diff --git a/sys/alpha/alpha/machdep.c b/sys/alpha/alpha/machdep.c
index 8123ec29ed2d..34dcfe0cf0a7 100644
--- a/sys/alpha/alpha/machdep.c
+++ b/sys/alpha/alpha/machdep.c
@@ -1225,6 +1225,7 @@ DELAY(int n)
  * frame pointer, it returns to the user
  * specified pc, psl.
  */
+#ifdef COMPAT_43
 void
 osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 {
@@ -1329,6 +1330,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	frame->tf_regs[FRAME_T12] = (u_int64_t)catcher;	/* t12 is pv */
 	alpha_pal_wrusp((unsigned long)sip);
 }
+#endif
 
 void
 sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
@@ -1341,10 +1343,12 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 
 	PROC_LOCK(p);
 	psp = p->p_sigacts;
+#ifdef COMPAT_43
 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
+#endif
 
 	frame = p->p_frame;
 	oonstack = sigonstack(alpha_pal_rdusp());
@@ -1480,6 +1484,7 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
  * make sure that the user has not modified the
  * state to gain improper privileges.
  */
+#ifdef COMPAT_43
 int
 osigreturn(struct proc *p,
 	struct osigreturn_args /* {
@@ -1538,6 +1543,7 @@ osigreturn(struct proc *p,
 	p->p_addr->u_pcb.pcb_fp_control = ksc.sc_fp_control;
 	return (EJUSTRETURN);
 }
+#endif
 
 int
 sigreturn(struct proc *p,
@@ -1549,8 +1555,10 @@ sigreturn(struct proc *p,
 	struct pcb *pcb;
 	unsigned long val;
 
+#ifdef COMPAT_43
 	if (((struct osigcontext*)uap->sigcntxp)->sc_regs[R_ZERO] == 0xACEDBADE)
 		return osigreturn(p, (struct osigreturn_args *)uap);
+#endif
 
 	ucp = uap->sigcntxp;
 	pcb = &p->p_addr->u_pcb;
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index 7bc1d3dffd56..a6423536fe8c 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -154,7 +154,9 @@ SYSCTL_INT(_machdep, OID_AUTO, ispc98, CTLFLAG_RD, &ispc98, 0, "");
 int physmem = 0;
 int cold = 1;
 
+#ifdef COMPAT_43
 static void osendsig __P((sig_t catcher, int sig, sigset_t *mask, u_long code));
+#endif
 
 static int
 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
@@ -416,6 +418,7 @@ cpu_startup(dummy)
  * frame pointer, it returns to the user
  * specified pc, psl.
  */
+#ifdef COMPAT_43
 static void
 osendsig(catcher, sig, mask, code)
 	sig_t catcher;
@@ -560,6 +563,7 @@ osendsig(catcher, sig, mask, code)
 	load_gs(_udatasel);
 	regs->tf_ss = _udatasel;
 }
+#endif
 
 void
 sendsig(catcher, sig, mask, code)
@@ -578,11 +582,13 @@ sendsig(catcher, sig, mask, code)
 	p = curproc;
 	PROC_LOCK(p);
 	psp = p->p_sigacts;
+#ifdef COMPAT_43
 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		PROC_UNLOCK(p);
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
+#endif
 	regs = p->p_frame;
 	oonstack = sigonstack(regs->tf_esp);
 
@@ -719,6 +725,7 @@ sendsig(catcher, sig, mask, code)
  * make sure that the user has not modified the
  * state to gain improper privileges.
  */
+#ifdef COMPAT_43
 int
 osigreturn(p, uap)
 	struct proc *p;
@@ -828,6 +835,7 @@ osigreturn(p, uap)
 	regs->tf_eflags = eflags;
 	return (EJUSTRETURN);
 }
+#endif
 
 int
 sigreturn(p, uap)
@@ -841,11 +849,11 @@ sigreturn(p, uap)
 	int cs, eflags;
 
 	ucp = uap->sigcntxp;
+#ifdef COMPAT_43
 	if (!useracc((caddr_t)ucp, sizeof(struct osigcontext), VM_PROT_READ))
 		return (EFAULT);
 	if (((struct osigcontext *)ucp)->sc_trapno == 0x01d516)
 		return (osigreturn(p, (struct osigreturn_args *)uap));
-
 	/*
 	 * Since ucp is not an osigcontext but a ucontext_t, we have to
 	 * check again if all of it is accessible.  A ucontext_t is
@@ -853,6 +861,7 @@ sigreturn(p, uap)
 	 * being valid for the size of an osigcontext, now check for
 	 * it being valid for a whole, new-style ucontext_t.
 	 */
+#endif
 	if (!useracc((caddr_t)ucp, sizeof(*ucp), VM_PROT_READ))
 		return (EFAULT);
 
diff --git a/sys/i386/i386/machdep.c b/sys/i386/i386/machdep.c
index 7bc1d3dffd56..a6423536fe8c 100644
--- a/sys/i386/i386/machdep.c
+++ b/sys/i386/i386/machdep.c
@@ -154,7 +154,9 @@ SYSCTL_INT(_machdep, OID_AUTO, ispc98, CTLFLAG_RD, &ispc98, 0, "");
 int physmem = 0;
 int cold = 1;
 
+#ifdef COMPAT_43
 static void osendsig __P((sig_t catcher, int sig, sigset_t *mask, u_long code));
+#endif
 
 static int
 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
@@ -416,6 +418,7 @@ cpu_startup(dummy)
  * frame pointer, it returns to the user
  * specified pc, psl.
  */
+#ifdef COMPAT_43
 static void
 osendsig(catcher, sig, mask, code)
 	sig_t catcher;
@@ -560,6 +563,7 @@ osendsig(catcher, sig, mask, code)
 	load_gs(_udatasel);
 	regs->tf_ss = _udatasel;
 }
+#endif
 
 void
 sendsig(catcher, sig, mask, code)
@@ -578,11 +582,13 @@ sendsig(catcher, sig, mask, code)
 	p = curproc;
 	PROC_LOCK(p);
 	psp = p->p_sigacts;
+#ifdef COMPAT_43
 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		PROC_UNLOCK(p);
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
+#endif
 	regs = p->p_frame;
 	oonstack = sigonstack(regs->tf_esp);
 
@@ -719,6 +725,7 @@ sendsig(catcher, sig, mask, code)
  * make sure that the user has not modified the
  * state to gain improper privileges.
  */
+#ifdef COMPAT_43
 int
 osigreturn(p, uap)
 	struct proc *p;
@@ -828,6 +835,7 @@ osigreturn(p, uap)
 	regs->tf_eflags = eflags;
 	return (EJUSTRETURN);
 }
+#endif
 
 int
 sigreturn(p, uap)
@@ -841,11 +849,11 @@ sigreturn(p, uap)
 	int cs, eflags;
 
 	ucp = uap->sigcntxp;
+#ifdef COMPAT_43
 	if (!useracc((caddr_t)ucp, sizeof(struct osigcontext), VM_PROT_READ))
 		return (EFAULT);
 	if (((struct osigcontext *)ucp)->sc_trapno == 0x01d516)
 		return (osigreturn(p, (struct osigreturn_args *)uap));
-
 	/*
 	 * Since ucp is not an osigcontext but a ucontext_t, we have to
 	 * check again if all of it is accessible.  A ucontext_t is
@@ -853,6 +861,7 @@ sigreturn(p, uap)
 	 * being valid for the size of an osigcontext, now check for
 	 * it being valid for a whole, new-style ucontext_t.
 	 */
+#endif
 	if (!useracc((caddr_t)ucp, sizeof(*ucp), VM_PROT_READ))
 		return (EFAULT);
 
diff --git a/sys/ia64/ia64/machdep.c b/sys/ia64/ia64/machdep.c
index f91578232c03..8a6d335c210b 100644
--- a/sys/ia64/ia64/machdep.c
+++ b/sys/ia64/ia64/machdep.c
@@ -898,6 +898,7 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
  * make sure that the user has not modified the
  * state to gain improper privileges.
  */
+#ifdef COMPAT_43
 int
 osigreturn(struct proc *p,
 	struct osigreturn_args /* {
@@ -906,6 +907,7 @@ osigreturn(struct proc *p,
 {
 	return EOPNOTSUPP;
 }
+#endif
 
 /*
  * System call to cleanup state after a signal
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 4784e40a06db..0ab24e6a7786 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -326,11 +326,13 @@ do_sigaction(p, sig, act, oact, old)
 			else
 				SIGADDSET(p->p_sigcatch, sig);
 		}
+#ifdef COMPAT_43
 		if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN ||
 		    ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || !old)
 			SIGDELSET(ps->ps_osigset, sig);
 		else
 			SIGADDSET(ps->ps_osigset, sig);
+#endif
 	}
 	PROC_UNLOCK(p);
 	return (0);
diff --git a/sys/pc98/i386/machdep.c b/sys/pc98/i386/machdep.c
index 48eef4944f1c..698a770c5680 100644
--- a/sys/pc98/i386/machdep.c
+++ b/sys/pc98/i386/machdep.c
@@ -164,7 +164,9 @@ SYSCTL_INT(_machdep, OID_AUTO, ispc98, CTLFLAG_RD, &ispc98, 0, "");
 int physmem = 0;
 int cold = 1;
 
+#ifdef COMPAT_43
 static void osendsig __P((sig_t catcher, int sig, sigset_t *mask, u_long code));
+#endif
 
 static int
 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
@@ -420,6 +422,7 @@ cpu_startup(dummy)
  * frame pointer, it returns to the user
  * specified pc, psl.
  */
+#ifdef COMPAT_43
 static void
 osendsig(catcher, sig, mask, code)
 	sig_t catcher;
@@ -564,6 +567,7 @@ osendsig(catcher, sig, mask, code)
 	load_gs(_udatasel);
 	regs->tf_ss = _udatasel;
 }
+#endif
 
 void
 sendsig(catcher, sig, mask, code)
@@ -582,11 +586,13 @@ sendsig(catcher, sig, mask, code)
 	p = curproc;
 	PROC_LOCK(p);
 	psp = p->p_sigacts;
+#ifdef COMPAT_43
 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		PROC_UNLOCK(p);
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
+#endif
 	regs = p->p_frame;
 	oonstack = sigonstack(regs->tf_esp);
 
@@ -723,6 +729,7 @@ sendsig(catcher, sig, mask, code)
  * make sure that the user has not modified the
  * state to gain improper privileges.
  */
+#ifdef COMPAT_43
 int
 osigreturn(p, uap)
 	struct proc *p;
@@ -831,6 +838,7 @@ osigreturn(p, uap)
 	regs->tf_eflags = eflags;
 	return (EJUSTRETURN);
 }
+#endif
 
 int
 sigreturn(p, uap)
@@ -844,11 +852,11 @@ sigreturn(p, uap)
 	int cs, eflags;
 
 	ucp = uap->sigcntxp;
+#ifdef COMPAT_43
 	if (!useracc((caddr_t)ucp, sizeof(struct osigcontext), VM_PROT_READ))
 		return (EFAULT);
 	if (((struct osigcontext *)ucp)->sc_trapno == 0x01d516)
 		return (osigreturn(p, (struct osigreturn_args *)uap));
-
 	/*
 	 * Since ucp is not an osigcontext but a ucontext_t, we have to
 	 * check again if all of it is accessible.  A ucontext_t is
@@ -858,6 +866,7 @@ sigreturn(p, uap)
 	 */
 	if (!useracc((caddr_t)ucp, sizeof(*ucp), VM_PROT_READ))
 		return (EFAULT);
+#endif
 
 	regs = p->p_frame;
 	eflags = ucp->uc_mcontext.mc_eflags;
diff --git a/sys/pc98/pc98/machdep.c b/sys/pc98/pc98/machdep.c
index 48eef4944f1c..698a770c5680 100644
--- a/sys/pc98/pc98/machdep.c
+++ b/sys/pc98/pc98/machdep.c
@@ -164,7 +164,9 @@ SYSCTL_INT(_machdep, OID_AUTO, ispc98, CTLFLAG_RD, &ispc98, 0, "");
 int physmem = 0;
 int cold = 1;
 
+#ifdef COMPAT_43
 static void osendsig __P((sig_t catcher, int sig, sigset_t *mask, u_long code));
+#endif
 
 static int
 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
@@ -420,6 +422,7 @@ cpu_startup(dummy)
  * frame pointer, it returns to the user
  * specified pc, psl.
  */
+#ifdef COMPAT_43
 static void
 osendsig(catcher, sig, mask, code)
 	sig_t catcher;
@@ -564,6 +567,7 @@ osendsig(catcher, sig, mask, code)
 	load_gs(_udatasel);
 	regs->tf_ss = _udatasel;
 }
+#endif
 
 void
 sendsig(catcher, sig, mask, code)
@@ -582,11 +586,13 @@ sendsig(catcher, sig, mask, code)
 	p = curproc;
 	PROC_LOCK(p);
 	psp = p->p_sigacts;
+#ifdef COMPAT_43
 	if (SIGISMEMBER(psp->ps_osigset, sig)) {
 		PROC_UNLOCK(p);
 		osendsig(catcher, sig, mask, code);
 		return;
 	}
+#endif
 	regs = p->p_frame;
 	oonstack = sigonstack(regs->tf_esp);
 
@@ -723,6 +729,7 @@ sendsig(catcher, sig, mask, code)
  * make sure that the user has not modified the
  * state to gain improper privileges.
  */
+#ifdef COMPAT_43
 int
 osigreturn(p, uap)
 	struct proc *p;
@@ -831,6 +838,7 @@ osigreturn(p, uap)
 	regs->tf_eflags = eflags;
 	return (EJUSTRETURN);
 }
+#endif
 
 int
 sigreturn(p, uap)
@@ -844,11 +852,11 @@ sigreturn(p, uap)
 	int cs, eflags;
 
 	ucp = uap->sigcntxp;
+#ifdef COMPAT_43
 	if (!useracc((caddr_t)ucp, sizeof(struct osigcontext), VM_PROT_READ))
 		return (EFAULT);
 	if (((struct osigcontext *)ucp)->sc_trapno == 0x01d516)
 		return (osigreturn(p, (struct osigreturn_args *)uap));
-
 	/*
 	 * Since ucp is not an osigcontext but a ucontext_t, we have to
 	 * check again if all of it is accessible.  A ucontext_t is
@@ -858,6 +866,7 @@ sigreturn(p, uap)
 	 */
 	if (!useracc((caddr_t)ucp, sizeof(*ucp), VM_PROT_READ))
 		return (EFAULT);
+#endif
 
 	regs = p->p_frame;
 	eflags = ucp->uc_mcontext.mc_eflags;
diff --git a/sys/powerpc/aim/machdep.c b/sys/powerpc/aim/machdep.c
index 586210b9466f..cbd8fd2828c7 100644
--- a/sys/powerpc/aim/machdep.c
+++ b/sys/powerpc/aim/machdep.c
@@ -142,7 +142,9 @@ int		restore_ofw_mapping(void);
 
 void		install_extint(void (*)(void));
 
+#ifdef COMPAT_43
 void		osendsig(sig_t, int, sigset_t *, u_long);
+#endif
 
 struct msgbuf	*msgbufp = 0;
 
@@ -789,6 +791,7 @@ delay(unsigned n)
 }
 #endif
 
+#ifdef COMPAT_43
 void
 osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 {
@@ -796,6 +799,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	/* XXX: To be done */
 	return;
 }
+#endif
 
 void
 sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
@@ -805,6 +809,7 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	return;
 }
 
+#ifdef COMPAT_43
 int
 osigreturn(struct proc *p, struct osigreturn_args *uap)
 {
@@ -812,6 +817,7 @@ osigreturn(struct proc *p, struct osigreturn_args *uap)
 	/* XXX: To be done */
 	return(ENOSYS);
 }
+#endif
 
 int
 sigreturn(struct proc *p, struct sigreturn_args *uap)
diff --git a/sys/powerpc/powerpc/machdep.c b/sys/powerpc/powerpc/machdep.c
index 586210b9466f..cbd8fd2828c7 100644
--- a/sys/powerpc/powerpc/machdep.c
+++ b/sys/powerpc/powerpc/machdep.c
@@ -142,7 +142,9 @@ int		restore_ofw_mapping(void);
 
 void		install_extint(void (*)(void));
 
+#ifdef COMPAT_43
 void		osendsig(sig_t, int, sigset_t *, u_long);
+#endif
 
 struct msgbuf	*msgbufp = 0;
 
@@ -789,6 +791,7 @@ delay(unsigned n)
 }
 #endif
 
+#ifdef COMPAT_43
 void
 osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 {
@@ -796,6 +799,7 @@ osendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	/* XXX: To be done */
 	return;
 }
+#endif
 
 void
 sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
@@ -805,6 +809,7 @@ sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
 	return;
 }
 
+#ifdef COMPAT_43
 int
 osigreturn(struct proc *p, struct osigreturn_args *uap)
 {
@@ -812,6 +817,7 @@ osigreturn(struct proc *p, struct osigreturn_args *uap)
 	/* XXX: To be done */
 	return(ENOSYS);
 }
+#endif
 
 int
 sigreturn(struct proc *p, struct sigreturn_args *uap)