Thread (9 messages) 9 messages, 2 authors, 2021-10-04
STALE1718d
Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH v2 7/7] usb: gadget: udc: ensure the gadget is still available

From: Michael Grzeschik <hidden>
Date: 2021-10-03 20:29:48
Subsystem: the rest, usb subsystem · Maintainers: Linus Torvalds, Greg Kroah-Hartman

It is possible that the configfs gadget layer will be calling the unbind
functions of all gadget functions on gadget_dev_desc_UDC_store and
cleaned up the cdev structures pointer to the gadget. This will not
prevent the usage of the usb_function_de/activate functions.

f_obex and f_uvc are the candidates to still call the functions with no
valid gadget set. This patch prevents the usage of the gadget if it was
already unset.

Signed-off-by: Michael Grzeschik <redacted>
---
v2: - no changes

 drivers/usb/gadget/composite.c | 4 ++--
 drivers/usb/gadget/udc/core.c  | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 504c1cbc255d1..1b4cd01e2ae13 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -393,7 +393,7 @@ int usb_function_deactivate(struct usb_function *function)
 
 	spin_lock_irqsave(&cdev->lock, flags);
 
-	if (cdev->deactivations == 0) {
+	if (cdev->deactivations == 0 && cdev->gadget) {
 		spin_unlock_irqrestore(&cdev->lock, flags);
 		status = usb_gadget_deactivate(cdev->gadget);
 		spin_lock_irqsave(&cdev->lock, flags);
@@ -428,7 +428,7 @@ int usb_function_activate(struct usb_function *function)
 		status = -EINVAL;
 	else {
 		cdev->deactivations--;
-		if (cdev->deactivations == 0) {
+		if (cdev->deactivations == 0 && cdev->gadget) {
 			spin_unlock_irqrestore(&cdev->lock, flags);
 			status = usb_gadget_activate(cdev->gadget);
 			spin_lock_irqsave(&cdev->lock, flags);
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 14fdf918ecfeb..52964d0e26fa6 100644
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -756,6 +756,9 @@ int usb_gadget_deactivate(struct usb_gadget *gadget)
 {
 	int ret = 0;
 
+	if (!gadget)
+		return ret;
+
 	if (gadget->deactivated)
 		goto out;
 
-- 
2.30.2
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