tree 733646ed67e9d39e4cdec59f4ed1ee08d46fc63a
parent bd829e9d1d7de3178d67d94043f43527213a63a0
author Chris Rankin <rankincj@yahoo.com> 1316872952 -0300
committer Mauro Carvalho Chehab <mchehab@redhat.com> 1316877168 -0300

[media] em28xx: fix race on disconnect

This patch closes the race on the device and extension lists at USB disconnect
time. Previously, the device was removed from the device list during
em28xx_release_resources(), and then passed to the em28xx_close_extension()
function so that all extensions could run their fini() operations. However, this
left a (brief, theoretical, highly unlikely ;-)) window between these two calls
during which a new module could call em28xx_register_extension(). The result
would have been that the em28xx_usb_disconnect() function would also have passed
the device to the new extension's fini() function, despite never having called
the extension's init() function.

This patch also restores em28xx_close_extension()'s symmetry with
em28xx_init_extension(), and establishes the property that every device in the
device list must have been initialised for every extension in the extension list.

Signed-off-by: Chris Rankin <rankincj@yahoo.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>