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| author | Johannes Weiner <hannes@cmpxchg.org> | 2009-03-10 22:44:01 +0100 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2009-03-10 22:44:01 +0100 |
| commit | 96fe2ab830d7dffee1b3d8abf27ced4d7d5765e7 (patch) | |
| tree | f59b1549ecf9fe5e2c5adafc77d16aa36942e07d /drivers | |
| parent | 48e7a3c95c9f98c2cb6f894820e3cc2d0448e92f (diff) | |
| download | linux-96fe2ab830d7dffee1b3d8abf27ced4d7d5765e7.tar.bz2 | |
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 <hannes@cmpxchg.org>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/hid/usbhid/hiddev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c index 00ea1ed282a9..1f5b5d4c3c34 100644 --- a/drivers/hid/usbhid/hiddev.c +++ b/drivers/hid/usbhid/hiddev.c @@ -323,7 +323,7 @@ static ssize_t hiddev_write(struct file * file, const char __user * buffer, size */ static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos) { - DECLARE_WAITQUEUE(wait, current); + DEFINE_WAIT(wait); struct hiddev_list *list = file->private_data; int event_size; int retval; |