rapidio: avoid data race between file operation callbacks and mport_cdev_add().

Fields of md(mport_dev) are set after cdev_device_add().  However, the
file operation callbacks can be called after cdev_device_add() and
therefore accesses to fields of md in the callbacks can race with the rest
of the mport_cdev_add() function.

One such example is INIT_LIST_HEAD(&md->portwrites) in mport_cdev_add(),
the list is initialised after cdev_device_add().  This can race with
list_add_tail(&pw_filter->md_node,&md->portwrites) in
rio_mport_add_pw_filter() which is called by unlocked_ioctl.

To avoid such data races use cdev_device_add() after initializing md.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Madhuparna Bhowmik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Acked-by: Alexandre Bounine <[email protected]>
Cc: Matt Porter <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Mike Marshall <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Allison Randal <[email protected]>
Cc: Pavel Andrianov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions