From: Kuen-Han Tsai khtsai@google.com
[ Upstream commit bfb1d99d969fe3b892db30848aeebfa19d21f57f ]
Gadget function drivers often have goto-based error handling in their bind paths, which can be bug-prone. Refactoring these paths to use __free() scope-based cleanup is desirable, but currently blocked.
The blocker is that usb_ep_free_request(ep, req) requires two parameters, while the __free() mechanism can only pass a pointer to the request itself.
Store an endpoint pointer in the struct usb_request. The pointer is populated centrally in usb_ep_alloc_request() on every successful allocation, making the request object self-contained.
Signed-off-by: Kuen-Han Tsai khtsai@google.com Link: https://lore.kernel.org/r/20250916-ready-v1-1-4997bf277548@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Link: https://lore.kernel.org/r/20250916-ready-v1-1-4997bf277548@google.com Stable-dep-of: 75a5b8d4ddd4 ("usb: gadget: f_ncm: Refactor bind path to use __free()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/gadget/udc/core.c | 3 +++ include/linux/usb/gadget.h | 2 ++ 2 files changed, 5 insertions(+)
diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index d709e24c1fd42..e3d63b8fa0f4c 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -194,6 +194,9 @@ struct usb_request *usb_ep_alloc_request(struct usb_ep *ep,
req = ep->ops->alloc_request(ep, gfp_flags);
+ if (req) + req->ep = ep; + trace_usb_ep_alloc_request(ep, req, req ? 0 : -ENOMEM);
return req; diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h index 0f28c5512fcb6..0f20794760887 100644 --- a/include/linux/usb/gadget.h +++ b/include/linux/usb/gadget.h @@ -32,6 +32,7 @@ struct usb_ep;
/** * struct usb_request - describes one i/o request + * @ep: The associated endpoint set by usb_ep_alloc_request(). * @buf: Buffer used for data. Always provide this; some controllers * only use PIO, or don't use DMA for some endpoints. * @dma: DMA address corresponding to 'buf'. If you don't set this @@ -98,6 +99,7 @@ struct usb_ep; */
struct usb_request { + struct usb_ep *ep; void *buf; unsigned length; dma_addr_t dma;