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Commit e0466156 authored by Felipe F. Tonello's avatar Felipe F. Tonello Committed by Felipe Balbi
Browse files

usb: gadget: align buffer size when allocating for OUT endpoint 



Using usb_ep_align() makes sure that the buffer size for OUT endpoints is
always aligned with wMaxPacketSize (512 usually). This makes sure
that no buffer has the wrong size, which can cause nasty bugs.

Signed-off-by: default avatarFelipe F. Tonello <eu@felipetonello.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 69bb9973

drivers/usb/gadget/u_f.c

+3 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
 */



#include "u_f.h"

#include <linux/usb/ch9.h>



struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len)

{
@@ -20,6 +21,8 @@ struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len) 
	req = usb_ep_alloc_request(ep, GFP_ATOMIC);

	if (req) {

		req->length = len ?: default_len;

		if (usb_endpoint_dir_out(ep->desc))

			req->length = usb_ep_align(ep, req->length);

		req->buf = kmalloc(req->length, GFP_ATOMIC);

		if (!req->buf) {

			usb_ep_free_request(ep, req);

drivers/usb/gadget/u_f.h

+15 −1
Original line number Diff line number Diff line
@@ -47,8 +47,22 @@ 
struct usb_ep;

struct usb_request;



/* Requests allocated via alloc_ep_req() must be freed by free_ep_req(). */

/**

 * alloc_ep_req - returns a usb_request allocated by the gadget driver and

 * allocates the request's buffer.

 *

 * @ep: the endpoint to allocate a usb_request

 * @len: usb_requests's buffer suggested size

 * @default_len: used if @len is not provided, ie, is 0

 *

 * In case @ep direction is OUT, the @len will be aligned to ep's

 * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use

 * usb_requests's length (req->length) to refer to the allocated buffer size.

 * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().

 */

struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len);



/* Frees a usb_request previously allocated by alloc_ep_req() */

static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)

{

	kfree(req->buf);