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 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