev. The current code frees
the rpmsg_eptdev struct in rpmsg_eptdev_destroy(), but the cdev is
a managed object, therefore its release is not predictable and the
rpmsg_eptdev could be freed before the cdev is entirely released.
The cdev_device_add/del() API was created to address this issue
(see commit 233ed09d7fda), use it instead of cdev add/del().
Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface")
Suggested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
Changes in v6:
- remove cdev_del() from rpmsg_eptdev_release_device()
- added 'Reviewed-by' tag from Mathieu and 'Suggested-by' tag
Changes in v5:
- patch added to the series
drivers/rpmsg/rpmsg_char.c | 11 ++---------
1 file changed, 2 insertions(+), 9 deletions(-)
diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index ba85f5d11960..49dd5a200998 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -92,7 +92,7 @@ static int rpmsg_eptdev_destroy(struct device *dev, void *data)
/* wake up any blocked readers */
wake_up_interruptible(&eptdev->readq);
- device_del(&eptdev->dev);
+ cdev_device_del(&eptdev->cdev, &eptdev->dev);
put_device(&eptdev->dev);
return 0;
@@ -335,7 +335,6 @@ static void rpmsg_eptdev_release_device(struct device *dev)
ida_simple_remove(&rpmsg_ept_ida, dev->id);
ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt));
- cdev_del(&eptdev->cdev);
kfree(eptdev);
}
@@ -380,19 +379,13 @@ static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev,
dev->id = ret;
dev_set_name(dev, "rpmsg%d", ret);
- ret = cdev_add(&eptdev->cdev, dev->devt, 1);
+ ret = cdev_device_add(&eptdev->cdev, &eptdev->dev);
if (ret)
goto free_ept_ida;
/* We can now rely on the release function for cleanup */
dev->release = rpmsg_eptdev_release_device;
- ret = device_add(dev);
- if (ret) {
- dev_err(dev, "device_add failed: %d\n", ret);
- put_device(dev);
- }
-
return ret;
free_ept_ida:
--
2.34.1.575.g55b058a8bb-goog
