Redo the sigio locking.

Turn the sigio sx into a mutex.

Sigio lock is really only needed to protect interrupts from dereferencing
the sigio pointer in an object when the sigio itself is being destroyed.

In order to do this in the most unintrusive manner change pgsigio's
sigio * argument into a **, that way we can lock internally to the
function.

19 files changed, 42 insertions, 115 deletions

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 13b91ad..425cb39 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -63,6 +63,7 @@
 #include <sys/event.h>
 #include <sys/sx.h>
 #include <sys/socketvar.h>
+#include <sys/signalvar.h>
 
 #include <machine/limits.h>
 
@@ -113,7 +114,7 @@ struct filelist filehead;	/* head of list of open files */
 int nfiles;			/* actual number of open files */
 extern int cmask;	
 struct sx filelist_lock;	/* sx to protect filelist */
-struct sx sigio_lock;		/* sx to protect pointers to sigio */
+struct mtx sigio_lock;		/* mtx to protect pointers to sigio */
 
 /*
  * System calls on descriptors.
@@ -536,14 +537,14 @@ void
 funsetown(sigio)
 	struct sigio *sigio;
 {
-	int s;
 
-	if (sigio == NULL)
+	SIGIO_LOCK();
+	if (sigio == NULL) {
+		SIGIO_UNLOCK();
 		return;
-
-	s = splhigh();
+	}
 	*(sigio->sio_myref) = NULL;
-	splx(s);
+	SIGIO_UNLOCK();
 	if ((sigio)->sio_pgid < 0) {
 		struct pgrp *pg = (sigio)->sio_pgrp;
 		PGRP_LOCK(pg);
@@ -566,7 +567,6 @@ void
 funsetownlst(sigiolst)
 	struct sigiolst *sigiolst;
 {
-	int s;
 	struct sigio *sigio;
 	struct proc *p;
 	struct pgrp *pg;
@@ -591,9 +591,9 @@ funsetownlst(sigiolst)
 	}
 
 	while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
-		s = splhigh();
+		SIGIO_LOCK();
 		*(sigio->sio_myref) = NULL;
-		splx(s);
+		SIGIO_UNLOCK();
 		if (pg != NULL) {
 			KASSERT(sigio->sio_pgid < 0, ("Proc sigio in pgrp sigio list"));
 			KASSERT(sigio->sio_pgrp == pg, ("Bogus pgrp in sigio list"));
@@ -632,7 +632,7 @@ fsetown(pgid, sigiop)
 	struct proc *proc;
 	struct pgrp *pgrp;
 	struct sigio *sigio;
-	int s, ret;
+	int ret;
 
 	if (pgid == 0) {
 		funsetown(*sigiop);
@@ -706,9 +706,9 @@ fsetown(pgid, sigiop)
 		PGRP_UNLOCK(pgrp);
 	}
 	sx_sunlock(&proctree_lock);
-	s = splhigh();
+	SIGIO_LOCK();
 	*sigiop = sigio;
-	splx(s);
+	SIGIO_UNLOCK();
 	return (0);
 
 fail:
@@ -2187,5 +2187,5 @@ filelistinit(dummy)
 	    NULL, NULL, UMA_ALIGN_PTR, 0);
 
 	sx_init(&filelist_lock, "filelist lock");
-	sx_init(&sigio_lock, "sigio lock");
+	mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
 }
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 16c6fed..4c1b683 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -2087,13 +2087,18 @@ nosys(td, args)
  * stored credentials rather than those of the current process.
  */
 void
-pgsigio(sigio, sig, checkctty)
-	struct sigio *sigio;
+pgsigio(sigiop, sig, checkctty)
+	struct sigio **sigiop;
 	int sig, checkctty;
 {
-	if (sigio == NULL)
-		return;
+	struct sigio *sigio;
 
+	SIGIO_LOCK();
+	sigio = *sigiop;
+	if (sigio == NULL) {
+		SIGIO_UNLOCK();
+		return;
+	}
 	if (sigio->sio_pgid > 0) {
 		PROC_LOCK(sigio->sio_proc);
 		if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred))
@@ -2112,6 +2117,7 @@ pgsigio(sigio, sig, checkctty)
 		}
 		PGRP_UNLOCK(sigio->sio_pgrp);
 	}
+	SIGIO_UNLOCK();
 }
 
 static int
diff --git a/sys/kern/subr_log.c b/sys/kern/subr_log.c
index b495a79..568b3fe 100644
--- a/sys/kern/subr_log.c
+++ b/sys/kern/subr_log.c
@@ -198,7 +198,7 @@ logtimeout(void *arg)
 	msgbuftrigger = 0;
 	selwakeup(&logsoftc.sc_selp);
 	if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL)
-		pgsigio(logsoftc.sc_sigio, SIGIO, 0);
+		pgsigio(&logsoftc.sc_sigio, SIGIO, 0);
 	if (logsoftc.sc_state & LOG_RDWAIT) {
 		wakeup((caddr_t)msgbufp);
 		logsoftc.sc_state &= ~LOG_RDWAIT;
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c
index c671c94..d0682fa 100644
--- a/sys/kern/sys_pipe.c
+++ b/sys/kern/sys_pipe.c
@@ -429,7 +429,7 @@ pipeselwakeup(cpipe)
 		selwakeup(&cpipe->pipe_sel);
 	}
 	if ((cpipe->pipe_state & PIPE_ASYNC) && cpipe->pipe_sigio)
-		pgsigio(cpipe->pipe_sigio, SIGIO, 0);
+		pgsigio(&cpipe->pipe_sigio, SIGIO, 0);
 	KNOTE(&cpipe->pipe_sel.si_note, 0);
 }
 
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 6e4ca18..7b3459a 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -2289,7 +2289,7 @@ ttwakeup(tp)
 	if (SEL_WAITING(&tp->t_rsel))
 		selwakeup(&tp->t_rsel);
 	if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
-		pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
+		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 	wakeup(TSA_HUP_OR_INPUT(tp));
 	KNOTE(&tp->t_rsel.si_note, 0);
 }
@@ -2305,7 +2305,7 @@ ttwwakeup(tp)
 	if (SEL_WAITING(&tp->t_wsel) && tp->t_outq.c_cc <= tp->t_olowat)
 		selwakeup(&tp->t_wsel);
 	if (ISSET(tp->t_state, TS_ASYNC) && tp->t_sigio != NULL)
-		pgsigio(tp->t_sigio, SIGIO, (tp->t_session != NULL));
+		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
 	if (ISSET(tp->t_state, TS_BUSY | TS_SO_OCOMPLETE) ==
 	    TS_SO_OCOMPLETE && tp->t_outq.c_cc == 0) {
 		CLR(tp->t_state, TS_SO_OCOMPLETE);
diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c
index cb0a682..91cb57b 100644
--- a/sys/kern/uipc_sockbuf.c
+++ b/sys/kern/uipc_sockbuf.c
@@ -52,7 +52,6 @@
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/stat.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 
@@ -113,7 +112,6 @@ soisconnected_locked(so)
 {
 	struct socket *head = so->so_head;
 
-	SIGIO_ASSERT(SX_SLOCKED); /* XXX */
 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
 	so->so_state |= SS_ISCONNECTED;
 	if (head && (so->so_state & SS_INCOMP)) {
@@ -122,9 +120,7 @@ soisconnected_locked(so)
 			so->so_upcallarg = head->so_accf->so_accept_filter_arg;
 			so->so_rcv.sb_flags |= SB_UPCALL;
 			so->so_options &= ~SO_ACCEPTFILTER;
-			SIGIO_SUNLOCK(); /* XXX */
 			so->so_upcall(so, so->so_upcallarg, 0);
-			SIGIO_SLOCK();
 			return;
 		}
 		TAILQ_REMOVE(&head->so_incomp, so, so_list);
@@ -147,7 +143,6 @@ soisconnected(so)
 {
 	struct socket *head = so->so_head;
 
-	SIGIO_SLOCK();
 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
 	so->so_state |= SS_ISCONNECTED;
 	if (head && (so->so_state & SS_INCOMP)) {
@@ -156,7 +151,6 @@ soisconnected(so)
 			so->so_upcallarg = head->so_accf->so_accept_filter_arg;
 			so->so_rcv.sb_flags |= SB_UPCALL;
 			so->so_options &= ~SO_ACCEPTFILTER;
-			SIGIO_SUNLOCK();
 			so->so_upcall(so, so->so_upcallarg, 0);
 			return;
 		}
@@ -173,7 +167,6 @@ soisconnected(so)
 		sorwakeup_locked(so);
 		sowwakeup_locked(so);
 	}
-	SIGIO_SUNLOCK();
 }
 
 void
@@ -181,13 +174,11 @@ soisdisconnecting(so)
 	register struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	so->so_state &= ~SS_ISCONNECTING;
 	so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
 	wakeup((caddr_t)&so->so_timeo);
 	sowwakeup_locked(so);
 	sorwakeup_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 void
@@ -195,7 +186,6 @@ soisdisconnected_locked(so)
 	register struct socket *so;
 {
 
-	SIGIO_ASSERT(SX_LOCKED);
 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
 	so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
 	wakeup((caddr_t)&so->so_timeo);
@@ -208,9 +198,7 @@ soisdisconnected(so)
 	register struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	soisdisconnected_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 /*
@@ -266,9 +254,7 @@ sonewconn(head, connstatus)
 		head->so_incqlen++;
 	}
 	if (connstatus) {
-		SIGIO_SLOCK();
 		sorwakeup_locked(head);
-		SIGIO_SUNLOCK();
 		wakeup((caddr_t)&head->so_timeo);
 		so->so_state |= connstatus;
 	}
@@ -290,10 +276,8 @@ socantsendmore(so)
 	struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	so->so_state |= SS_CANTSENDMORE;
 	sowwakeup_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 void
@@ -301,10 +285,8 @@ socantrcvmore(so)
 	struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	so->so_state |= SS_CANTRCVMORE;
 	sorwakeup_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 /*
@@ -353,7 +335,6 @@ sowakeup(so, sb)
 	register struct socket *so;
 	register struct sockbuf *sb;
 {
-	SIGIO_ASSERT(SX_LOCKED);
 
 	selwakeup(&sb->sb_sel);
 	sb->sb_flags &= ~SB_SEL;
@@ -362,7 +343,7 @@ sowakeup(so, sb)
 		wakeup((caddr_t)&sb->sb_cc);
 	}
 	if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
-		pgsigio(so->so_sigio, SIGIO, 0);
+		pgsigio(&so->so_sigio, SIGIO, 0);
 	if (sb->sb_flags & SB_UPCALL)
 		(*so->so_upcall)(so, so->so_upcallarg, M_DONTWAIT);
 	if (sb->sb_flags & SB_AIO)
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 0e0fbd9..33f8a4d 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1527,7 +1527,7 @@ sohasoutofband(so)
 	register struct socket *so;
 {
 	if (so->so_sigio != NULL)
-		pgsigio(so->so_sigio, SIGURG, 0);
+		pgsigio(&so->so_sigio, SIGURG, 0);
 	selwakeup(&so->so_rcv.sb_sel);
 }
 
diff --git a/sys/kern/uipc_socket2.c b/sys/kern/uipc_socket2.c
index cb0a682..91cb57b 100644
--- a/sys/kern/uipc_socket2.c
+++ b/sys/kern/uipc_socket2.c
@@ -52,7 +52,6 @@
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/stat.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 
@@ -113,7 +112,6 @@ soisconnected_locked(so)
 {
 	struct socket *head = so->so_head;
 
-	SIGIO_ASSERT(SX_SLOCKED); /* XXX */
 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
 	so->so_state |= SS_ISCONNECTED;
 	if (head && (so->so_state & SS_INCOMP)) {
@@ -122,9 +120,7 @@ soisconnected_locked(so)
 			so->so_upcallarg = head->so_accf->so_accept_filter_arg;
 			so->so_rcv.sb_flags |= SB_UPCALL;
 			so->so_options &= ~SO_ACCEPTFILTER;
-			SIGIO_SUNLOCK(); /* XXX */
 			so->so_upcall(so, so->so_upcallarg, 0);
-			SIGIO_SLOCK();
 			return;
 		}
 		TAILQ_REMOVE(&head->so_incomp, so, so_list);
@@ -147,7 +143,6 @@ soisconnected(so)
 {
 	struct socket *head = so->so_head;
 
-	SIGIO_SLOCK();
 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
 	so->so_state |= SS_ISCONNECTED;
 	if (head && (so->so_state & SS_INCOMP)) {
@@ -156,7 +151,6 @@ soisconnected(so)
 			so->so_upcallarg = head->so_accf->so_accept_filter_arg;
 			so->so_rcv.sb_flags |= SB_UPCALL;
 			so->so_options &= ~SO_ACCEPTFILTER;
-			SIGIO_SUNLOCK();
 			so->so_upcall(so, so->so_upcallarg, 0);
 			return;
 		}
@@ -173,7 +167,6 @@ soisconnected(so)
 		sorwakeup_locked(so);
 		sowwakeup_locked(so);
 	}
-	SIGIO_SUNLOCK();
 }
 
 void
@@ -181,13 +174,11 @@ soisdisconnecting(so)
 	register struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	so->so_state &= ~SS_ISCONNECTING;
 	so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
 	wakeup((caddr_t)&so->so_timeo);
 	sowwakeup_locked(so);
 	sorwakeup_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 void
@@ -195,7 +186,6 @@ soisdisconnected_locked(so)
 	register struct socket *so;
 {
 
-	SIGIO_ASSERT(SX_LOCKED);
 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
 	so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
 	wakeup((caddr_t)&so->so_timeo);
@@ -208,9 +198,7 @@ soisdisconnected(so)
 	register struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	soisdisconnected_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 /*
@@ -266,9 +254,7 @@ sonewconn(head, connstatus)
 		head->so_incqlen++;
 	}
 	if (connstatus) {
-		SIGIO_SLOCK();
 		sorwakeup_locked(head);
-		SIGIO_SUNLOCK();
 		wakeup((caddr_t)&head->so_timeo);
 		so->so_state |= connstatus;
 	}
@@ -290,10 +276,8 @@ socantsendmore(so)
 	struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	so->so_state |= SS_CANTSENDMORE;
 	sowwakeup_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 void
@@ -301,10 +285,8 @@ socantrcvmore(so)
 	struct socket *so;
 {
 
-	SIGIO_SLOCK();
 	so->so_state |= SS_CANTRCVMORE;
 	sorwakeup_locked(so);
-	SIGIO_SUNLOCK();
 }
 
 /*
@@ -353,7 +335,6 @@ sowakeup(so, sb)
 	register struct socket *so;
 	register struct sockbuf *sb;
 {
-	SIGIO_ASSERT(SX_LOCKED);
 
 	selwakeup(&sb->sb_sel);
 	sb->sb_flags &= ~SB_SEL;
@@ -362,7 +343,7 @@ sowakeup(so, sb)
 		wakeup((caddr_t)&sb->sb_cc);
 	}
 	if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
-		pgsigio(so->so_sigio, SIGIO, 0);
+		pgsigio(&so->so_sigio, SIGIO, 0);
 	if (sb->sb_flags & SB_UPCALL)
 		(*so->so_upcall)(so, so->so_upcallarg, M_DONTWAIT);
 	if (sb->sb_flags & SB_AIO)
diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index 0077e51..325af54 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -511,7 +511,7 @@ bpf_wakeup(d)
 	}
 	wakeup((caddr_t)d);
 	if (d->bd_async && d->bd_sig && d->bd_sigio)
-		pgsigio(d->bd_sigio, d->bd_sig, 0);
+		pgsigio(&d->bd_sigio, d->bd_sig, 0);
 
 	selwakeup(&d->bd_sel);
 }
diff --git a/sys/net/if_tap.c b/sys/net/if_tap.c
index ad2ba05..45ce21f 100644
--- a/sys/net/if_tap.c
+++ b/sys/net/if_tap.c
@@ -626,7 +626,7 @@ tapifstart(ifp)
 		}
 
 		if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL))
-			pgsigio(tp->tap_sigio, SIGIO, 0);
+			pgsigio(&tp->tap_sigio, SIGIO, 0);
 
 		selwakeup(&tp->tap_rsel);
 		ifp->if_opackets ++; /* obytes are counted in ether_output */
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index b6c7668..a6c89fb 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -223,7 +223,7 @@ tunstart(struct ifnet *ifp)
 		wakeup((caddr_t)tp);
 	}
 	if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
-		pgsigio(tp->tun_sigio, SIGIO, 0);
+		pgsigio(&tp->tun_sigio, SIGIO, 0);
 	selwakeup(&tp->tun_rsel);
 }
 
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 11481fe..47031c2 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -39,7 +39,6 @@
 #include <sys/domain.h>
 #include <sys/kernel.h>
 #include <sys/jail.h>
-#include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/proc.h>
@@ -47,7 +46,6 @@
 #include <sys/signalvar.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 
@@ -149,10 +147,8 @@ rts_attach(struct socket *so, int proto, struct thread *td)
 	}
 	rp->rcb_faddr = &route_src;
 	route_cb.any_count++;
-	SIGIO_SLOCK();
 	soisconnected_locked(so);
 	so->so_options |= SO_USELOOPBACK;
-	SIGIO_SUNLOCK();
 	splx(s);
 	return 0;
 }
diff --git a/sys/netinet/accf_data.c b/sys/netinet/accf_data.c
index dd710e6..46c92e3 100644
--- a/sys/netinet/accf_data.c
+++ b/sys/netinet/accf_data.c
@@ -30,11 +30,9 @@
 
 #include <sys/param.h>
 #include <sys/kernel.h>
-#include <sys/lock.h>
 #include <sys/sysctl.h>
 #include <sys/signalvar.h>
 #include <sys/socketvar.h>
-#include <sys/sx.h>
 
 /* accept filter that holds a socket until data arrives */
 
@@ -59,15 +57,11 @@ static void
 sohasdata(struct socket *so, void *arg, int waitflag)
 {
 
-	SIGIO_SLOCK();
-	if (!soreadable(so)) {
-		SIGIO_SUNLOCK();
+	if (!soreadable(so))
 		return;
-	}
 
 	so->so_upcall = NULL;
 	so->so_rcv.sb_flags &= ~SB_UPCALL;
 	soisconnected_locked(so);
-	SIGIO_SUNLOCK();
 	return;
 }
diff --git a/sys/netinet/accf_http.c b/sys/netinet/accf_http.c
index 3109174..4a3e17e 100644
--- a/sys/netinet/accf_http.c
+++ b/sys/netinet/accf_http.c
@@ -31,12 +31,10 @@
 
 #include <sys/param.h>
 #include <sys/kernel.h>
-#include <sys/lock.h>
 #include <sys/mbuf.h>
 #include <sys/signalvar.h>
 #include <sys/sysctl.h>
 #include <sys/socketvar.h>
-#include <sys/sx.h>
 
 /* check for GET/HEAD */
 static void sohashttpget(struct socket *so, void *arg, int waitflag);
@@ -203,11 +201,9 @@ sohashttpget(struct socket *so, void *arg, int waitflag)
 
 fallout:
 	DPRINT("fallout");
-	SIGIO_SLOCK();
 	so->so_upcall = NULL;
 	so->so_rcv.sb_flags &= ~SB_UPCALL;
 	soisconnected_locked(so);
-	SIGIO_SUNLOCK();
 	return;
 }
 
@@ -287,11 +283,9 @@ readmore:
 
 fallout:
 	DPRINT("fallout");
-	SIGIO_SLOCK();
 	so->so_upcall = NULL;
 	so->so_rcv.sb_flags &= ~SB_UPCALL;
 	soisconnected_locked(so);
-	SIGIO_SUNLOCK();
 	return;
 }
 
@@ -359,10 +353,8 @@ readmore:
 	return;
 
 gotit:
-	SIGIO_SLOCK();
 	so->so_upcall = NULL;
 	so->so_rcv.sb_flags &= ~SB_UPCALL;
 	soisconnected_locked(so);
-	SIGIO_SUNLOCK();
 	return;
 }
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 2a78e5e..b193327 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -42,7 +42,6 @@
 
 #include <sys/param.h>
 #include <sys/kernel.h>
-#include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/proc.h>		/* for proc0 declaration */
@@ -50,7 +49,6 @@
 #include <sys/signalvar.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/syslog.h>
 #include <sys/systm.h>
@@ -1845,14 +1843,10 @@ process_ACK:
 				 * specification, but if we don't get a FIN
 				 * we'll hang forever.
 				 */
-				SIGIO_SLOCK();
 				if (so->so_state & SS_CANTRCVMORE) {
 					soisdisconnected_locked(so);
-					SIGIO_SUNLOCK();
 					callout_reset(tp->tt_2msl, tcp_maxidle,
 						      tcp_timer_2msl, tp);
-				} else {
-					SIGIO_SUNLOCK();
 				}
 				tp->t_state = TCPS_FIN_WAIT_2;
 			}
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index 2a78e5e..b193327 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -42,7 +42,6 @@
 
 #include <sys/param.h>
 #include <sys/kernel.h>
-#include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/proc.h>		/* for proc0 declaration */
@@ -50,7 +49,6 @@
 #include <sys/signalvar.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/syslog.h>
 #include <sys/systm.h>
@@ -1845,14 +1843,10 @@ process_ACK:
 				 * specification, but if we don't get a FIN
 				 * we'll hang forever.
 				 */
-				SIGIO_SLOCK();
 				if (so->so_state & SS_CANTRCVMORE) {
 					soisdisconnected_locked(so);
-					SIGIO_SUNLOCK();
 					callout_reset(tp->tt_2msl, tcp_maxidle,
 						      tcp_timer_2msl, tp);
-				} else {
-					SIGIO_SUNLOCK();
 				}
 				tp->t_state = TCPS_FIN_WAIT_2;
 			}
diff --git a/sys/netkey/keysock.c b/sys/netkey/keysock.c
index 79e4831..68f1045 100644
--- a/sys/netkey/keysock.c
+++ b/sys/netkey/keysock.c
@@ -39,15 +39,12 @@
 #include <sys/domain.h>
 #include <sys/errno.h>
 #include <sys/kernel.h>
-#include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
-#include <sys/mutex.h>
 #include <sys/protosw.h>
 #include <sys/signalvar.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
-#include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 
@@ -430,10 +427,8 @@ 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;
-	SIGIO_SLOCK();
 	soisconnected_locked(so);
 	so->so_options |= SO_USELOOPBACK;
-	SIGIO_SUNLOCK();
 
 	splx(s);
 	return 0;
diff --git a/sys/sys/signalvar.h b/sys/sys/signalvar.h
index b018252..cd61cff 100644
--- a/sys/sys/signalvar.h
+++ b/sys/sys/signalvar.h
@@ -216,20 +216,20 @@ struct pgrp;
 struct thread;
 struct proc;
 struct sigio;
-struct sx;
+struct mtx;
 
 extern int sugid_coredump;	/* Sysctl variable kern.sugid_coredump */
-extern struct sx	sigio_lock;
+extern struct mtx	sigio_lock;
 
 /*
  * Lock the pointers for a sigio object in the underlying objects of
  * a file descriptor.
  */
-#define SIGIO_SLOCK()	sx_slock(&sigio_lock)
-#define SIGIO_XLOCK()	sx_xlock(&sigio_lock)
-#define SIGIO_SUNLOCK()	sx_sunlock(&sigio_lock)
-#define SIGIO_XUNLOCK()	sx_xunlock(&sigio_lock)
-#define SIGIO_ASSERT(what)	sx_assert(&sigio_lock, what)
+#define SIGIO_LOCK()	mtx_lock(&sigio_lock)
+#define SIGIO_TRYLOCK()	mtx_trylock(&sigio_lock)
+#define SIGIO_UNLOCK()	mtx_unlock(&sigio_lock)
+#define SIGIO_LOCKED()	mtx_owned(&sigio_lock)
+#define SIGIO_ASSERT(type)	mtx_assert(&sigio_lock, type)
 
 /*
  * Machine-independent functions:
@@ -239,7 +239,7 @@ void	execsigs(struct proc *p);
 void	gsignal(int pgid, int sig);
 int	issignal(struct proc *p);
 void	killproc(struct proc *p, char *why);
-void	pgsigio(struct sigio *, int signum, int checkctty);
+void	pgsigio(struct sigio **, int signum, int checkctty);
 void	pgsignal(struct pgrp *pgrp, int sig, int checkctty);
 void	postsig(int sig);
 void	psignal(struct proc *p, int sig);
diff --git a/sys/sys/socketvar.h b/sys/sys/socketvar.h
index 4b765aa..3a2f53c 100644
--- a/sys/sys/socketvar.h
+++ b/sys/sys/socketvar.h
@@ -283,27 +283,21 @@ struct xsocket {
 			} while(0)
 
 #define	sorwakeup_locked(so)	do {						\
-					SIGIO_ASSERT(SX_SLOCKED); /* XXX */	\
 					if (sb_notify(&(so)->so_rcv))		\
 						sowakeup((so), &(so)->so_rcv);	\
 				} while (0)
 
 #define	sorwakeup(so)		do {						\
-					SIGIO_SLOCK();				\
 					sorwakeup_locked(so);			\
-					SIGIO_SUNLOCK();			\
 				} while (0)
 
 #define	sowwakeup_locked(so)	do {						\
-					SIGIO_ASSERT(SX_SLOCKED); /* XXX */	\
 					if (sb_notify(&(so)->so_snd))		\
 						sowakeup((so), &(so)->so_snd);	\
 				} while (0)
 
 #define	sowwakeup(so)		do {						\
-					SIGIO_SLOCK();				\
 					sowwakeup_locked(so);			\
-					SIGIO_SUNLOCK();			\
 				} while (0)
 
 #ifdef _KERNEL