os/signal: selective signal handling

Restore package os/signal, with new API:
Notify replaces Incoming, allowing clients
to ask for certain signals only.  Also, signals
go to everyone who asks, not just one client.

This could plausibly move into package os now
that there are no magic side effects as a result
of the import.

Update runtime for new API: move common Unix
signal handling code into signal_unix.c.
(It's so easy to do this now that we don't have
to edit Makefiles!)

Tested on darwin,linux 386,amd64.

Fixes #1266.

R=r, dsymonds, bradfitz, iant, borman
CC=golang-dev
https://golang.org/cl/3749041

32 files changed, 539 insertions, 997 deletions

diff --git a/src/pkg/runtime/os_darwin.h b/src/pkg/runtime/os_darwin.h
index 3e96071ba3..0003b66c91 100644
--- a/src/pkg/runtime/os_darwin.h
+++ b/src/pkg/runtime/os_darwin.h
@@ -22,6 +22,8 @@ int32	runtime·sysctl(uint32*, uint32, byte*, uintptr*, byte*, uintptr);
 
 struct Sigaction;
 void	runtime·sigaction(uintptr, struct Sigaction*, struct Sigaction*);
+void	runtime·setsig(int32, void(*)(int32, Siginfo*, void*, G*), bool);
+void	runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp);
 
 struct StackT;
 void	runtime·sigaltstack(struct StackT*, struct StackT*);
@@ -30,3 +32,6 @@ void	runtime·sigpanic(void);
 void	runtime·setitimer(int32, Itimerval*, Itimerval*);
 
 void	runtime·raisesigpipe(void);
+
+#define	NSIG 32
+#define	SI_USER	0  /* empirically true, but not what headers say */
diff --git a/src/pkg/runtime/os_freebsd.h b/src/pkg/runtime/os_freebsd.h
index 8ef4c39877..18adab4554 100644
--- a/src/pkg/runtime/os_freebsd.h
+++ b/src/pkg/runtime/os_freebsd.h
@@ -6,8 +6,12 @@ void	runtime·sigpanic(void);
 void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
 struct	sigaction;
 void	runtime·sigaction(int32, struct sigaction*, struct sigaction*);
+void	runtime·setsig(int32, void(*)(int32, Siginfo*, void*, G*), bool);
 void	runtiem·setitimerval(int32, Itimerval*, Itimerval*);
 void	runtime·setitimer(int32, Itimerval*, Itimerval*);
 int32	runtime·sysctl(uint32*, uint32, byte*, uintptr*, byte*, uintptr);
 
 void	runtime·raisesigpipe(void);
+
+#define	NSIG 33
+#define	SI_USER	0
diff --git a/src/pkg/runtime/os_linux.h b/src/pkg/runtime/os_linux.h
index 0bb8d03392..82498c9888 100644
--- a/src/pkg/runtime/os_linux.h
+++ b/src/pkg/runtime/os_linux.h
@@ -11,9 +11,14 @@ int32	runtime·clone(int32, void*, M*, G*, void(*)(void));
 
 struct Sigaction;
 void	runtime·rt_sigaction(uintptr, struct Sigaction*, void*, uintptr);
+void	runtime·setsig(int32, void(*)(int32, Siginfo*, void*, G*), bool);
+void	runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp);
 
 void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
 void	runtime·sigpanic(void);
 void runtime·setitimer(int32, Itimerval*, Itimerval*);
 
 void	runtime·raisesigpipe(void);
+
+#define	NSIG	65
+#define	SI_USER 0
diff --git a/src/pkg/runtime/os_netbsd.h b/src/pkg/runtime/os_netbsd.h
index cf35402cac..67c58ecb2a 100644
--- a/src/pkg/runtime/os_netbsd.h
+++ b/src/pkg/runtime/os_netbsd.h
@@ -10,8 +10,13 @@ struct sigaction;
 void	runtime·sigpanic(void);
 void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
 void	runtime·sigaction(int32, struct sigaction*, struct sigaction*);
+void	runtime·setsig(int32, void(*)(int32, Siginfo*, void*, G*), bool);
+void	runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp);
 void	runtime·setitimerval(int32, Itimerval*, Itimerval*);
 void	runtime·setitimer(int32, Itimerval*, Itimerval*);
 int32	runtime·sysctl(uint32*, uint32, byte*, uintptr*, byte*, uintptr);
 
 void	runtime·raisesigpipe(void);
+
+#define	NSIG 33
+#define	SI_USER	0
diff --git a/src/pkg/runtime/os_openbsd.h b/src/pkg/runtime/os_openbsd.h
index cf35402cac..67c58ecb2a 100644
--- a/src/pkg/runtime/os_openbsd.h
+++ b/src/pkg/runtime/os_openbsd.h
@@ -10,8 +10,13 @@ struct sigaction;
 void	runtime·sigpanic(void);
 void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
 void	runtime·sigaction(int32, struct sigaction*, struct sigaction*);
+void	runtime·setsig(int32, void(*)(int32, Siginfo*, void*, G*), bool);
+void	runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp);
 void	runtime·setitimerval(int32, Itimerval*, Itimerval*);
 void	runtime·setitimer(int32, Itimerval*, Itimerval*);
 int32	runtime·sysctl(uint32*, uint32, byte*, uintptr*, byte*, uintptr);
 
 void	runtime·raisesigpipe(void);
+
+#define	NSIG 33
+#define	SI_USER	0
diff --git a/src/pkg/runtime/runtime.c b/src/pkg/runtime/runtime.c
index 81caccad31..afe8c5abeb 100644
--- a/src/pkg/runtime/runtime.c
+++ b/src/pkg/runtime/runtime.c
@@ -343,7 +343,7 @@ runtime·check(void)
 	if(!(i != i1))
 		runtime·throw("float32nan3");
 
-	runtime·initsig(0);
+	runtime·initsig();
 }
 
 void
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index b29487eb1f..8ac6c7eddb 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -267,11 +267,10 @@ struct	SigTab
 };
 enum
 {
-	SigCatch = 1<<0,
-	SigIgnore = 1<<1,
-	SigRestart = 1<<2,
-	SigQueue = 1<<3,
-	SigPanic = 1<<4,
+	SigNotify = 1<<0,	// let signal.Notify have signal, even if from kernel
+	SigKill = 1<<1,  // if signal.Notify doesn't take it, exit quietly
+	SigThrow = 1<<2,  // if signal.Notify doesn't take it, exit loudly
+	SigPanic = 1<<3,  // if the signal is from the kernel, panic
 };
 
 // NOTE(rsc): keep in sync with extern.go:/type.Func.
@@ -501,7 +500,7 @@ String  runtime·gostringn(byte*, int32);
 Slice	runtime·gobytes(byte*, int32);
 String	runtime·gostringnocopy(byte*);
 String	runtime·gostringw(uint16*);
-void	runtime·initsig(int32);
+void	runtime·initsig(void);
 int32	runtime·gotraceback(void);
 void	runtime·goroutineheader(G*);
 void	runtime·traceback(uint8 *pc, uint8 *sp, uint8 *lr, G* gp);
diff --git a/src/pkg/runtime/sig.go b/src/pkg/runtime/sig.go
deleted file mode 100644
index 6d560b9007..0000000000
--- a/src/pkg/runtime/sig.go
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package runtime
-
-// Sigrecv returns a bitmask of signals that have arrived since the last call to Sigrecv.
-// It blocks until at least one signal arrives.
-func Sigrecv() uint32
-
-// Signame returns a string describing the signal, or "" if the signal is unknown.
-func Signame(sig int32) string
-
-// Siginit enables receipt of signals via Sigrecv.  It should typically
-// be called during initialization.
-func Siginit()
diff --git a/src/pkg/runtime/signal_darwin_386.c b/src/pkg/runtime/signal_darwin_386.c
index 14f99115b4..803bd242f3 100644
--- a/src/pkg/runtime/signal_darwin_386.c
+++ b/src/pkg/runtime/signal_darwin_386.c
@@ -25,14 +25,6 @@ runtime·dumpregs(Regs32 *r)
 	runtime·printf("gs      %x\n", r->gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
@@ -41,6 +33,7 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	Regs32 *r;
 	uintptr *sp;
 	byte *pc;
+	SigTab *t;
 
 	uc = context;
 	mc = uc->uc_mcontext;
@@ -51,7 +44,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Work around Leopard bug that doesn't set FPE_INTDIV.
 		// Look at instruction to see if it is a divide.
 		// Not necessary in Snow Leopard (si_code will be != 0).
@@ -87,12 +83,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -116,11 +115,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 }
 
 void
-runtime·sigignore(int32, Siginfo*, void*)
-{
-}
-
-void
 runtime·signalstack(byte *p, int32 n)
 {
 	StackT st;
@@ -131,8 +125,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -145,50 +139,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	*(uintptr*)sa.__sigaction_u = (uintptr)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_darwin_amd64.c b/src/pkg/runtime/signal_darwin_amd64.c
index c7621ddcaf..0c954294a5 100644
--- a/src/pkg/runtime/signal_darwin_amd64.c
+++ b/src/pkg/runtime/signal_darwin_amd64.c
@@ -33,14 +33,6 @@ runtime·dumpregs(Regs64 *r)
 	runtime·printf("gs      %X\n", r->gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
@@ -49,6 +41,7 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	Regs64 *r;
 	uintptr *sp;
 	byte *pc;
+	SigTab *t;
 
 	uc = context;
 	mc = uc->uc_mcontext;
@@ -59,7 +52,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Work around Leopard bug that doesn't set FPE_INTDIV.
 		// Look at instruction to see if it is a divide.
 		// Not necessary in Snow Leopard (si_code will be != 0).
@@ -96,13 +92,16 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		r->rip = (uintptr)runtime·sigpanic;
 		return;
 	}
-
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -126,11 +125,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 }
 
 void
-runtime·sigignore(int32, Siginfo*, void*)
-{
-}
-
-void
 runtime·signalstack(byte *p, int32 n)
 {
 	StackT st;
@@ -141,8 +135,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -155,50 +149,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	*(uintptr*)sa.__sigaction_u = (uintptr)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_freebsd_386.c b/src/pkg/runtime/signal_freebsd_386.c
index ff4aaabdb5..c6eb344361 100644
--- a/src/pkg/runtime/signal_freebsd_386.c
+++ b/src/pkg/runtime/signal_freebsd_386.c
@@ -50,6 +50,7 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	Ucontext *uc;
 	Mcontext *r;
 	uintptr *sp;
+	SigTab *t;
 
 	uc = context;
 	r = &uc->uc_mcontext;
@@ -59,7 +60,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -84,12 +88,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -111,13 +118,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -129,8 +129,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -144,50 +144,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_freebsd_amd64.c b/src/pkg/runtime/signal_freebsd_amd64.c
index 2683f4fd09..d307d726de 100644
--- a/src/pkg/runtime/signal_freebsd_amd64.c
+++ b/src/pkg/runtime/signal_freebsd_amd64.c
@@ -44,14 +44,6 @@ runtime·dumpregs(Mcontext *r)
 	runtime·printf("gs      %X\n", r->mc_gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
@@ -67,7 +59,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -92,12 +87,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -119,13 +117,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -137,8 +128,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -152,50 +143,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_linux_386.c b/src/pkg/runtime/signal_linux_386.c
index 4f3abcebb3..b43dbc1121 100644
--- a/src/pkg/runtime/signal_linux_386.c
+++ b/src/pkg/runtime/signal_linux_386.c
@@ -30,23 +30,15 @@ runtime·dumpregs(Sigcontext *r)
  * and calls sighandler().
  */
 extern void runtime·sigtramp(void);
-extern void runtime·sigignore(void);	// just returns
 extern void runtime·sigreturn(void);	// calls runtime·sigreturn
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
 	Ucontext *uc;
 	Sigcontext *r;
 	uintptr *sp;
+	SigTab *t;
 
 	uc = context;
 	r = &uc->uc_mcontext;
@@ -56,7 +48,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -81,12 +76,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -119,8 +117,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -136,59 +134,13 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	runtime·rt_sigaction(i, &sa, nil, 8);
 }
 
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
-
 #define AT_NULL		0
 #define AT_SYSINFO	32
 extern uint32 runtime·_vdso;
 
 #pragma textflag 7
-void runtime·linux_setup_vdso(int32 argc, void *argv_list)
+void
+runtime·linux_setup_vdso(int32 argc, void *argv_list)
 {
 	byte **argv = &argv_list;
 	byte **envp;
@@ -204,5 +156,5 @@ void runtime·linux_setup_vdso(int32 argc, void *argv_list)
 			runtime·_vdso = auxv[1];
 			break;
 		}
-	}		
+	}
 }
diff --git a/src/pkg/runtime/signal_linux_amd64.c b/src/pkg/runtime/signal_linux_amd64.c
index 937d5c3478..551744b78d 100644
--- a/src/pkg/runtime/signal_linux_amd64.c
+++ b/src/pkg/runtime/signal_linux_amd64.c
@@ -38,17 +38,8 @@ runtime·dumpregs(Sigcontext *r)
  * and calls sighandler().
  */
 extern void runtime·sigtramp(void);
-extern void runtime·sigignore(void);	// just returns
 extern void runtime·sigreturn(void);	// calls runtime·sigreturn
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
@@ -56,6 +47,7 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	Mcontext *mc;
 	Sigcontext *r;
 	uintptr *sp;
+	SigTab *t;
 
 	uc = context;
 	mc = &uc->uc_mcontext;
@@ -66,7 +58,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -91,12 +86,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -129,8 +127,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -145,50 +143,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.sa_handler = fn;
 	runtime·rt_sigaction(i, &sa, nil, 8);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_linux_arm.c b/src/pkg/runtime/signal_linux_arm.c
index b32ec7a226..a0905d3c52 100644
--- a/src/pkg/runtime/signal_linux_arm.c
+++ b/src/pkg/runtime/signal_linux_arm.c
@@ -38,17 +38,8 @@ runtime·dumpregs(Sigcontext *r)
  * and calls sighandler().
  */
 extern void runtime·sigtramp(void);
-extern void runtime·sigignore(void);	// just returns
 extern void runtime·sigreturn(void);	// calls runtime·sigreturn
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
@@ -124,8 +115,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -140,50 +131,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.sa_handler = fn;
 	runtime·rt_sigaction(i, &sa, nil, 8);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_netbsd_386.c b/src/pkg/runtime/signal_netbsd_386.c
index 74fa1d490b..739b359ee6 100644
--- a/src/pkg/runtime/signal_netbsd_386.c
+++ b/src/pkg/runtime/signal_netbsd_386.c
@@ -36,26 +36,22 @@ runtime·dumpregs(Sigcontext *r)
 	runtime·printf("gs      %x\n", r->sc_gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
 	Sigcontext *r = context;
 	uintptr *sp;
+	SigTab *t;
 
 	if(sig == SIGPROF) {
 		runtime·sigprof((uint8*)r->sc_eip, (uint8*)r->sc_esp, nil, gp);
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -80,12 +76,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -107,13 +106,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -125,8 +117,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -140,50 +132,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_netbsd_amd64.c b/src/pkg/runtime/signal_netbsd_amd64.c
index 6c69fa7339..e71f23551d 100644
--- a/src/pkg/runtime/signal_netbsd_amd64.c
+++ b/src/pkg/runtime/signal_netbsd_amd64.c
@@ -44,19 +44,12 @@ runtime·dumpregs(Sigcontext *r)
 	runtime·printf("gs      %X\n", r->sc_gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
 	Sigcontext *r = context;
 	uintptr *sp;
+	SigTab *t;
 
 	if(sig == SIGPROF) {
 		runtime·sigprof((uint8*)r->sc_rip,
@@ -64,7 +57,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -89,13 +85,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig)
-		|| (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -117,13 +115,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -135,8 +126,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -150,50 +141,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_openbsd_386.c b/src/pkg/runtime/signal_openbsd_386.c
index 74fa1d490b..739b359ee6 100644
--- a/src/pkg/runtime/signal_openbsd_386.c
+++ b/src/pkg/runtime/signal_openbsd_386.c
@@ -36,26 +36,22 @@ runtime·dumpregs(Sigcontext *r)
 	runtime·printf("gs      %x\n", r->sc_gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
 	Sigcontext *r = context;
 	uintptr *sp;
+	SigTab *t;
 
 	if(sig == SIGPROF) {
 		runtime·sigprof((uint8*)r->sc_eip, (uint8*)r->sc_esp, nil, gp);
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -80,12 +76,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -107,13 +106,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -125,8 +117,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -140,50 +132,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_openbsd_amd64.c b/src/pkg/runtime/signal_openbsd_amd64.c
index 6c69fa7339..e71f23551d 100644
--- a/src/pkg/runtime/signal_openbsd_amd64.c
+++ b/src/pkg/runtime/signal_openbsd_amd64.c
@@ -44,19 +44,12 @@ runtime·dumpregs(Sigcontext *r)
 	runtime·printf("gs      %X\n", r->sc_gs);
 }
 
-String
-runtime·signame(int32 sig)
-{
-	if(sig < 0 || sig >= NSIG)
-		return runtime·emptystring;
-	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
-}
-
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 {
 	Sigcontext *r = context;
 	uintptr *sp;
+	SigTab *t;
 
 	if(sig == SIGPROF) {
 		runtime·sigprof((uint8*)r->sc_rip,
@@ -64,7 +57,10 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+	t = &runtime·sigtab[sig];
+	if(info->si_code != SI_USER && (t->flags & SigPanic)) {
+		if(gp == nil)
+			goto Throw;
 		// Make it look like a call to the signal func.
 		// Have to pass arguments out of band since
 		// augmenting the stack frame would break
@@ -89,13 +85,15 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 		return;
 	}
 
-	if(runtime·sigtab[sig].flags & SigQueue) {
-		if(runtime·sigsend(sig)
-		|| (runtime·sigtab[sig].flags & SigIgnore))
+	if(info->si_code == SI_USER || (t->flags & SigNotify))
+		if(runtime·sigsend(sig))
 			return;
-		runtime·exit(2);	// SIGINT, SIGTERM, etc
-	}
+	if(t->flags & SigKill)
+		runtime·exit(2);
+	if(!(t->flags & SigThrow))
+		return;
 
+Throw:
 	if(runtime·panicking)	// traceback already printed
 		runtime·exit(2);
 	runtime·panicking = 1;
@@ -117,13 +115,6 @@ runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
 	runtime·exit(2);
 }
 
-// Called from kernel on signal stack, so no stack split.
-#pragma textflag 7
-void
-runtime·sigignore(void)
-{
-}
-
 void
 runtime·signalstack(byte *p, int32 n)
 {
@@ -135,8 +126,8 @@ runtime·signalstack(byte *p, int32 n)
 	runtime·sigaltstack(&st, nil);
 }
 
-static void
-sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+void
+runtime·setsig(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 {
 	Sigaction sa;
 
@@ -150,50 +141,3 @@ sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
 	sa.__sigaction_u.__sa_sigaction = (void*)fn;
 	runtime·sigaction(i, &sa, nil);
 }
-
-void
-runtime·initsig(int32 queue)
-{
-	int32 i;
-	void *fn;
-
-	runtime·siginit();
-
-	for(i = 0; i<NSIG; i++) {
-		if(runtime·sigtab[i].flags) {
-			if((runtime·sigtab[i].flags & SigQueue) != queue)
-				continue;
-			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
-				fn = runtime·sighandler;
-			else
-				fn = runtime·sigignore;
-			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
-		}
-	}
-}
-
-void
-runtime·resetcpuprofiler(int32 hz)
-{
-	Itimerval it;
-	
-	runtime·memclr((byte*)&it, sizeof it);
-	if(hz == 0) {
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-		sigaction(SIGPROF, SIG_IGN, true);
-	} else {
-		sigaction(SIGPROF, runtime·sighandler, true);
-		it.it_interval.tv_sec = 0;
-		it.it_interval.tv_usec = 1000000 / hz;
-		it.it_value = it.it_interval;
-		runtime·setitimer(ITIMER_PROF, &it, nil);
-	}
-	m->profilehz = hz;
-}
-
-void
-os·sigpipe(void)
-{
-	sigaction(SIGPIPE, SIG_DFL, false);
-	runtime·raisesigpipe();
-}
diff --git a/src/pkg/runtime/signal_unix.c b/src/pkg/runtime/signal_unix.c
new file mode 100644
index 0000000000..14ce1418f8
--- /dev/null
+++ b/src/pkg/runtime/signal_unix.c
@@ -0,0 +1,60 @@
+// Copyright 2012 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin freebsd linux openbsd netbsd
+
+#include "runtime.h"
+#include "defs_GOOS_GOARCH.h"
+#include "os_GOOS.h"
+
+extern SigTab runtime·sigtab[];
+
+String
+runtime·signame(int32 sig)
+{
+	if(sig < 0 || sig >= NSIG)
+		return runtime·emptystring;
+	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
+}
+
+void
+runtime·initsig(void)
+{
+	int32 i;
+	SigTab *t;
+
+	// First call: basic setup.
+	for(i = 0; i<NSIG; i++) {
+		t = &runtime·sigtab[i];
+		if(t->flags == 0)
+			continue;
+		runtime·setsig(i, runtime·sighandler, 1);
+	}
+}
+
+void
+runtime·resetcpuprofiler(int32 hz)
+{
+	Itimerval it;
+	
+	runtime·memclr((byte*)&it, sizeof it);
+	if(hz == 0) {
+		runtime·setitimer(ITIMER_PROF, &it, nil);
+		runtime·setsig(SIGPROF, SIG_IGN, true);
+	} else {
+		runtime·setsig(SIGPROF, runtime·sighandler, true);
+		it.it_interval.tv_sec = 0;
+		it.it_interval.tv_usec = 1000000 / hz;
+		it.it_value = it.it_interval;
+		runtime·setitimer(ITIMER_PROF, &it, nil);
+	}
+	m->profilehz = hz;
+}
+
+void
+os·sigpipe(void)
+{
+	runtime·setsig(SIGPIPE, SIG_DFL, false);
+	runtime·raisesigpipe();
+}
diff --git a/src/pkg/runtime/signal_windows_386.c b/src/pkg/runtime/signal_windows_386.c
index 48d2a8bff9..c99f2a176e 100644
--- a/src/pkg/runtime/signal_windows_386.c
+++ b/src/pkg/runtime/signal_windows_386.c
@@ -25,7 +25,7 @@ runtime·dumpregs(Context *r)
 }
 
 void
-runtime·initsig(int32)
+runtime·initsig(void)
 {
 	runtime·siginit();
 }
diff --git a/src/pkg/runtime/signal_windows_amd64.c b/src/pkg/runtime/signal_windows_amd64.c
index 92cdb8054f..58d70a4089 100644
--- a/src/pkg/runtime/signal_windows_amd64.c
+++ b/src/pkg/runtime/signal_windows_amd64.c
@@ -35,7 +35,7 @@ runtime·dumpregs(Context *r)
 }
 
 void
-runtime·initsig(int32)
+runtime·initsig(void)
 {
 	runtime·siginit();
 	// following line keeps sigtramp alive at link stage
diff --git a/src/pkg/runtime/signals_darwin.h b/src/pkg/runtime/signals_darwin.h
index 035027fadd..4ff08bcdc9 100644
--- a/src/pkg/runtime/signals_darwin.h
+++ b/src/pkg/runtime/signals_darwin.h
@@ -2,50 +2,47 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-#define C SigCatch
-#define I SigIgnore
-#define R SigRestart
-#define Q SigQueue
+#define N SigNotify
+#define K SigKill
+#define T SigThrow
 #define P SigPanic
 
 SigTab runtime·sigtab[] = {
 	/* 0 */	0, "SIGNONE: no trap",
-	/* 1 */	Q+R, "SIGHUP: terminal line hangup",
-	/* 2 */	Q+R, "SIGINT: interrupt",
-	/* 3 */	C, "SIGQUIT: quit",
-	/* 4 */	C, "SIGILL: illegal instruction",
-	/* 5 */	C, "SIGTRAP: trace trap",	/* used by panic and array out of bounds, etc. */
-	/* 6 */	C, "SIGABRT: abort",
-	/* 7 */	C, "SIGEMT: emulate instruction executed",
-	/* 8 */	C+P, "SIGFPE: floating-point exception",
+	/* 1 */	N+K, "SIGHUP: terminal line hangup",
+	/* 2 */	N+K, "SIGINT: interrupt",
+	/* 3 */	N+T, "SIGQUIT: quit",
+	/* 4 */	T, "SIGILL: illegal instruction",
+	/* 5 */	T, "SIGTRAP: trace trap",
+	/* 6 */	N+T, "SIGABRT: abort",
+	/* 7 */	T, "SIGEMT: emulate instruction executed",
+	/* 8 */	P, "SIGFPE: floating-point exception",
 	/* 9 */	0, "SIGKILL: kill",
-	/* 10 */	C+P, "SIGBUS: bus error",
-	/* 11 */	C+P, "SIGSEGV: segmentation violation",
-	/* 12 */	C, "SIGSYS: bad system call",
-	/* 13 */	I, "SIGPIPE: write to broken pipe",
-	/* 14 */	Q+I+R, "SIGALRM: alarm clock",
-	/* 15 */	Q+R, "SIGTERM: termination",
-	/* 16 */	Q+I+R, "SIGURG: urgent condition on socket",
+	/* 10 */	P, "SIGBUS: bus error",
+	/* 11 */	P, "SIGSEGV: segmentation violation",
+	/* 12 */	T, "SIGSYS: bad system call",
+	/* 13 */	N, "SIGPIPE: write to broken pipe",
+	/* 14 */	N, "SIGALRM: alarm clock",
+	/* 15 */	N+K, "SIGTERM: termination",
+	/* 16 */	N, "SIGURG: urgent condition on socket",
 	/* 17 */	0, "SIGSTOP: stop",
-	/* 18 */	Q+I+R, "SIGTSTP: keyboard stop",
+	/* 18 */	N, "SIGTSTP: keyboard stop",
 	/* 19 */	0, "SIGCONT: continue after stop",
-	/* 20 */	Q+I+R, "SIGCHLD: child status has changed",
-	/* 21 */	Q+I+R, "SIGTTIN: background read from tty",
-	/* 22 */	Q+I+R, "SIGTTOU: background write to tty",
-	/* 23 */	Q+I+R, "SIGIO: i/o now possible",
-	/* 24 */	Q+I+R, "SIGXCPU: cpu limit exceeded",
-	/* 25 */	Q+I+R, "SIGXFSZ: file size limit exceeded",
-	/* 26 */	Q+I+R, "SIGVTALRM: virtual alarm clock",
-	/* 27 */	Q+I+R, "SIGPROF: profiling alarm clock",
-	/* 28 */	Q+I+R, "SIGWINCH: window size change",
-	/* 29 */	Q+I+R, "SIGINFO: status request from keyboard",
-	/* 30 */	Q+I+R, "SIGUSR1: user-defined signal 1",
-	/* 31 */	Q+I+R, "SIGUSR2: user-defined signal 2",
+	/* 20 */	N, "SIGCHLD: child status has changed",
+	/* 21 */	N, "SIGTTIN: background read from tty",
+	/* 22 */	N, "SIGTTOU: background write to tty",
+	/* 23 */	N, "SIGIO: i/o now possible",
+	/* 24 */	N, "SIGXCPU: cpu limit exceeded",
+	/* 25 */	N, "SIGXFSZ: file size limit exceeded",
+	/* 26 */	N, "SIGVTALRM: virtual alarm clock",
+	/* 27 */	N, "SIGPROF: profiling alarm clock",
+	/* 28 */	N, "SIGWINCH: window size change",
+	/* 29 */	N, "SIGINFO: status request from keyboard",
+	/* 30 */	N, "SIGUSR1: user-defined signal 1",
+	/* 31 */	N, "SIGUSR2: user-defined signal 2",
 };
-#undef C
-#undef I
-#undef R
-#undef Q
-#undef P
 
-#define	NSIG 32
+#undef N
+#undef K
+#undef T
+#undef P
diff --git a/src/pkg/runtime/signals_freebsd.h b/src/pkg/runtime/signals_freebsd.h
index 63a84671d9..6a15017325 100644
--- a/src/pkg/runtime/signals_freebsd.h
+++ b/src/pkg/runtime/signals_freebsd.h
@@ -2,51 +2,48 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-#define C SigCatch
-#define I SigIgnore
-#define R SigRestart
-#define Q SigQueue
+#define N SigNotify
+#define K SigKill
+#define T SigThrow
 #define P SigPanic
 
 SigTab runtime·sigtab[] = {
-	/* 0 */		0, "SIGNONE: no trap",
-	/* 1 */		Q+R, "SIGHUP: terminal line hangup",
-	/* 2 */		Q+R, "SIGINT: interrupt",
-	/* 3 */		C, "SIGQUIT: quit",
-	/* 4 */		C, "SIGILL: illegal instruction",
-	/* 5 */		C, "SIGTRAP: trace trap",
-	/* 6 */		C, "SIGABRT: abort",
-	/* 7 */		C, "SIGEMT: EMT instruction",
-	/* 8 */		C+P, "SIGFPE: floating-point exception",
-	/* 9 */		0, "SIGKILL: kill",
-	/* 10 */	C+P, "SIGBUS: bus error",
-	/* 11 */	C+P, "SIGSEGV: segmentation violation",
-	/* 12 */	C, "SIGSYS: bad system call",
-	/* 13 */	I, "SIGPIPE: write to broken pipe",
-	/* 14 */	Q+I+R, "SIGALRM: alarm clock",
-	/* 15 */	Q+R, "SIGTERM: termination",
-	/* 16 */	Q+I+R, "SIGURG: urgent condition on socket",
-	/* 17 */	0, "SIGSTOP: stop, unblockable",
-	/* 18 */	Q+I+R, "SIGTSTP: stop from tty",
-	/* 19 */	0, "SIGCONT: continue",
-	/* 20 */	Q+I+R, "SIGCHLD: child status has changed",
-	/* 21 */	Q+I+R, "SIGTTIN: background read from tty",
-	/* 22 */	Q+I+R, "SIGTTOU: background write to tty",
-	/* 23 */	Q+I+R, "SIGIO: i/o now possible",
-	/* 24 */	Q+I+R, "SIGXCPU: cpu limit exceeded",
-	/* 25 */	Q+I+R, "SIGXFSZ: file size limit exceeded",
-	/* 26 */	Q+I+R, "SIGVTALRM: virtual alarm clock",
-	/* 27 */	Q+I+R, "SIGPROF: profiling alarm clock",
-	/* 28 */	Q+I+R, "SIGWINCH: window size change",
-	/* 29 */	Q+I+R, "SIGINFO: information request",
-	/* 30 */	Q+I+R, "SIGUSR1: user-defined signal 1",
-	/* 31 */	Q+I+R, "SIGUSR2: user-defined signal 2",
-	/* 32 */	Q+I+R, "SIGTHR: reserved",
+	/* 0 */	0, "SIGNONE: no trap",
+	/* 1 */	N+K, "SIGHUP: terminal line hangup",
+	/* 2 */	N+K, "SIGINT: interrupt",
+	/* 3 */	N+T, "SIGQUIT: quit",
+	/* 4 */	T, "SIGILL: illegal instruction",
+	/* 5 */	T, "SIGTRAP: trace trap",
+	/* 6 */	N+T, "SIGABRT: abort",
+	/* 7 */	T, "SIGEMT: emulate instruction executed",
+	/* 8 */	P, "SIGFPE: floating-point exception",
+	/* 9 */	0, "SIGKILL: kill",
+	/* 10 */	P, "SIGBUS: bus error",
+	/* 11 */	P, "SIGSEGV: segmentation violation",
+	/* 12 */	T, "SIGSYS: bad system call",
+	/* 13 */	N, "SIGPIPE: write to broken pipe",
+	/* 14 */	N, "SIGALRM: alarm clock",
+	/* 15 */	N+K, "SIGTERM: termination",
+	/* 16 */	N, "SIGURG: urgent condition on socket",
+	/* 17 */	0, "SIGSTOP: stop",
+	/* 18 */	N, "SIGTSTP: keyboard stop",
+	/* 19 */	0, "SIGCONT: continue after stop",
+	/* 20 */	N, "SIGCHLD: child status has changed",
+	/* 21 */	N, "SIGTTIN: background read from tty",
+	/* 22 */	N, "SIGTTOU: background write to tty",
+	/* 23 */	N, "SIGIO: i/o now possible",
+	/* 24 */	N, "SIGXCPU: cpu limit exceeded",
+	/* 25 */	N, "SIGXFSZ: file size limit exceeded",
+	/* 26 */	N, "SIGVTALRM: virtual alarm clock",
+	/* 27 */	N, "SIGPROF: profiling alarm clock",
+	/* 28 */	N, "SIGWINCH: window size change",
+	/* 29 */	N, "SIGINFO: status request from keyboard",
+	/* 30 */	N, "SIGUSR1: user-defined signal 1",
+	/* 31 */	N, "SIGUSR2: user-defined signal 2",
+	/* 32 */	N, "SIGTHR: reserved",
 };
-#undef C
-#undef I
-#undef R
-#undef Q
-#undef P
 
-#define	NSIG 33
+#undef N
+#undef K
+#undef T
+#undef P
diff --git a/src/pkg/runtime/signals_linux.h b/src/pkg/runtime/signals_linux.h
index 1fc5f8c87c..1df063a187 100644
--- a/src/pkg/runtime/signals_linux.h
+++ b/src/pkg/runtime/signals_linux.h
@@ -2,50 +2,80 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-#define C SigCatch
-#define I SigIgnore
-#define R SigRestart
-#define Q SigQueue
+#define N SigNotify
+#define K SigKill
+#define T SigThrow
 #define P SigPanic
 
 SigTab runtime·sigtab[] = {
 	/* 0 */	0, "SIGNONE: no trap",
-	/* 1 */	Q+R, "SIGHUP: terminal line hangup",
-	/* 2 */	Q+R, "SIGINT: interrupt",
-	/* 3 */	C, "SIGQUIT: quit",
-	/* 4 */	C, "SIGILL: illegal instruction",
-	/* 5 */	C, "SIGTRAP: trace trap",
-	/* 6 */	C, "SIGABRT: abort",
-	/* 7 */	C+P, "SIGBUS: bus error",
-	/* 8 */	C+P, "SIGFPE: floating-point exception",
+	/* 1 */	N+K, "SIGHUP: terminal line hangup",
+	/* 2 */	N+K, "SIGINT: interrupt",
+	/* 3 */	N+T, "SIGQUIT: quit",
+	/* 4 */	T, "SIGILL: illegal instruction",
+	/* 5 */	T, "SIGTRAP: trace trap",
+	/* 6 */	N+T, "SIGABRT: abort",
+	/* 7 */	P, "SIGBUS: bus error",
+	/* 8 */	P, "SIGFPE: floating-point exception",
 	/* 9 */	0, "SIGKILL: kill",
-	/* 10 */	Q+I+R, "SIGUSR1: user-defined signal 1",
-	/* 11 */	C+P, "SIGSEGV: segmentation violation",
-	/* 12 */	Q+I+R, "SIGUSR2: user-defined signal 2",
-	/* 13 */	I, "SIGPIPE: write to broken pipe",
-	/* 14 */	Q+I+R, "SIGALRM: alarm clock",
-	/* 15 */	Q+R, "SIGTERM: termination",
-	/* 16 */	C, "SIGSTKFLT: stack fault",
-	/* 17 */	Q+I+R, "SIGCHLD: child status has changed",
+	/* 10 */	N, "SIGUSR1: user-defined signal 1",
+	/* 11 */	P, "SIGSEGV: segmentation violation",
+	/* 12 */	N, "SIGUSR2: user-defined signal 2",
+	/* 13 */	N, "SIGPIPE: write to broken pipe",
+	/* 14 */	N, "SIGALRM: alarm clock",
+	/* 15 */	N+K, "SIGTERM: termination",
+	/* 16 */	T, "SIGSTKFLT: stack fault",
+	/* 17 */	N, "SIGCHLD: child status has changed",
 	/* 18 */	0, "SIGCONT: continue",
 	/* 19 */	0, "SIGSTOP: stop, unblockable",
-	/* 20 */	Q+I+R, "SIGTSTP: keyboard stop",
-	/* 21 */	Q+I+R, "SIGTTIN: background read from tty",
-	/* 22 */	Q+I+R, "SIGTTOU: background write to tty",
-	/* 23 */	Q+I+R, "SIGURG: urgent condition on socket",
-	/* 24 */	Q+I+R, "SIGXCPU: cpu limit exceeded",
-	/* 25 */	Q+I+R, "SIGXFSZ: file size limit exceeded",
-	/* 26 */	Q+I+R, "SIGVTALRM: virtual alarm clock",
-	/* 27 */	Q+I+R, "SIGPROF: profiling alarm clock",
-	/* 28 */	Q+I+R, "SIGWINCH: window size change",
-	/* 29 */	Q+I+R, "SIGIO: i/o now possible",
-	/* 30 */	Q+I+R, "SIGPWR: power failure restart",
-	/* 31 */	C, "SIGSYS: bad system call",
+	/* 20 */	N, "SIGTSTP: keyboard stop",
+	/* 21 */	N, "SIGTTIN: background read from tty",
+	/* 22 */	N, "SIGTTOU: background write to tty",
+	/* 23 */	N, "SIGURG: urgent condition on socket",
+	/* 24 */	N, "SIGXCPU: cpu limit exceeded",
+	/* 25 */	N, "SIGXFSZ: file size limit exceeded",
+	/* 26 */	N, "SIGVTALRM: virtual alarm clock",
+	/* 27 */	N, "SIGPROF: profiling alarm clock",
+	/* 28 */	N, "SIGWINCH: window size change",
+	/* 29 */	N, "SIGIO: i/o now possible",
+	/* 30 */	N, "SIGPWR: power failure restart",
+	/* 31 */	N, "SIGSYS: bad system call",
+	/* 32 */	N, "signal 32",
+	/* 33 */	N, "signal 33",
+	/* 34 */	N, "signal 34",
+	/* 35 */	N, "signal 35",
+	/* 36 */	N, "signal 36",
+	/* 37 */	N, "signal 37",
+	/* 38 */	N, "signal 38",
+	/* 39 */	N, "signal 39",
+	/* 40 */	N, "signal 40",
+	/* 41 */	N, "signal 41",
+	/* 42 */	N, "signal 42",
+	/* 43 */	N, "signal 43",
+	/* 44 */	N, "signal 44",
+	/* 45 */	N, "signal 45",
+	/* 46 */	N, "signal 46",
+	/* 47 */	N, "signal 47",
+	/* 48 */	N, "signal 48",
+	/* 49 */	N, "signal 49",
+	/* 50 */	N, "signal 50",
+	/* 51 */	N, "signal 51",
+	/* 52 */	N, "signal 52",
+	/* 53 */	N, "signal 53",
+	/* 54 */	N, "signal 54",
+	/* 55 */	N, "signal 55",
+	/* 56 */	N, "signal 56",
+	/* 57 */	N, "signal 57",
+	/* 58 */	N, "signal 58",
+	/* 59 */	N, "signal 59",
+	/* 60 */	N, "signal 60",
+	/* 61 */	N, "signal 61",
+	/* 62 */	N, "signal 62",
+	/* 63 */	N, "signal 63",
+	/* 64 */	N, "signal 64",
 };
-#undef C
-#undef I
-#undef R
-#undef Q
-#undef P
 
-#define	NSIG 32
+#undef N
+#undef K
+#undef T
+#undef P
diff --git a/src/pkg/runtime/signals_netbsd.h b/src/pkg/runtime/signals_netbsd.h
index 63a84671d9..6a15017325 100644
--- a/src/pkg/runtime/signals_netbsd.h
+++ b/src/pkg/runtime/signals_netbsd.h
@@ -2,51 +2,48 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-#define C SigCatch
-#define I SigIgnore
-#define R SigRestart
-#define Q SigQueue
+#define N SigNotify
+#define K SigKill
+#define T SigThrow
 #define P SigPanic
 
 SigTab runtime·sigtab[] = {
-	/* 0 */		0, "SIGNONE: no trap",
-	/* 1 */		Q+R, "SIGHUP: terminal line hangup",
-	/* 2 */		Q+R, "SIGINT: interrupt",
-	/* 3 */		C, "SIGQUIT: quit",
-	/* 4 */		C, "SIGILL: illegal instruction",
-	/* 5 */		C, "SIGTRAP: trace trap",
-	/* 6 */		C, "SIGABRT: abort",
-	/* 7 */		C, "SIGEMT: EMT instruction",
-	/* 8 */		C+P, "SIGFPE: floating-point exception",
-	/* 9 */		0, "SIGKILL: kill",
-	/* 10 */	C+P, "SIGBUS: bus error",
-	/* 11 */	C+P, "SIGSEGV: segmentation violation",
-	/* 12 */	C, "SIGSYS: bad system call",
-	/* 13 */	I, "SIGPIPE: write to broken pipe",
-	/* 14 */	Q+I+R, "SIGALRM: alarm clock",
-	/* 15 */	Q+R, "SIGTERM: termination",
-	/* 16 */	Q+I+R, "SIGURG: urgent condition on socket",
-	/* 17 */	0, "SIGSTOP: stop, unblockable",
-	/* 18 */	Q+I+R, "SIGTSTP: stop from tty",
-	/* 19 */	0, "SIGCONT: continue",
-	/* 20 */	Q+I+R, "SIGCHLD: child status has changed",
-	/* 21 */	Q+I+R, "SIGTTIN: background read from tty",
-	/* 22 */	Q+I+R, "SIGTTOU: background write to tty",
-	/* 23 */	Q+I+R, "SIGIO: i/o now possible",
-	/* 24 */	Q+I+R, "SIGXCPU: cpu limit exceeded",
-	/* 25 */	Q+I+R, "SIGXFSZ: file size limit exceeded",
-	/* 26 */	Q+I+R, "SIGVTALRM: virtual alarm clock",
-	/* 27 */	Q+I+R, "SIGPROF: profiling alarm clock",
-	/* 28 */	Q+I+R, "SIGWINCH: window size change",
-	/* 29 */	Q+I+R, "SIGINFO: information request",
-	/* 30 */	Q+I+R, "SIGUSR1: user-defined signal 1",
-	/* 31 */	Q+I+R, "SIGUSR2: user-defined signal 2",
-	/* 32 */	Q+I+R, "SIGTHR: reserved",
+	/* 0 */	0, "SIGNONE: no trap",
+	/* 1 */	N+K, "SIGHUP: terminal line hangup",
+	/* 2 */	N+K, "SIGINT: interrupt",
+	/* 3 */	N+T, "SIGQUIT: quit",
+	/* 4 */	T, "SIGILL: illegal instruction",
+	/* 5 */	T, "SIGTRAP: trace trap",
+	/* 6 */	N+T, "SIGABRT: abort",
+	/* 7 */	T, "SIGEMT: emulate instruction executed",
+	/* 8 */	P, "SIGFPE: floating-point exception",
+	/* 9 */	0, "SIGKILL: kill",
+	/* 10 */	P, "SIGBUS: bus error",
+	/* 11 */	P, "SIGSEGV: segmentation violation",
+	/* 12 */	T, "SIGSYS: bad system call",
+	/* 13 */	N, "SIGPIPE: write to broken pipe",
+	/* 14 */	N, "SIGALRM: alarm clock",
+	/* 15 */	N+K, "SIGTERM: termination",
+	/* 16 */	N, "SIGURG: urgent condition on socket",
+	/* 17 */	0, "SIGSTOP: stop",
+	/* 18 */	N, "SIGTSTP: keyboard stop",
+	/* 19 */	0, "SIGCONT: continue after stop",
+	/* 20 */	N, "SIGCHLD: child status has changed",
+	/* 21 */	N, "SIGTTIN: background read from tty",
+	/* 22 */	N, "SIGTTOU: background write to tty",
+	/* 23 */	N, "SIGIO: i/o now possible",
+	/* 24 */	N, "SIGXCPU: cpu limit exceeded",
+	/* 25 */	N, "SIGXFSZ: file size limit exceeded",
+	/* 26 */	N, "SIGVTALRM: virtual alarm clock",
+	/* 27 */	N, "SIGPROF: profiling alarm clock",
+	/* 28 */	N, "SIGWINCH: window size change",
+	/* 29 */	N, "SIGINFO: status request from keyboard",
+	/* 30 */	N, "SIGUSR1: user-defined signal 1",
+	/* 31 */	N, "SIGUSR2: user-defined signal 2",
+	/* 32 */	N, "SIGTHR: reserved",
 };
-#undef C
-#undef I
-#undef R
-#undef Q
-#undef P
 
-#define	NSIG 33
+#undef N
+#undef K
+#undef T
+#undef P
diff --git a/src/pkg/runtime/signals_openbsd.h b/src/pkg/runtime/signals_openbsd.h
index 63a84671d9..6a15017325 100644
--- a/src/pkg/runtime/signals_openbsd.h
+++ b/src/pkg/runtime/signals_openbsd.h
@@ -2,51 +2,48 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-#define C SigCatch
-#define I SigIgnore
-#define R SigRestart
-#define Q SigQueue
+#define N SigNotify
+#define K SigKill
+#define T SigThrow
 #define P SigPanic
 
 SigTab runtime·sigtab[] = {
-	/* 0 */		0, "SIGNONE: no trap",
-	/* 1 */		Q+R, "SIGHUP: terminal line hangup",
-	/* 2 */		Q+R, "SIGINT: interrupt",
-	/* 3 */		C, "SIGQUIT: quit",
-	/* 4 */		C, "SIGILL: illegal instruction",
-	/* 5 */		C, "SIGTRAP: trace trap",
-	/* 6 */		C, "SIGABRT: abort",
-	/* 7 */		C, "SIGEMT: EMT instruction",
-	/* 8 */		C+P, "SIGFPE: floating-point exception",
-	/* 9 */		0, "SIGKILL: kill",
-	/* 10 */	C+P, "SIGBUS: bus error",
-	/* 11 */	C+P, "SIGSEGV: segmentation violation",
-	/* 12 */	C, "SIGSYS: bad system call",
-	/* 13 */	I, "SIGPIPE: write to broken pipe",
-	/* 14 */	Q+I+R, "SIGALRM: alarm clock",
-	/* 15 */	Q+R, "SIGTERM: termination",
-	/* 16 */	Q+I+R, "SIGURG: urgent condition on socket",
-	/* 17 */	0, "SIGSTOP: stop, unblockable",
-	/* 18 */	Q+I+R, "SIGTSTP: stop from tty",
-	/* 19 */	0, "SIGCONT: continue",
-	/* 20 */	Q+I+R, "SIGCHLD: child status has changed",
-	/* 21 */	Q+I+R, "SIGTTIN: background read from tty",
-	/* 22 */	Q+I+R, "SIGTTOU: background write to tty",
-	/* 23 */	Q+I+R, "SIGIO: i/o now possible",
-	/* 24 */	Q+I+R, "SIGXCPU: cpu limit exceeded",
-	/* 25 */	Q+I+R, "SIGXFSZ: file size limit exceeded",
-	/* 26 */	Q+I+R, "SIGVTALRM: virtual alarm clock",
-	/* 27 */	Q+I+R, "SIGPROF: profiling alarm clock",
-	/* 28 */	Q+I+R, "SIGWINCH: window size change",
-	/* 29 */	Q+I+R, "SIGINFO: information request",
-	/* 30 */	Q+I+R, "SIGUSR1: user-defined signal 1",
-	/* 31 */	Q+I+R, "SIGUSR2: user-defined signal 2",
-	/* 32 */	Q+I+R, "SIGTHR: reserved",
+	/* 0 */	0, "SIGNONE: no trap",
+	/* 1 */	N+K, "SIGHUP: terminal line hangup",
+	/* 2 */	N+K, "SIGINT: interrupt",
+	/* 3 */	N+T, "SIGQUIT: quit",
+	/* 4 */	T, "SIGILL: illegal instruction",
+	/* 5 */	T, "SIGTRAP: trace trap",
+	/* 6 */	N+T, "SIGABRT: abort",
+	/* 7 */	T, "SIGEMT: emulate instruction executed",
+	/* 8 */	P, "SIGFPE: floating-point exception",
+	/* 9 */	0, "SIGKILL: kill",
+	/* 10 */	P, "SIGBUS: bus error",
+	/* 11 */	P, "SIGSEGV: segmentation violation",
+	/* 12 */	T, "SIGSYS: bad system call",
+	/* 13 */	N, "SIGPIPE: write to broken pipe",
+	/* 14 */	N, "SIGALRM: alarm clock",
+	/* 15 */	N+K, "SIGTERM: termination",
+	/* 16 */	N, "SIGURG: urgent condition on socket",
+	/* 17 */	0, "SIGSTOP: stop",
+	/* 18 */	N, "SIGTSTP: keyboard stop",
+	/* 19 */	0, "SIGCONT: continue after stop",
+	/* 20 */	N, "SIGCHLD: child status has changed",
+	/* 21 */	N, "SIGTTIN: background read from tty",
+	/* 22 */	N, "SIGTTOU: background write to tty",
+	/* 23 */	N, "SIGIO: i/o now possible",
+	/* 24 */	N, "SIGXCPU: cpu limit exceeded",
+	/* 25 */	N, "SIGXFSZ: file size limit exceeded",
+	/* 26 */	N, "SIGVTALRM: virtual alarm clock",
+	/* 27 */	N, "SIGPROF: profiling alarm clock",
+	/* 28 */	N, "SIGWINCH: window size change",
+	/* 29 */	N, "SIGINFO: status request from keyboard",
+	/* 30 */	N, "SIGUSR1: user-defined signal 1",
+	/* 31 */	N, "SIGUSR2: user-defined signal 2",
+	/* 32 */	N, "SIGTHR: reserved",
 };
-#undef C
-#undef I
-#undef R
-#undef Q
-#undef P
 
-#define	NSIG 33
+#undef N
+#undef K
+#undef T
+#undef P
diff --git a/src/pkg/runtime/sigqueue.goc b/src/pkg/runtime/sigqueue.goc
index 3c12e5caf5..e59b704fff 100644
--- a/src/pkg/runtime/sigqueue.goc
+++ b/src/pkg/runtime/sigqueue.goc
@@ -39,36 +39,33 @@
 package runtime
 #include "runtime.h"
 #include "defs_GOOS_GOARCH.h"
+#include "os_GOOS.h"
 
 static struct {
 	Note;
-	uint32 mask;
+	uint32 mask[(NSIG+31)/32];
+	uint32 wanted[(NSIG+31)/32];
+	uint32 kick;
 	bool inuse;
 } sig;
 
-void
-runtime·siginit(void)
-{
-	runtime·noteclear(&sig);
-}
-
 // Called from sighandler to send a signal back out of the signal handling thread.
 bool
 runtime·sigsend(int32 s)
 {
 	uint32 bit, mask;
 
-	if(!sig.inuse)
+	if(!sig.inuse || s < 0 || s >= 32*nelem(sig.wanted) || !(sig.wanted[s/32]&(1U<<(s&31))))
 		return false;
-	bit = 1 << s;
+	bit = 1 << (s&31);
 	for(;;) {
-		mask = sig.mask;
+		mask = sig.mask[s/32];
 		if(mask & bit)
 			break;		// signal already in queue
-		if(runtime·cas(&sig.mask, mask, mask|bit)) {
+		if(runtime·cas(&sig.mask[s/32], mask, mask|bit)) {
 			// Added to queue.
-			// Only send a wakeup for the first signal in each round.
-			if(mask == 0)
+			// Only send a wakeup if the receiver needs a kick.
+			if(runtime·cas(&sig.kick, 1, 0))
 				runtime·notewakeup(&sig);
 			break;
 		}
@@ -76,24 +73,77 @@ runtime·sigsend(int32 s)
 	return true;
 }
 
-// Called to receive a bitmask of queued signals.
-func Sigrecv() (m uint32) {
-	runtime·entersyscall();
-	runtime·notesleep(&sig);
-	runtime·exitsyscall();
-	runtime·noteclear(&sig);
+// Called to receive the next queued signal.
+// Must only be called from a single goroutine at a time.
+func signal_recv() (m uint32) {
+	static uint32 recv[nelem(sig.mask)];
+	int32 i, more;
+	
 	for(;;) {
-		m = sig.mask;
-		if(runtime·cas(&sig.mask, m, 0))
-			break;
+		// Serve from local copy if there are bits left.
+		for(i=0; i<NSIG; i++) {
+			if(recv[i/32]&(1U<<(i&31))) {
+				recv[i/32] ^= 1U<<(i&31);
+				m = i;
+				goto done;
+			}
+		}
+
+		// Get a new local copy.
+		// Ask for a kick if more signals come in
+		// during or after our check (before the sleep).
+		if(sig.kick == 0) {
+			runtime·noteclear(&sig);
+			runtime·cas(&sig.kick, 0, 1);
+		}
+
+		more = 0;
+		for(i=0; i<nelem(sig.mask); i++) {
+			for(;;) {
+				m = sig.mask[i];
+				if(runtime·cas(&sig.mask[i], m, 0))
+					break;
+			}
+			recv[i] = m;
+			if(m != 0)
+				more = 1;
+		}
+		if(more)
+			continue;
+
+		// Sleep waiting for more.
+		runtime·entersyscall();
+		runtime·notesleep(&sig);
+		runtime·exitsyscall();
 	}
-}
 
-func Signame(sig int32) (name String) {
-	name = runtime·signame(sig);
+done:;
+	// goc requires that we fall off the end of functions
+	// that return values instead of using our own return
+	// statements.
 }
 
-func Siginit() {
-	runtime·initsig(SigQueue);
-	sig.inuse = true;	// enable reception of signals; cannot disable
+// Must only be called from a single goroutine at a time.
+func signal_enable(s uint32) {
+	int32 i;
+
+	if(!sig.inuse) {
+		// The first call to signal_enable is for us
+		// to use for initialization.  It does not pass
+		// signal information in m.
+		sig.inuse = true;	// enable reception of signals; cannot disable
+		runtime·noteclear(&sig);
+		return;
+	}
+	
+	if(~s == 0) {
+		// Special case: want everything.
+		for(i=0; i<nelem(sig.wanted); i++)
+			sig.wanted[i] = ~(uint32)0;
+		return;
+	}
+
+	if(s >= nelem(sig.wanted)*32)
+		return;
+	sig.wanted[s/32] |= 1U<<(s&31);
 }
diff --git a/src/pkg/runtime/sys_linux_386.s b/src/pkg/runtime/sys_linux_386.s
index b745bc502e..bee785407f 100644
--- a/src/pkg/runtime/sys_linux_386.s
+++ b/src/pkg/runtime/sys_linux_386.s
@@ -175,9 +175,6 @@ TEXT runtime·sigtramp(SB),7,$44
 
 	RET
 
-TEXT runtime·sigignore(SB),7,$0
-	RET
-
 TEXT runtime·sigreturn(SB),7,$0
 	MOVL	$173, AX	// rt_sigreturn
 	// Sigreturn expects same SP as signal handler,
diff --git a/src/pkg/runtime/sys_linux_amd64.s b/src/pkg/runtime/sys_linux_amd64.s
index ef7bb2864c..68c2bf0eb7 100644
--- a/src/pkg/runtime/sys_linux_amd64.s
+++ b/src/pkg/runtime/sys_linux_amd64.s
@@ -157,9 +157,6 @@ TEXT runtime·sigtramp(SB),7,$64
 	MOVQ	R10, g(BX)
 	RET
 
-TEXT runtime·sigignore(SB),7,$0
-	RET
-
 TEXT runtime·sigreturn(SB),7,$0
 	MOVL	$15, AX	// rt_sigreturn
 	SYSCALL
diff --git a/src/pkg/runtime/sys_linux_arm.s b/src/pkg/runtime/sys_linux_arm.s
index c3a828a924..8f30bff94b 100644
--- a/src/pkg/runtime/sys_linux_arm.s
+++ b/src/pkg/runtime/sys_linux_arm.s
@@ -271,9 +271,6 @@ TEXT runtime·sigaltstack(SB),7,$0
 	SWI	$0
 	RET
 
-TEXT runtime·sigignore(SB),7,$0
-	RET
-
 TEXT runtime·sigtramp(SB),7,$24
 	// save g
 	MOVW	g, R3
diff --git a/src/pkg/runtime/thread_plan9.c b/src/pkg/runtime/thread_plan9.c
index a9b156d028..1180fc880a 100644
--- a/src/pkg/runtime/thread_plan9.c
+++ b/src/pkg/runtime/thread_plan9.c
@@ -48,7 +48,7 @@ runtime·goenvs(void)
 }
 
 void
-runtime·initsig(int32)
+runtime·initsig(void)
 {
 }