Fix PR kern/185813 "SOCK_SEQPACKET AF_UNIX sockets with asymmetrical buffers
drop packets". It was caused by a check for the space available in a
sockbuf, but it was checking the wrong sockbuf.
sys/sys/sockbuf.h
sys/kern/uipc_sockbuf.c
Add sbappendaddr_nospacecheck_locked(), which is just like
sbappendaddr_locked but doesn't validate the receiving socket's space.
Factor out common code into sbappendaddr_locked_internal(). We
shouldn't simply make sbappendaddr_locked check the space and then call
sbappendaddr_nospacecheck_locked, because that would cause the O(n)
function m_length to be called twice.
sys/kern/uipc_usrreq.c
Use sbappendaddr_nospacecheck_locked for SOCK_SEQPACKET sockets,
because the receiving sockbuf's size limit is irrelevant.
tests/sys/kern/unix_seqpacket_test.c
Now that 185813 is fixed, pipe_128k_8k fails intermittently due to
185812. Make it fail every time by adding a usleep after starting the
writer thread and before starting the reader thread in test_pipe. That
gives the writer time to fill up its send buffer. Also, clear the
expected failure message due to 185813. It actually said "185812", but
that was a typo.
PR: kern/185813
df22d5312e