Skip to content

L
linux
Switch branch/tag
  1. 20 Dec, 2013 19 commits
  3. 19 Dec, 2013 8 commits
  5. 18 Dec, 2013 9 commits
  7. 17 Dec, 2013 4 commits
    • Bernd Porr's avatar
      staging: comedi: fix result of memdup_user for user chanlist · e56b1401
      Bernd Porr authored 
      If the channel list is not set in userspace we get an error at
PTR_ERR(async->cmd.chanlist). However, do_become_nonbusy(dev, s) cleans
up this pointer which causes a kernel ooops. Setting the channel list in
async to NULL and checking this in do_become_nonbusy prevents the oops.

[Ian Abbott] Also do the same for the chanlist allocated in
do_cmdtest_ioctl().
Signed-off-by: default avatarBernd Porr <mail@berndporr.me.uk>
Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e56b1401
    • Masanari Iida's avatar
      staging: keucr: Fix typo in keucr driver · b163970f
      Masanari Iida authored 
      Correct spelling typo in comment and printk.
Signed-off-by: default avatarMasanari Iida <standby24x7@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b163970f
    • Malcolm Priestley's avatar
      staging: vt6656: clean up CARDbSetMediaChannel. · 7387f438
      Malcolm Priestley authored 
      White space and commented out code.

Camel case clean up.
pDevice -> priv
uConnectionChannel -> connection_channel
Signed-off-by: default avatarMalcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7387f438
    • Ian Abbott's avatar
      staging/comedi: bug fix for module usage count on device removal · 1363e4fb
      Ian Abbott authored 
      When a dynamically created comedi device is being automatically removed
by a call to `comedi_auto_unconfig()` from the lower level driver,
`comedi_device_cleanup()` is called to perform the detachment from the
lower level driver.  If the comedi device is open at the time,
`dev->use_count` will be the the number of outstanding opens.  The
function currently decrements the the module counts of the "comedi"
module and the low-level driver module by this amount and reduces
`dev->use_count` to zero.  There are various problems with this as the
`release` file operation handler `comedi_close()` also decrements
`dev->use_count` and decrements the module usage counts.  This means
that `dev->use_count` and the module counts can end up negative.

Also, the assumed one-to-one relationship between the file open count
and the low-level module usage count is invalid and can get screwed up.
We only want to stop the low-level module being unloaded while a comedi
device using the module has an open file object.

Also, there is no need to manipulate the module count of the core
"comedi" module at all since the comedi module is the owner of the file
operations structure and the system will not unload the module while
there are open file objects using it.

Correct the bugs and simplify as follows:

1. Get rid of the module count manipulations of the core "comedi" module
(`THIS_MODULE`) altogether.

2. Don't alter `dev->use_count` in `comedi_device_cleanup()` as it
should only be altered by the `open` and `release` file operation
handlers `comedi_open()` and `comedi_close()`.

3. Increment the low-level module count for the following reasons:

  a) In `comedi_open()` if the open count was zero and the comedi device
     is attached to the low-level driver.
  b) When the `COMEDI_DEVCONFIG` ioctl is used to manually attach an
     unattached comedi device to a low-level driver.  The open count
     will be greater than zero at this time.  The actual increment of
     the low-level module count is already done by
     `comedi_device_attach()`.

4. Decrement the low-level module count for the following reasons:

  a) In `comedi_close()` if the open count was 1 and the comedi device
     is attached to the low-level driver.
  b) In `comedi_device_cleanup()` (called via `comedi_auto_unconfig()`
     --> `comedi_release_hardware_device()` -->
     `comedi_free_board_dev()` when the comedi device is automatically
     unconfigured due to action by the low-level driver) if the device
     was attached (which it should be) and open count was non-zero
     (greater than zero).
  c) When the `COMEDI_DEVCONFIG` ioctl is used to manually detach the
     comedi device from the low-level driver.  The open count will be
     greater than zero at this time.

The open count should never go negative.  Parts 3 and 4 ensure that the
low-level module usage count is incremented on entering the state where
the comedi device is attached to the low-level driver AND the open count
is greater than zero, and is decremented on leaving that state.
Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1363e4fb
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7