usb: gadget: dummy_hcd: remove usage of list iterator past the loop body

[ Upstream commit 7975f080d3557725160a878b1a64339043ba3d91 ]

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable [1].

Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-26-jakobkoschel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 8d63c83d8eb9 ("USB: gadget: dummy-hcd: Fix locking bug in RT-enabled kernels")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index 92d01ddaee0d4a706d97445eaf371acf625968e2..7ed83241cf69d0f584e76eabf93a2d5ddab41ea7 100644 (file)
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -749,7 +749,7 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
        struct dummy            *dum;
        int                     retval = -EINVAL;
        unsigned long           flags;
-       struct dummy_request    *req = NULL;
+       struct dummy_request    *req = NULL, *iter;
 
        if (!_ep || !_req)
                return retval;
@@ -761,13 +761,14 @@ static int dummy_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 
        local_irq_save(flags);
        spin_lock(&dum->lock);
-       list_for_each_entry(req, &ep->queue, queue) {
-               if (&req->req == _req) {
-                       list_del_init(&req->queue);
-                       _req->status = -ECONNRESET;
-                       retval = 0;
-                       break;
-               }
+       list_for_each_entry(iter, &ep->queue, queue) {
+               if (&iter->req != _req)
+                       continue;
+               list_del_init(&iter->queue);
+               _req->status = -ECONNRESET;
+               req = iter;
+               retval = 0;
+               break;
        }
        spin_unlock(&dum->lock);