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author | Ian Abbott | 2013-01-28 17:14:31 +0100 |
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committer | Greg Kroah-Hartman | 2013-01-30 11:47:47 +0100 |
commit | 754ab5c0e55dd118273ca2c217c4d95e9fbc8259 (patch) | |
tree | 9ad32259cc7428c9762b45bc75b48e1324cc3369 /drivers/cpufreq | |
parent | staging/fwserial: Fix endian issue in unit directory (diff) | |
download | kernel-qcow2-linux-754ab5c0e55dd118273ca2c217c4d95e9fbc8259.tar.gz kernel-qcow2-linux-754ab5c0e55dd118273ca2c217c4d95e9fbc8259.tar.xz kernel-qcow2-linux-754ab5c0e55dd118273ca2c217c4d95e9fbc8259.zip |
staging: comedi: disallow COMEDI_DEVCONFIG on non-board minors
Comedi has two sorts of minor devices:
(a) normal board minor devices in the range 0 to
COMEDI_NUM_BOARD_MINORS-1 inclusive; and
(b) special subdevice minor devices in the range COMEDI_NUM_BOARD_MINORS
upwards that are used to open the same underlying comedi device as the
normal board minor devices, but with non-default read and write
subdevices for asynchronous commands.
The special subdevice minor devices get created when a board supporting
asynchronous commands is attached to a normal board minor device, and
destroyed when the board is detached from the normal board minor device.
One way to attach or detach a board is by using the COMEDI_DEVCONFIG
ioctl. This should only be used on normal board minors as the special
subdevice minors are too ephemeral. In particular, the change
introduced in commit 7d3135af399e92cf4c9bbc5f86b6c140aab3b88c ("staging:
comedi: prevent auto-unconfig of manually configured devices") breaks
horribly for special subdevice minor devices.
Since there's no legitimate use for the COMEDI_DEVCONFIG ioctl on a
special subdevice minor device node, disallow it and return -ENOTTY.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cpufreq')
0 files changed, 0 insertions, 0 deletions