upon further thought this code is still racy.
retval = usb_register_dev(usbhid->intf, &hiddev_class);
here you open a window during which open can happen
if (retval) {
err_hid("Not able to get a minor for this device.");
hid->hiddev = NULL;
kfree(hiddev);
return -1;
} else {
hid->minor = usbhid->intf->minor;
hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
and will fail because hiddev_table hasn't been updated
The obvious fix of using a mutex to guard hiddev_table doesn't work because
usb_open() and usb_register_dev() take minor_rwsem and we'd have an AB-BA
deadlock. We need a lock usb_open() also takes in the right order and that leaves
only one option, BKL. I don't like it but I see no alternative.
Once the usb_open() implements something better than lock_kernel(), we could also
do so.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* 'bkl-removal' of git://git.lwn.net/linux-2.6:
Rationalize fasync return values
Move FASYNC bit handling to f_op->fasync()
Use f_lock to protect f_flags
Rename struct file->f_ep_lock
This uses the USB busy mechanism for aggessive autosuspend of USB
HID devices. It autosuspends all opened devices supporting remote wakeup
after a timeout unless
- output is being done to the device
- a key is being held down (remote wakeup isn't triggered upon key release)
- LED(s) are lit
- hiddev is opened
As in the current driver closed devices will be autosuspended even if they
don't support remote wakeup.
The patch is quite large because output to devices is done in hard interrupt
context meaning a lot a queuing and locking had to be touched. The LED stuff
has been solved by means of a simple counter. Additions to the generic HID code
could be avoided. In addition it now covers hidraw. It contains an embryonic
version of an API to let the generic HID code tell the lower levels which
capabilities with respect to power management are needed.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Most fasync implementations do something like:
return fasync_helper(...);
But fasync_helper() will return a positive value at times - a feature used
in at least one place. Thus, a number of other drivers do:
err = fasync_helper(...);
if (err < 0)
return err;
return 0;
In the interests of consistency and more concise code, it makes sense to
map positive return values onto zero where ->fasync() is called.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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>
If hiddev_open() fails, it wrongly frees the shared hiddev structure
kept in hiddev_table instead of the hiddev_list structure allocated
for the opened file descriptor. Existing references to this structure
will then accessed free memory.
This was introduced by 079034073 "HID: hiddev cleanup -- handle all
error conditions properly".
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>
The logic for testing for disconnection is reversed in an ioctl leading
to false reports of disconnection.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Tested-by: Folkert van Heusden <folkert@vanheusden.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Commit 079034073f ("HID: hiddev cleanup -- handle all error conditions
properly") by mistake removed proper initialization of hid->hiddev pointer
in hiddev_connect() in case usb_register_dev() succeeds for the hiddev node.
Put it properly back in place.
Reported-and-tested-by: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a cleanup of hiddev and fixes the following issues:
- thread safety by locking in read & ioctl, introducing a per device mutex
- race between ioctl and disconnect, introducing a flag and locking
in form of a per low level device mutex
- race between open and other methods, making sure only successfully
opened devices are put on the list, changing order of events
- range checking both upper and lower limits of the minor range
- make sure further calls to open fail for unplugged devices even if
the device still has opened files
- error checking for low level open
- possible loss of wakeup events, using standard waiting macros
- race in initialisation by moving registration after full initialisation
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
As it is, all instances of ->release() for files that have ->fasync()
need to remember to evict file from fasync lists; forgetting that
creates a hole and we actually have a bunch that *does* forget.
So let's keep our lives simple - let __fput() check FASYNC in
file->f_flags and call ->fasync() there if it's been set. And lose that
crap in ->release() instances - leaving it there is still valid, but we
don't have to bother anymore.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move connecting from usbhid to the hid layer and fix also hidp in
that manner.
This removes all the ignore/force hidinput/hiddev connecting quirks.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Fix build failure introduced by Alan's ioctl -> unlocked_ioctl
(pushing BKL down to the driver) conversion patch for hiddev.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Push down the BKL. In some cases compat_ioctl already doesn't take the
BKL so we don't either. Some of the locking here seems already dubious
and object lifetimes want documenting
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Fix build failure in hiddev_ioctl with gcc 3.2:
http://bugzilla.kernel.org/show_bug.cgi?id=10121
The trick is to move the handling of ioctls which need to allocate
memory to separate functions.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
drivers/hid/usbhid/hiddev.c: In function 'hiddev_compat_ioctl':
drivers/hid/usbhid/hiddev.c:746: warning: passing argument 4 of 'hiddev_ioctl' makes
integer from pointer without a cast
Add cast to hiddev_compat_ioctl()
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The hiddev driver currently lacks 32bit ioctl compatibility, so
if you're running with a 64bit kernel and 32bit userspace, it won't
work.
I'm pretty sure that the only thing missing is a compat_ioctl
implementation as all structs have fixed size fields.
With this change I can use revoco to configure my MX Revolution mouse.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There have been many reports recently about broken HID devices, the
diagnosis of which required users to recompile their kernels in order
to be able to provide debugging output needed for coding a quirk for
a particular device.
This patch makes CONFIG_HID_DEBUG default y if !EMBEDDED and makes it
possible to control debugging output produced by HID code by supplying
'debug=1' module parameter.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There is a small race window in which hiddev_release() could corrupt the
list that is being processed for new event in hiddev_send_event().
Synchronize the operations over this list.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Separate usbhid code into dedicated drivers/hid/usbhid directory as
discussed previously with Greg, so that it eases maintaineance process.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Jiri Kosina
Oliver Neukum
Linus Torvalds
Jonathan Corbet
Johannes Weiner
Al Viro
Jiri Slaby
Alan Cox
Jean Delvare
Philip Langdale