staging: logger: hold mutex while removing reader

The readers list is traversed under the log->mutex lock
(for example from fix_up_readers()), but the deletion of
elements from this list is not being done under this lock.

Change-Id: If042db86e33e49a06aa04260514f84b4f2aaaf0f
Cc: Brian Swetland <swetland@google.com>
Cc: Dima Zavin <dima@android.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add permission checking for binder IPC.

Do not apply permission checks to private files.

Fix security_binder_transfer_binder hook.

Drop the owning task argument to security_binder_transfer_binder
since ref->node->proc can be NULL (dead owner?).
Revise the SELinux checking to apply a single transfer check between
the source and destination tasks.  Owning task is no longer relevant.
Drop the receive permission definition as it is no longer used.

This makes the transfer permission similar to the call permission; it is only
useful if you want to allow a binder IPC between two tasks (call permission)
but deny passing of binder references between them (transfer permission).

Change-Id: I51e7a9a6662e826073b35e4f70a57f9ec73e472e
Signed-off-by: William Roberts <w.roberts@sta.samsung.com>