HID: fix waitqueue usage in hiddev

DECLARE_WAITQUEUE doesn't initialize the wait descriptor's task_list
to 'empty' but to zero.

prepare_to_wait() will not enqueue the descriptor to the waitqueue and
finish_wait() will do list_del_init() on a list head that contains
NULL pointers, which oopses.

This was introduced by 079034073 "HID: hiddev cleanup -- handle all
error conditions properly".

The prior code used an unconditional add_to_waitqueue() which didn't
care about the wait descriptor's list head and enqueued the thing
unconditionally.

The new code uses prepare_to_wait() which DOES check the prior list
state, so use DEFINE_WAIT instead.

Signed-off-by: Johannes Weiner <[email protected]>
Cc: Oliver Neukum <[email protected]>
Cc: Jiri Kosina <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>

0 files changed, 0 insertions, 0 deletions