[PATCH 4/4] rpmsg: char: Return error if user tries to destroy a default endpoint.

[Arnaud Pouliquen]

Using the RPMSG_DESTROY_EPT_IOCTL control, user application can
destroy an endpoint. This patch prevents to destroy a default endpoint
associated to a channel.

This update is needed to manage the "rpmsg-raw" channel. In this
case a default endpoint is used, destroying it without the
channel does not make sense.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
---
 drivers/rpmsg/rpmsg_char.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 3b850b218eb0..8c78a5a192c1 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -285,6 +285,10 @@ static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd,
 	if (cmd != RPMSG_DESTROY_EPT_IOCTL)
 		return -EINVAL;
 
+	/* Don't allow to destroy a default endpoint. */
+	if (!eptdev->rpdev || eptdev->ept == eptdev->rpdev->ept)
+		return -EPERM;
+
 	return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL);
 }
 
-- 
2.17.1