diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index ca47d87b427..205ead9d553 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-70bd9801911f8ed27df410d36a928166c37a68fd
+baf07c40960dc4f8df9da97281870d80d4245b18
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/libgo/go/runtime/proc.go b/libgo/go/runtime/proc.go
index 74325e3974b..12d7071c3c0 100644
--- a/libgo/go/runtime/proc.go
+++ b/libgo/go/runtime/proc.go
@@ -1140,7 +1140,7 @@ func startTheWorldWithSema(emitTraceEvent bool) int64 {
 func kickoff() {
 	gp := getg()
 
-	if gp.traceback != nil {
+	if gp.traceback != 0 {
 		gtraceback(gp)
 	}
 
@@ -3097,7 +3097,7 @@ func newproc(fn uintptr, arg unsafe.Pointer) *g {
 	} else {
 		resetNewG(newg, &sp, &spsize)
 	}
-	newg.traceback = nil
+	newg.traceback = 0
 
 	if readgstatus(newg) != _Gdead {
 		throw("newproc1: new g is not Gdead")
diff --git a/libgo/go/runtime/runtime2.go b/libgo/go/runtime/runtime2.go
index 0299d5a788f..2de1cc8d725 100644
--- a/libgo/go/runtime/runtime2.go
+++ b/libgo/go/runtime/runtime2.go
@@ -431,7 +431,7 @@ type g struct {
 
 	isSystemGoroutine bool // whether goroutine is a "system" goroutine
 
-	traceback *tracebackg // stack traceback buffer
+	traceback uintptr // stack traceback buffer
 
 	context      g_ucontext_t // saved context for setcontext
 	stackcontext [10]uintptr  // split-stack context
diff --git a/libgo/go/runtime/trace.go b/libgo/go/runtime/trace.go
index 8427e76c5a3..e2bbb5d52ab 100644
--- a/libgo/go/runtime/trace.go
+++ b/libgo/go/runtime/trace.go
@@ -135,6 +135,7 @@ var trace struct {
 }
 
 // traceBufHeader is per-P tracing buffer.
+//go:notinheap
 type traceBufHeader struct {
 	link      traceBufPtr              // in trace.empty/full
 	lastTicks uint64                   // when we wrote the last event
@@ -747,7 +748,8 @@ func (tab *traceStackTable) put(pcs []location) uint32 {
 	stk.n = len(pcs)
 	stkpc := stk.stack()
 	for i, pc := range pcs {
-		stkpc[i] = pc
+		// Use memmove to avoid write barrier.
+		memmove(unsafe.Pointer(&stkpc[i]), unsafe.Pointer(&pc), unsafe.Sizeof(pc))
 	}
 	part := int(hash % uintptr(len(tab.tab)))
 	stk.link = tab.tab[part]
diff --git a/libgo/go/runtime/traceback_gccgo.go b/libgo/go/runtime/traceback_gccgo.go
index 8551ec19ac3..9456b1f4b3d 100644
--- a/libgo/go/runtime/traceback_gccgo.go
+++ b/libgo/go/runtime/traceback_gccgo.go
@@ -186,7 +186,7 @@ func tracebackothers(me *g) {
 	if gp != nil && gp != me {
 		print("\n")
 		goroutineheader(gp)
-		gp.traceback = (*tracebackg)(noescape(unsafe.Pointer(&tb)))
+		gp.traceback = (uintptr)(noescape(unsafe.Pointer(&tb)))
 		getTraceback(me, gp)
 		printtrace(tb.locbuf[:tb.c], nil)
 		printcreatedby(gp)
@@ -220,7 +220,7 @@ func tracebackothers(me *g) {
 			print("\tgoroutine in C code; stack unavailable\n")
 			printcreatedby(gp)
 		} else {
-			gp.traceback = (*tracebackg)(noescape(unsafe.Pointer(&tb)))
+			gp.traceback = (uintptr)(noescape(unsafe.Pointer(&tb)))
 			getTraceback(me, gp)
 			printtrace(tb.locbuf[:tb.c], nil)
 			printcreatedby(gp)
diff --git a/libgo/runtime/proc.c b/libgo/runtime/proc.c
index d8d231bae30..7bd95a061c7 100644
--- a/libgo/runtime/proc.c
+++ b/libgo/runtime/proc.c
@@ -338,7 +338,7 @@ runtime_mcall(FuncVal *fv)
 		gp = runtime_g();
 		mp = gp->m;
 
-		if(gp->traceback != nil)
+		if(gp->traceback != 0)
 			gtraceback(gp);
 	}
 	if (gp == nil || !gp->fromgogo) {
@@ -443,7 +443,7 @@ void getTraceback(G* me, G* gp)
 #endif
 	getcontext(ucontext_arg(&me->context[0]));
 
-	if (gp->traceback != nil) {
+	if (gp->traceback != 0) {
 		runtime_gogo(gp);
 	}
 }
@@ -457,8 +457,8 @@ gtraceback(G* gp)
 	Traceback* traceback;
 	M* holdm;
 
-	traceback = gp->traceback;
-	gp->traceback = nil;
+	traceback = (Traceback*)gp->traceback;
+	gp->traceback = 0;
 	holdm = gp->m;
 	if(holdm != nil && holdm != g->m)
 		runtime_throw("gtraceback: m is not nil");
@@ -510,7 +510,7 @@ runtime_mstart(void *arg)
 	// multiple times via the setcontext call in mcall.
 	getcontext(ucontext_arg(&gp->context[0]));
 
-	if(gp->traceback != nil) {
+	if(gp->traceback != 0) {
 		// Got here from getTraceback.
 		// I'm not sure this ever actually happens--getTraceback
 		// may always go to the getcontext call in mcall.