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| author | Oliver Neukum <oliver@neukum.org> | 2012-04-30 09:13:46 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-05-01 13:22:13 -0400 |
| commit | 8815bb09af21316aeb5f8948b24ac62181670db2 (patch) | |
| tree | a6667e719e124f06257f1b9cb11abe6bce9295b0 /include/linux/usb.h | |
| parent | 166cb70e97bd83d7ae9bbec6ae59a178fd9bb823 (diff) | |
| download | lwn-8815bb09af21316aeb5f8948b24ac62181670db2.tar.gz lwn-8815bb09af21316aeb5f8948b24ac62181670db2.zip | |
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 <oneukum@suse.de>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/usb.h')
| -rw-r--r-- | include/linux/usb.h | 3 |
1 files changed, 3 insertions, 0 deletions
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 |