diff options
author | Ian Abbott <abbotti@mev.co.uk> | 2013-01-28 16:14:31 +0000 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2013-03-06 03:23:46 +0000 |
commit | 6c7050330611973632ce7d73f0e914ed6f63f946 (patch) | |
tree | 5d32af0c5cba5dfc119ce96e88ffd97307d85c1a /sound | |
parent | 39b9d4375b2ccdf7df13f94bbf29a308c90cd03f (diff) |
staging: comedi: disallow COMEDI_DEVCONFIG on non-board minors
commit 754ab5c0e55dd118273ca2c217c4d95e9fbc8259 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'sound')
0 files changed, 0 insertions, 0 deletions