Add a global sx sigio_lock to protect the pointer to the sigio object

of a socket.  This avoids lock order reversal caused by locking a
process in pgsigio().

sowakeup() and the callers of it (sowwakeup, soisconnected, etc.) now
require sigio_lock to be locked.  Provide sowwakeup_locked(),
soisconnected_locked(), and so on in case where we have to modify a
socket and wake up a process atomically.

1 files changed, 3 insertions, 1 deletions

diff --git a/sys/netkey/keysock.c b/sys/netkey/keysock.c
index 6d00e48..5b733cd73 100644
--- a/sys/netkey/keysock.c
+++ b/sys/netkey/keysock.c
@@ -428,8 +428,10 @@ key_attach(struct socket *so, int proto, struct thread *td)
 	key_cb.any_count++;
 	kp->kp_raw.rcb_laddr = &key_src;
 	kp->kp_raw.rcb_faddr = &key_dst;
-	soisconnected(so);
+	SIGIO_SLOCK();
+	soisconnected_locked(so);
 	so->so_options |= SO_USELOOPBACK;
+	SIGIO_SUNLOCK();
 
 	splx(s);
 	return 0;