diff -ur go-orig/src/pkg/runtime/cgocall.c go/src/pkg/runtime/cgocall.c
--- go-orig/src/pkg/runtime/cgocall.c	2014-08-13 12:49:45.000000000 +0900
+++ go/src/pkg/runtime/cgocall.c	2014-08-18 22:32:59.520976303 +0900
@@ -234,14 +234,24 @@
 void
 runtime·cgocallbackg(void)
 {
+	uintptr saved_sp, saved_pc;
+
 	if(g != m->curg) {
 		runtime·prints("runtime: bad g in cgocallback");
 		runtime·exit(2);
 	}
 
+	// entersyscall saves the caller's SP to allow the GC to trace the Go
+	// stack. However, since we're returning to an earlier stack frame and
+	// need to pair with the entersyscall() call made by cgocall, we must
+	// save the syscallsp and syscallpc and restore them before returning.
+	saved_sp = g->syscallsp;
+	saved_pc = g->syscallpc;
 	runtime·exitsyscall();	// coming out of cgo call
 	runtime·cgocallbackg1();
 	runtime·entersyscall();	// going back to cgo call
+	g->syscallsp = saved_sp;
+	g->syscallpc = saved_pc;
 }
 
 void
diff -ur go-orig/src/pkg/runtime/proc.c go/src/pkg/runtime/proc.c
--- go-orig/src/pkg/runtime/proc.c	2014-08-13 12:49:45.000000000 +0900
+++ go/src/pkg/runtime/proc.c	2014-08-18 22:24:38.735585033 +0900
@@ -1588,13 +1588,16 @@
 // from the low-level system calls used by the runtime.
 #pragma textflag NOSPLIT
 void
-runtime·exitsyscall(void)
+·exitsyscall(int32 dummy)
 {
 	m->locks++;  // see comment in entersyscall
 
 	if(g->isbackground)  // do not consider blocked scavenger for deadlock detection
 		incidlelocked(-1);
 
+	if(runtime·getcallersp(&dummy) > g->syscallsp)
+		runtime·throw("runtime: exitsyscall called with invalid syscall frame");
+
 	g->waitsince = 0;
 	if(exitsyscallfast()) {
 		// There's a cpu for us, so we can run.