[PATCH 5.10 094/122] usb: roles: dont get/set_role() when usb_role_switch is unregistered
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2024-02-27 14:29:49
Also in:
linux-patches
5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xu Yang <xu.yang_2@nxp.com>
commit b787a3e781759026a6212736ef8e52cf83d1821a upstream.
There is a possibility that usb_role_switch device is unregistered before
the user put usb_role_switch. In this case, the user may still want to
get/set_role() since the user can't sense the changes of usb_role_switch.
This will add a flag to show if usb_role_switch is already registered and
avoid unwanted behaviors.
Fixes: fde0aa6c175a ("usb: common: Small class for USB role switches")
cc: stable@vger.kernel.org
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240129093739.2371530-2-xu.yang_2@nxp.com (local)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/roles/class.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c@@ -21,6 +21,7 @@ struct usb_role_switch { struct mutex lock; /* device lock*/ struct module *module; /* the module this device depends on */ enum usb_role role; + bool registered; /* From descriptor */ struct device *usb2_port;
@@ -47,6 +48,9 @@ int usb_role_switch_set_role(struct usb_ if (IS_ERR_OR_NULL(sw)) return 0; + if (!sw->registered) + return -EOPNOTSUPP; + mutex_lock(&sw->lock); ret = sw->set(sw, role);
@@ -72,7 +76,7 @@ enum usb_role usb_role_switch_get_role(s { enum usb_role role; - if (IS_ERR_OR_NULL(sw)) + if (IS_ERR_OR_NULL(sw) || !sw->registered) return USB_ROLE_NONE; mutex_lock(&sw->lock);
@@ -347,6 +351,8 @@ usb_role_switch_register(struct device * return ERR_PTR(ret); } + sw->registered = true; + /* TODO: Symlinks for the host port and the device controller. */ return sw;
@@ -361,8 +367,10 @@ EXPORT_SYMBOL_GPL(usb_role_switch_regist */ void usb_role_switch_unregister(struct usb_role_switch *sw) { - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { + sw->registered = false; device_unregister(&sw->dev); + } } EXPORT_SYMBOL_GPL(usb_role_switch_unregister);