libgo: Update to Go 1.3 release.

From-SVN: r212837

16 files changed, 605 insertions, 131 deletions

diff --git a/libgo/go/runtime/chan_test.go b/libgo/go/runtime/chan_test.go
index 782176c8836..ce4b3962717 100644
--- a/libgo/go/runtime/chan_test.go
+++ b/libgo/go/runtime/chan_test.go
@@ -431,27 +431,15 @@ func TestMultiConsumer(t *testing.T) {
 }
 
 func BenchmarkChanNonblocking(b *testing.B) {
-	const CallsPerSched = 1000
-	procs := runtime.GOMAXPROCS(-1)
-	N := int32(b.N / CallsPerSched)
-	c := make(chan bool, procs)
 	myc := make(chan int)
-	for p := 0; p < procs; p++ {
-		go func() {
-			for atomic.AddInt32(&N, -1) >= 0 {
-				for g := 0; g < CallsPerSched; g++ {
-					select {
-					case <-myc:
-					default:
-					}
-				}
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			select {
+			case <-myc:
+			default:
 			}
-			c <- true
-		}()
-	}
-	for p := 0; p < procs; p++ {
-		<-c
-	}
+		}
+	})
 }
 
 func BenchmarkSelectUncontended(b *testing.B) {
@@ -713,23 +701,11 @@ func BenchmarkChanCreation(b *testing.B) {
 
 func BenchmarkChanSem(b *testing.B) {
 	type Empty struct{}
-	const CallsPerSched = 1000
-	procs := runtime.GOMAXPROCS(0)
-	N := int32(b.N / CallsPerSched)
-	c := make(chan bool, procs)
-	myc := make(chan Empty, procs)
-	for p := 0; p < procs; p++ {
-		go func() {
-			for atomic.AddInt32(&N, -1) >= 0 {
-				for g := 0; g < CallsPerSched; g++ {
-					myc <- Empty{}
-					<-myc
-				}
-			}
-			c <- true
-		}()
-	}
-	for p := 0; p < procs; p++ {
-		<-c
-	}
+	myc := make(chan Empty, runtime.GOMAXPROCS(0))
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			myc <- Empty{}
+			<-myc
+		}
+	})
 }
diff --git a/libgo/go/runtime/crash_test.go b/libgo/go/runtime/crash_test.go
index d8bfdbdad6d..39e04345a10 100644
--- a/libgo/go/runtime/crash_test.go
+++ b/libgo/go/runtime/crash_test.go
@@ -9,6 +9,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"testing"
 	"text/template"
@@ -32,6 +33,10 @@ func testEnv(cmd *exec.Cmd) *exec.Cmd {
 
 func executeTest(t *testing.T, templ string, data interface{}) string {
 	t.Skip("gccgo does not have a go command")
+	if runtime.GOOS == "nacl" {
+		t.Skip("skipping on nacl")
+	}
+
 	checkStaleRuntime(t)
 
 	st := template.Must(template.New("crashSource").Parse(templ))
@@ -112,8 +117,9 @@ func TestLockedDeadlock2(t *testing.T) {
 
 func TestGoexitDeadlock(t *testing.T) {
 	output := executeTest(t, goexitDeadlockSource, nil)
-	if output != "" {
-		t.Fatalf("expected no output, got:\n%s", output)
+	want := "no goroutines (main called runtime.Goexit) - deadlock!"
+	if !strings.Contains(output, want) {
+		t.Fatalf("output:\n%s\n\nwant output containing: %s", output, want)
 	}
 }
 
@@ -133,6 +139,34 @@ func TestThreadExhaustion(t *testing.T) {
 	}
 }
 
+func TestRecursivePanic(t *testing.T) {
+	output := executeTest(t, recursivePanicSource, nil)
+	want := `wrap: bad
+panic: again
+
+`
+	if !strings.HasPrefix(output, want) {
+		t.Fatalf("output does not start with %q:\n%s", want, output)
+	}
+
+}
+
+func TestGoexitCrash(t *testing.T) {
+	output := executeTest(t, goexitExitSource, nil)
+	want := "no goroutines (main called runtime.Goexit) - deadlock!"
+	if !strings.Contains(output, want) {
+		t.Fatalf("output:\n%s\n\nwant output containing: %s", output, want)
+	}
+}
+
+func TestGoNil(t *testing.T) {
+	output := executeTest(t, goNilSource, nil)
+	want := "go of nil func value"
+	if !strings.Contains(output, want) {
+		t.Fatalf("output:\n%s\n\nwant output containing: %s", output, want)
+	}
+}
+
 const crashSource = `
 package main
 
@@ -273,3 +307,61 @@ func main() {
 	}
 }
 `
+
+const recursivePanicSource = `
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	func() {
+		defer func() {
+			fmt.Println(recover())
+		}()
+		var x [8192]byte
+		func(x [8192]byte) {
+			defer func() {
+				if err := recover(); err != nil {
+					panic("wrap: " + err.(string))
+				}
+			}()
+			panic("bad")
+		}(x)
+	}()
+	panic("again")
+}
+`
+
+const goexitExitSource = `
+package main
+
+import (
+	"runtime"
+	"time"
+)
+
+func main() {
+	go func() {
+		time.Sleep(time.Millisecond)
+	}()
+	i := 0
+	runtime.SetFinalizer(&i, func(p *int) {})
+	runtime.GC()
+	runtime.Goexit()
+}
+`
+
+const goNilSource = `
+package main
+
+func main() {
+	defer func() {
+		recover()
+	}()
+	var f func()
+	go f()
+	select{}
+}
+`
diff --git a/libgo/go/runtime/debug/garbage.go b/libgo/go/runtime/debug/garbage.go
index a724fdf8f60..edb3643871e 100644
--- a/libgo/go/runtime/debug/garbage.go
+++ b/libgo/go/runtime/debug/garbage.go
@@ -135,3 +135,19 @@ func SetMaxStack(bytes int) int {
 func SetMaxThreads(threads int) int {
 	return setMaxThreads(threads)
 }
+
+// SetPanicOnFault controls the runtime's behavior when a program faults
+// at an unexpected (non-nil) address. Such faults are typically caused by
+// bugs such as runtime memory corruption, so the default response is to crash
+// the program. Programs working with memory-mapped files or unsafe
+// manipulation of memory may cause faults at non-nil addresses in less
+// dramatic situations; SetPanicOnFault allows such programs to request
+// that the runtime trigger only a panic, not a crash.
+// SetPanicOnFault applies only to the current goroutine.
+// It returns the previous setting.
+func SetPanicOnFault(enabled bool) bool
+
+// WriteHeapDump writes a description of the heap and the objects in
+// it to the given file descriptor.
+// The heap dump format is defined at http://golang.org/s/go13heapdump.
+func WriteHeapDump(fd uintptr)
diff --git a/libgo/go/runtime/debug/heapdump_test.go b/libgo/go/runtime/debug/heapdump_test.go
new file mode 100644
index 00000000000..9201901151f
--- /dev/null
+++ b/libgo/go/runtime/debug/heapdump_test.go
@@ -0,0 +1,33 @@
+// Copyright 2014 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 debug
+
+import (
+	"io/ioutil"
+	"os"
+	"runtime"
+	"testing"
+)
+
+func TestWriteHeapDumpNonempty(t *testing.T) {
+	if runtime.GOOS == "nacl" {
+		t.Skip("WriteHeapDump is not available on NaCl.")
+	}
+	f, err := ioutil.TempFile("", "heapdumptest")
+	if err != nil {
+		t.Fatalf("TempFile failed: %v", err)
+	}
+	defer os.Remove(f.Name())
+	defer f.Close()
+	WriteHeapDump(f.Fd())
+	fi, err := f.Stat()
+	if err != nil {
+		t.Fatalf("Stat failed: %v", err)
+	}
+	const minSize = 1
+	if size := fi.Size(); size < minSize {
+		t.Fatalf("Heap dump size %d bytes, expected at least %d bytes", size, minSize)
+	}
+}
diff --git a/libgo/go/runtime/extern.go b/libgo/go/runtime/extern.go
index 85b69cfdcfc..333d4fd000f 100644
--- a/libgo/go/runtime/extern.go
+++ b/libgo/go/runtime/extern.go
@@ -36,6 +36,9 @@ a comma-separated list of name=val pairs. Supported names are:
 	length of the pause. Setting gctrace=2 emits the same summary but also
 	repeats each collection.
 
+	gcdead: setting gcdead=1 causes the garbage collector to clobber all stack slots
+	that it thinks are dead.
+
 	scheddetail: setting schedtrace=X and scheddetail=1 causes the scheduler to emit
 	detailed multiline info every X milliseconds, describing state of the scheduler,
 	processors, threads and goroutines.
@@ -76,6 +79,11 @@ func Gosched()
 
 // Goexit terminates the goroutine that calls it.  No other goroutine is affected.
 // Goexit runs all deferred calls before terminating the goroutine.
+//
+// Calling Goexit from the main goroutine terminates that goroutine
+// without func main returning. Since func main has not returned,
+// the program continues execution of other goroutines.
+// If all other goroutines exit, the program crashes.
 func Goexit()
 
 // Caller reports file and line number information about function invocations on
@@ -182,10 +190,8 @@ func GOROOT() string {
 }
 
 // Version returns the Go tree's version string.
-// It is either a sequence number or, when possible,
-// a release tag like "release.2010-03-04".
-// A trailing + indicates that the tree had local modifications
-// at the time of the build.
+// It is either the commit hash and date at the time of the build or,
+// when possible, a release tag like "go1.3".
 func Version() string {
 	return theVersion
 }
diff --git a/libgo/go/runtime/gc_test.go b/libgo/go/runtime/gc_test.go
index 1b3ccbf7d93..5a1e9b89c42 100644
--- a/libgo/go/runtime/gc_test.go
+++ b/libgo/go/runtime/gc_test.go
@@ -9,6 +9,7 @@ import (
 	"runtime"
 	"runtime/debug"
 	"testing"
+	"time"
 )
 
 func TestGcSys(t *testing.T) {
@@ -153,3 +154,85 @@ func TestGcRescan(t *testing.T) {
 		}
 	}
 }
+
+func TestGcLastTime(t *testing.T) {
+	ms := new(runtime.MemStats)
+	t0 := time.Now().UnixNano()
+	runtime.GC()
+	t1 := time.Now().UnixNano()
+	runtime.ReadMemStats(ms)
+	last := int64(ms.LastGC)
+	if t0 > last || last > t1 {
+		t.Fatalf("bad last GC time: got %v, want [%v, %v]", last, t0, t1)
+	}
+}
+
+func BenchmarkSetTypeNoPtr1(b *testing.B) {
+	type NoPtr1 struct {
+		p uintptr
+	}
+	var p *NoPtr1
+	for i := 0; i < b.N; i++ {
+		p = &NoPtr1{}
+	}
+	_ = p
+}
+func BenchmarkSetTypeNoPtr2(b *testing.B) {
+	type NoPtr2 struct {
+		p, q uintptr
+	}
+	var p *NoPtr2
+	for i := 0; i < b.N; i++ {
+		p = &NoPtr2{}
+	}
+	_ = p
+}
+func BenchmarkSetTypePtr1(b *testing.B) {
+	type Ptr1 struct {
+		p *byte
+	}
+	var p *Ptr1
+	for i := 0; i < b.N; i++ {
+		p = &Ptr1{}
+	}
+	_ = p
+}
+func BenchmarkSetTypePtr2(b *testing.B) {
+	type Ptr2 struct {
+		p, q *byte
+	}
+	var p *Ptr2
+	for i := 0; i < b.N; i++ {
+		p = &Ptr2{}
+	}
+	_ = p
+}
+
+func BenchmarkAllocation(b *testing.B) {
+	type T struct {
+		x, y *byte
+	}
+	ngo := runtime.GOMAXPROCS(0)
+	work := make(chan bool, b.N+ngo)
+	result := make(chan *T)
+	for i := 0; i < b.N; i++ {
+		work <- true
+	}
+	for i := 0; i < ngo; i++ {
+		work <- false
+	}
+	for i := 0; i < ngo; i++ {
+		go func() {
+			var x *T
+			for <-work {
+				for i := 0; i < 1000; i++ {
+					x = &T{}
+				}
+			}
+			result <- x
+		}()
+	}
+	for i := 0; i < ngo; i++ {
+		<-result
+	}
+}
diff --git a/libgo/go/runtime/map_test.go b/libgo/go/runtime/map_test.go
index fe5d3ad86c9..d9690253582 100644
--- a/libgo/go/runtime/map_test.go
+++ b/libgo/go/runtime/map_test.go
@@ -449,3 +449,43 @@ func TestMapIterOrder(t *testing.T) {
 		}
 	}
 }
+
+func TestMapStringBytesLookup(t *testing.T) {
+	if runtime.Compiler == "gccgo" {
+		t.Skip("skipping for gccgo")
+	}
+	// Use large string keys to avoid small-allocation coalescing,
+	// which can cause AllocsPerRun to report lower counts than it should.
+	m := map[string]int{
+		"1000000000000000000000000000000000000000000000000": 1,
+		"2000000000000000000000000000000000000000000000000": 2,
+	}
+	buf := []byte("1000000000000000000000000000000000000000000000000")
+	if x := m[string(buf)]; x != 1 {
+		t.Errorf(`m[string([]byte("1"))] = %d, want 1`, x)
+	}
+	buf[0] = '2'
+	if x := m[string(buf)]; x != 2 {
+		t.Errorf(`m[string([]byte("2"))] = %d, want 2`, x)
+	}
+
+	var x int
+	n := testing.AllocsPerRun(100, func() {
+		x += m[string(buf)]
+	})
+	if n != 0 {
+		t.Errorf("AllocsPerRun for m[string(buf)] = %v, want 0", n)
+	}
+
+	x = 0
+	n = testing.AllocsPerRun(100, func() {
+		y, ok := m[string(buf)]
+		if !ok {
+			panic("!ok")
+		}
+		x += y
+	})
+	if n != 0 {
+		t.Errorf("AllocsPerRun for x,ok = m[string(buf)] = %v, want 0", n)
+	}
+}
diff --git a/libgo/go/runtime/memmove_test.go b/libgo/go/runtime/memmove_test.go
index 5c01aac97a9..540f0feb549 100644
--- a/libgo/go/runtime/memmove_test.go
+++ b/libgo/go/runtime/memmove_test.go
@@ -161,3 +161,83 @@ func BenchmarkMemclr64(b *testing.B)    { bmMemclr(b, 64) }
 func BenchmarkMemclr256(b *testing.B)   { bmMemclr(b, 256) }
 func BenchmarkMemclr4096(b *testing.B)  { bmMemclr(b, 4096) }
 func BenchmarkMemclr65536(b *testing.B) { bmMemclr(b, 65536) }
+
+func BenchmarkClearFat32(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var x [32]byte
+		_ = x
+	}
+}
+func BenchmarkClearFat64(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var x [64]byte
+		_ = x
+	}
+}
+func BenchmarkClearFat128(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var x [128]byte
+		_ = x
+	}
+}
+func BenchmarkClearFat256(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var x [256]byte
+		_ = x
+	}
+}
+func BenchmarkClearFat512(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var x [512]byte
+		_ = x
+	}
+}
+func BenchmarkClearFat1024(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		var x [1024]byte
+		_ = x
+	}
+}
+
+func BenchmarkCopyFat32(b *testing.B) {
+	var x [32 / 4]uint32
+	for i := 0; i < b.N; i++ {
+		y := x
+		_ = y
+	}
+}
+func BenchmarkCopyFat64(b *testing.B) {
+	var x [64 / 4]uint32
+	for i := 0; i < b.N; i++ {
+		y := x
+		_ = y
+	}
+}
+func BenchmarkCopyFat128(b *testing.B) {
+	var x [128 / 4]uint32
+	for i := 0; i < b.N; i++ {
+		y := x
+		_ = y
+	}
+}
+func BenchmarkCopyFat256(b *testing.B) {
+	var x [256 / 4]uint32
+	for i := 0; i < b.N; i++ {
+		y := x
+		_ = y
+	}
+}
+func BenchmarkCopyFat512(b *testing.B) {
+	var x [512 / 4]uint32
+	for i := 0; i < b.N; i++ {
+		y := x
+		_ = y
+	}
+}
+func BenchmarkCopyFat1024(b *testing.B) {
+	var x [1024 / 4]uint32
+	for i := 0; i < b.N; i++ {
+		y := x
+		_ = y
+	}
+}
diff --git a/libgo/go/runtime/mfinal_test.go b/libgo/go/runtime/mfinal_test.go
index ffcffbd4bef..b47f83c3923 100644
--- a/libgo/go/runtime/mfinal_test.go
+++ b/libgo/go/runtime/mfinal_test.go
@@ -6,10 +6,9 @@ package runtime_test
 
 import (
 	"runtime"
-	"sync"
-	"sync/atomic"
 	"testing"
 	"time"
+	"unsafe"
 )
 
 type Tintptr *int // assignable to *int
@@ -112,50 +111,133 @@ func TestFinalizerZeroSizedStruct(t *testing.T) {
 }
 
 func BenchmarkFinalizer(b *testing.B) {
-	const CallsPerSched = 1000
-	procs := runtime.GOMAXPROCS(-1)
-	N := int32(b.N / CallsPerSched)
-	var wg sync.WaitGroup
-	wg.Add(procs)
-	for p := 0; p < procs; p++ {
-		go func() {
-			var data [CallsPerSched]*int
-			for i := 0; i < CallsPerSched; i++ {
-				data[i] = new(int)
+	const Batch = 1000
+	b.RunParallel(func(pb *testing.PB) {
+		var data [Batch]*int
+		for i := 0; i < Batch; i++ {
+			data[i] = new(int)
+		}
+		for pb.Next() {
+			for i := 0; i < Batch; i++ {
+				runtime.SetFinalizer(data[i], fin)
 			}
-			for atomic.AddInt32(&N, -1) >= 0 {
-				runtime.Gosched()
-				for i := 0; i < CallsPerSched; i++ {
-					runtime.SetFinalizer(data[i], fin)
-				}
-				for i := 0; i < CallsPerSched; i++ {
-					runtime.SetFinalizer(data[i], nil)
-				}
+			for i := 0; i < Batch; i++ {
+				runtime.SetFinalizer(data[i], nil)
 			}
-			wg.Done()
-		}()
-	}
-	wg.Wait()
+		}
+	})
 }
 
 func BenchmarkFinalizerRun(b *testing.B) {
-	const CallsPerSched = 1000
-	procs := runtime.GOMAXPROCS(-1)
-	N := int32(b.N / CallsPerSched)
-	var wg sync.WaitGroup
-	wg.Add(procs)
-	for p := 0; p < procs; p++ {
-		go func() {
-			for atomic.AddInt32(&N, -1) >= 0 {
-				runtime.Gosched()
-				for i := 0; i < CallsPerSched; i++ {
-					v := new(int)
-					runtime.SetFinalizer(v, fin)
-				}
-				runtime.GC()
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			v := new(int)
+			runtime.SetFinalizer(v, fin)
+		}
+	})
+}
+
+// One chunk must be exactly one sizeclass in size.
+// It should be a sizeclass not used much by others, so we
+// have a greater chance of finding adjacent ones.
+// size class 19: 320 byte objects, 25 per page, 1 page alloc at a time
+const objsize = 320
+
+type objtype [objsize]byte
+
+func adjChunks() (*objtype, *objtype) {
+	var s []*objtype
+
+	for {
+		c := new(objtype)
+		for _, d := range s {
+			if uintptr(unsafe.Pointer(c))+unsafe.Sizeof(*c) == uintptr(unsafe.Pointer(d)) {
+				return c, d
 			}
-			wg.Done()
-		}()
+			if uintptr(unsafe.Pointer(d))+unsafe.Sizeof(*c) == uintptr(unsafe.Pointer(c)) {
+				return d, c
+			}
+		}
+		s = append(s, c)
+	}
+}
+
+// Make sure an empty slice on the stack doesn't pin the next object in memory.
+func TestEmptySlice(t *testing.T) {
+	if true { // disable until bug 7564 is fixed.
+		return
+	}
+	x, y := adjChunks()
+
+	// the pointer inside xs points to y.
+	xs := x[objsize:] // change objsize to objsize-1 and the test passes
+
+	fin := make(chan bool, 1)
+	runtime.SetFinalizer(y, func(z *objtype) { fin <- true })
+	runtime.GC()
+	select {
+	case <-fin:
+	case <-time.After(4 * time.Second):
+		t.Errorf("finalizer of next object in memory didn't run")
+	}
+	xsglobal = xs // keep empty slice alive until here
+}
+
+var xsglobal []byte
+
+func adjStringChunk() (string, *objtype) {
+	b := make([]byte, objsize)
+	for {
+		s := string(b)
+		t := new(objtype)
+		p := *(*uintptr)(unsafe.Pointer(&s))
+		q := uintptr(unsafe.Pointer(t))
+		if p+objsize == q {
+			return s, t
+		}
+	}
+}
+
+// Make sure an empty string on the stack doesn't pin the next object in memory.
+func TestEmptyString(t *testing.T) {
+	if runtime.Compiler == "gccgo" {
+		t.Skip("skipping for gccgo")
+	}
+
+	x, y := adjStringChunk()
+
+	ss := x[objsize:] // change objsize to objsize-1 and the test passes
+	fin := make(chan bool, 1)
+	// set finalizer on string contents of y
+	runtime.SetFinalizer(y, func(z *objtype) { fin <- true })
+	runtime.GC()
+	select {
+	case <-fin:
+	case <-time.After(4 * time.Second):
+		t.Errorf("finalizer of next string in memory didn't run")
 	}
-	wg.Wait()
+	ssglobal = ss // keep 0-length string live until here
+}
+
+var ssglobal string
+
+// Test for issue 7656.
+func TestFinalizerOnGlobal(t *testing.T) {
+	runtime.SetFinalizer(Foo1, func(p *Object1) {})
+	runtime.SetFinalizer(Foo2, func(p *Object2) {})
+	runtime.SetFinalizer(Foo1, nil)
+	runtime.SetFinalizer(Foo2, nil)
 }
+
+type Object1 struct {
+	Something []byte
+}
+
+type Object2 struct {
+	Something byte
+}
+
+var (
+	Foo2 = &Object2{}
+	Foo1 = &Object1{}
+)
diff --git a/libgo/go/runtime/mgc0.go b/libgo/go/runtime/mgc0.go
index b1505466222..624485d18bf 100644
--- a/libgo/go/runtime/mgc0.go
+++ b/libgo/go/runtime/mgc0.go
@@ -9,7 +9,19 @@ func gc_m_ptr(ret *interface{}) {
 	*ret = (*m)(nil)
 }
 
+// Called from C. Returns the Go type *g.
+func gc_g_ptr(ret *interface{}) {
+	*ret = (*g)(nil)
+}
+
 // Called from C. Returns the Go type *itab.
 func gc_itab_ptr(ret *interface{}) {
 	*ret = (*itab)(nil)
 }
+
+func timenow() (sec int64, nsec int32)
+
+func gc_unixnanotime(now *int64) {
+	sec, nsec := timenow()
+	*now = sec*1e9 + int64(nsec)
+}
diff --git a/libgo/go/runtime/norace_test.go b/libgo/go/runtime/norace_test.go
index a3d5b00860c..3b171877a6f 100644
--- a/libgo/go/runtime/norace_test.go
+++ b/libgo/go/runtime/norace_test.go
@@ -9,7 +9,6 @@ package runtime_test
 
 import (
 	"runtime"
-	"sync/atomic"
 	"testing"
 )
 
@@ -31,28 +30,17 @@ func BenchmarkSyscallExcessWork(b *testing.B) {
 }
 
 func benchmarkSyscall(b *testing.B, work, excess int) {
-	const CallsPerSched = 1000
-	procs := runtime.GOMAXPROCS(-1) * excess
-	N := int32(b.N / CallsPerSched)
-	c := make(chan bool, procs)
-	for p := 0; p < procs; p++ {
-		go func() {
-			foo := 42
-			for atomic.AddInt32(&N, -1) >= 0 {
-				runtime.Gosched()
-				for g := 0; g < CallsPerSched; g++ {
-					runtime.Entersyscall()
-					for i := 0; i < work; i++ {
-						foo *= 2
-						foo /= 2
-					}
-					runtime.Exitsyscall()
-				}
+	b.SetParallelism(excess)
+	b.RunParallel(func(pb *testing.PB) {
+		foo := 42
+		for pb.Next() {
+			runtime.Entersyscall()
+			for i := 0; i < work; i++ {
+				foo *= 2
+				foo /= 2
 			}
-			c <- foo == 42
-		}()
-	}
-	for p := 0; p < procs; p++ {
-		<-c
-	}
+			runtime.Exitsyscall()
+		}
+		_ = foo
+	})
 }
diff --git a/libgo/go/runtime/pprof/pprof.go b/libgo/go/runtime/pprof/pprof.go
index 98080457cb5..26aa0b8be5c 100644
--- a/libgo/go/runtime/pprof/pprof.go
+++ b/libgo/go/runtime/pprof/pprof.go
@@ -20,7 +20,7 @@ import (
 	"text/tabwriter"
 )
 
-// BUG(rsc): Profiles are incomplete and inaccuate on NetBSD and OS X.
+// BUG(rsc): Profiles are incomplete and inaccurate on NetBSD and OS X.
 // See http://golang.org/issue/6047 for details.
 
 // A Profile is a collection of stack traces showing the call sequences
diff --git a/libgo/go/runtime/pprof/pprof_test.go b/libgo/go/runtime/pprof/pprof_test.go
index cce60e1be3b..f714472fd55 100644
--- a/libgo/go/runtime/pprof/pprof_test.go
+++ b/libgo/go/runtime/pprof/pprof_test.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !nacl
+
 package pprof_test
 
 import (
diff --git a/libgo/go/runtime/proc_test.go b/libgo/go/runtime/proc_test.go
index bdcb199d727..4f364dc4636 100644
--- a/libgo/go/runtime/proc_test.go
+++ b/libgo/go/runtime/proc_test.go
@@ -373,24 +373,11 @@ func TestSchedLocalQueueSteal(t *testing.T) {
 }
 
 func benchmarkStackGrowth(b *testing.B, rec int) {
-	const CallsPerSched = 1000
-	procs := runtime.GOMAXPROCS(-1)
-	N := int32(b.N / CallsPerSched)
-	c := make(chan bool, procs)
-	for p := 0; p < procs; p++ {
-		go func() {
-			for atomic.AddInt32(&N, -1) >= 0 {
-				runtime.Gosched()
-				for g := 0; g < CallsPerSched; g++ {
-					stackGrowthRecursive(rec)
-				}
-			}
-			c <- true
-		}()
-	}
-	for p := 0; p < procs; p++ {
-		<-c
-	}
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			stackGrowthRecursive(rec)
+		}
+	})
 }
 
 func BenchmarkStackGrowth(b *testing.B) {
diff --git a/libgo/go/runtime/runtime_test.go b/libgo/go/runtime/runtime_test.go
index 1702298aed1..7dae95a2d4f 100644
--- a/libgo/go/runtime/runtime_test.go
+++ b/libgo/go/runtime/runtime_test.go
@@ -10,9 +10,11 @@ import (
 	// "os"
 	// "os/exec"
 	// . "runtime"
+	"runtime/debug"
 	// "strconv"
 	// "strings"
 	"testing"
+	"unsafe"
 )
 
 var errf error
@@ -95,10 +97,10 @@ func BenchmarkDeferMany(b *testing.B) {
 // The value reported will include the padding between runtime.gogo and the
 // next function in memory. That's fine.
 func TestRuntimeGogoBytes(t *testing.T) {
-	// TODO(brainman): delete when issue 6973 is fixed.
-	if GOOS == "windows" {
-		t.Skip("skipping broken test on windows")
+	if GOOS == "nacl" {
+		t.Skip("skipping on nacl")
 	}
+
 	dir, err := ioutil.TempDir("", "go-build")
 	if err != nil {
 		t.Fatalf("failed to create temp directory: %v", err)
@@ -134,3 +136,77 @@ func TestRuntimeGogoBytes(t *testing.T) {
 func TestStopCPUProfilingWithProfilerOff(t *testing.T) {
 	SetCPUProfileRate(0)
 }
+
+// Addresses to test for faulting behavior.
+// This is less a test of SetPanicOnFault and more a check that
+// the operating system and the runtime can process these faults
+// correctly. That is, we're indirectly testing that without SetPanicOnFault
+// these would manage to turn into ordinary crashes.
+// Note that these are truncated on 32-bit systems, so the bottom 32 bits
+// of the larger addresses must themselves be invalid addresses.
+// We might get unlucky and the OS might have mapped one of these
+// addresses, but probably not: they're all in the first page, very high
+// adderesses that normally an OS would reserve for itself, or malformed
+// addresses. Even so, we might have to remove one or two on different
+// systems. We will see.
+
+var faultAddrs = []uint64{
+	// low addresses
+	0,
+	1,
+	0xfff,
+	// high (kernel) addresses
+	// or else malformed.
+	0xffffffffffffffff,
+	0xfffffffffffff001,
+	// no 0xffffffffffff0001; 0xffff0001 is mapped for 32-bit user space on OS X
+	// no 0xfffffffffff00001; 0xfff00001 is mapped for 32-bit user space sometimes on Linux
+	0xffffffffff000001,
+	0xfffffffff0000001,
+	0xffffffff00000001,
+	0xfffffff000000001,
+	0xffffff0000000001,
+	0xfffff00000000001,
+	0xffff000000000001,
+	0xfff0000000000001,
+	0xff00000000000001,
+	0xf000000000000001,
+	0x8000000000000001,
+}
+
+func TestSetPanicOnFault(t *testing.T) {
+	// This currently results in a fault in the signal trampoline on
+	// dragonfly/386 - see issue 7421.
+	if GOOS == "dragonfly" && GOARCH == "386" {
+		t.Skip("skipping test on dragonfly/386")
+	}
+
+	old := debug.SetPanicOnFault(true)
+	defer debug.SetPanicOnFault(old)
+
+	for _, addr := range faultAddrs {
+		if Compiler == "gccgo" && GOARCH == "386" && (addr&0xff000000) != 0 {
+			// On gccgo these addresses can be used for
+			// the thread stack.
+			continue
+		}
+		testSetPanicOnFault(t, uintptr(addr))
+	}
+}
+
+func testSetPanicOnFault(t *testing.T, addr uintptr) {
+	if GOOS == "nacl" {
+		t.Skip("nacl doesn't seem to fault on high addresses")
+	}
+
+	defer func() {
+		if err := recover(); err == nil {
+			t.Fatalf("did not find error in recover")
+		}
+	}()
+
+	var p *int
+	p = (*int)(unsafe.Pointer(addr))
+	println(*p)
+	t.Fatalf("still here - should have faulted on address %#x", addr)
+}
diff --git a/libgo/go/runtime/type.go b/libgo/go/runtime/type.go
index eba34e4a6ba..1211f222575 100644
--- a/libgo/go/runtime/type.go
+++ b/libgo/go/runtime/type.go
@@ -27,6 +27,7 @@ type rtype struct {
 	string *string
 	*uncommonType
 	ptrToThis *rtype
+	zero      unsafe.Pointer
 }
 
 type _method struct {