From 8815bb09af21316aeb5f8948b24ac62181670db2 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Mon, 30 Apr 2012 09:13:46 +0200 Subject: usbhid: prevent deadlock during timeout On some HCDs usb_unlink_urb() can directly call the completion handler. That limits the spinlocks that can be taken in the handler to locks not held while calling usb_unlink_urb() To prevent a race with resubmission, this patch exposes usbcore's infrastructure for blocking submission, uses it and so drops the lock without causing a race in usbhid. Signed-off-by: Oliver Neukum Acked-by: Jiri Kosina Cc: stable Signed-off-by: Greg Kroah-Hartman --- include/linux/usb.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/usb.h') diff --git a/include/linux/usb.h b/include/linux/usb.h index 8fa9a93a4ec4..5483cd70390b 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1369,6 +1369,7 @@ extern int usb_unlink_urb(struct urb *urb); extern void usb_kill_urb(struct urb *urb); extern void usb_poison_urb(struct urb *urb); extern void usb_unpoison_urb(struct urb *urb); +extern void usb_block_urb(struct urb *urb); extern void usb_kill_anchored_urbs(struct usb_anchor *anchor); extern void usb_poison_anchored_urbs(struct usb_anchor *anchor); extern void usb_unpoison_anchored_urbs(struct usb_anchor *anchor); @@ -1381,6 +1382,8 @@ extern struct urb *usb_get_from_anchor(struct usb_anchor *anchor); extern void usb_scuttle_anchored_urbs(struct usb_anchor *anchor); extern int usb_anchor_empty(struct usb_anchor *anchor); +#define usb_unblock_urb usb_unpoison_urb + /** * usb_urb_dir_in - check if an URB describes an IN transfer * @urb: URB to be checked -- cgit v1.2.3-59-g8ed1b