Cause
During a read(2), getmsg(2), or ioctl(2) I_RECVFD call to a STREAMS device, some data has come to the head of the queue
that cannot be processed. That data depends on the call:
-
read(2) -- Controls information or passes a file descriptor
-
getmsg(2) -- Passes a file descriptor
-
ioctl(2) -- Controls data information