19 files changed, 42 insertions, 115 deletions

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 13b91adecf79..425cb3947152 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 16c6fed05a44..4c1b6837fb0f 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 b495a796cd5e..568b3fe128df 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 c671c9434086..d0682fa0cdb5 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 6e4ca184315d..7b3459acc213 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 cb0a6823d0c2..91cb57b2facb 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 0e0fbd93fbc9..33f8a4dd4c33 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 cb0a6823d0c2..91cb57b2facb 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 0077e51369a1..325af5430cec 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 ad2ba05e8397..45ce21f05868 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 b6c76680a010..a6c89fb01fb8 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 11481fe5fa04..47031c234354 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 dd710e644275..46c92e3a3074 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 310917463776..4a3e17ee0b8e 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 2a78e5e65905..b193327f3197 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 2a78e5e65905..b193327f3197 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 79e4831fe3d8..68f104533aa6 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 b0182527a899..cd61cff1f20d 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 4b765aa2f316..3a2f53c774c0 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