runtime: fix race instrumentation of append

typedslicecopy is another write barrier that is not
understood by racewalk. It seems quite complex to handle it
in the compiler, so instead just instrument it in runtime.

Update #9796

Change-Id: I0eb6abf3a2cd2491a338fab5f7da22f01bf7e89b
Reviewed-on: https://go-review.googlesource.com/4370Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/gc/racewalk.c

@@ -205,6 +205,7 @@ racewalknode(Node **np, NodeList **init, int wr, int skip)
 	case OCALLFUNC:
 		// Instrument dst argument of runtime.writebarrier* calls
 		// as we do not instrument runtime code.
+		// typedslicecopy is instrumented in runtime.
 		if(n->left->sym != S && n->left->sym->pkg == runtimepkg && 
 		(strncmp(n->left->sym->name, "writebarrier", 12) == 0 || strcmp(n->left->sym->name, "typedmemmove") == 0)) {
 			// Find the dst argument.

src/runtime/mbarrier.go

@@ -328,6 +328,13 @@ func typedslicecopy(typ *_type, dst, src slice) int {
 	dstp := unsafe.Pointer(dst.array)
 	srcp := unsafe.Pointer(src.array)
 
+	if raceenabled {
+		callerpc := getcallerpc(unsafe.Pointer(&typ))
+		pc := funcPC(slicecopy)
+		racewriterangepc(dstp, uintptr(n)*typ.size, callerpc, pc)
+		racereadrangepc(srcp, uintptr(n)*typ.size, callerpc, pc)
+	}
+
 	if !needwb() {
 		memmove(dstp, srcp, uintptr(n)*typ.size)
 		return int(n)

src/runtime/race/testdata/slice_test.go

@@ -144,6 +144,54 @@ func TestNoRaceSliceCopyRead(t *testing.T) {
 	<-ch
 }
 
+func TestRacePointerSliceCopyRead(t *testing.T) {
+	ch := make(chan bool, 1)
+	a := make([]*int, 10)
+	b := make([]*int, 10)
+	go func() {
+		_ = a[5]
+		ch <- true
+	}()
+	copy(a, b)
+	<-ch
+}
+
+func TestNoRacePointerSliceWriteCopy(t *testing.T) {
+	ch := make(chan bool, 1)
+	a := make([]*int, 10)
+	b := make([]*int, 10)
+	go func() {
+		a[5] = new(int)
+		ch <- true
+	}()
+	copy(a[:5], b[:5])
+	<-ch
+}
+
+func TestRacePointerSliceCopyWrite2(t *testing.T) {
+	ch := make(chan bool, 1)
+	a := make([]*int, 10)
+	b := make([]*int, 10)
+	go func() {
+		b[5] = new(int)
+		ch <- true
+	}()
+	copy(a, b)
+	<-ch
+}
+
+func TestNoRacePointerSliceCopyRead(t *testing.T) {
+	ch := make(chan bool, 1)
+	a := make([]*int, 10)
+	b := make([]*int, 10)
+	go func() {
+		_ = b[5]
+		ch <- true
+	}()
+	copy(a, b)
+	<-ch
+}
+
 func TestNoRaceSliceWriteSlice2(t *testing.T) {
 	ch := make(chan bool, 1)
 	a := make([]float64, 10)
@@ -395,6 +443,53 @@ func TestRaceSliceAppendString(t *testing.T) {
 	<-c
 }
 
+func TestRacePointerSliceAppend(t *testing.T) {
+	c := make(chan bool, 1)
+	s := make([]*int, 10, 20)
+	go func() {
+		_ = append(s, new(int))
+		c <- true
+	}()
+	_ = append(s, new(int))
+	<-c
+}
+
+func TestRacePointerSliceAppendWrite(t *testing.T) {
+	c := make(chan bool, 1)
+	s := make([]*int, 10)
+	go func() {
+		_ = append(s, new(int))
+		c <- true
+	}()
+	s[0] = new(int)
+	<-c
+}
+
+func TestRacePointerSliceAppendSlice(t *testing.T) {
+	c := make(chan bool, 1)
+	s := make([]*int, 10)
+	go func() {
+		s2 := make([]*int, 10)
+		_ = append(s, s2...)
+		c <- true
+	}()
+	s[0] = new(int)
+	<-c
+}
+
+func TestRacePointerSliceAppendSlice2(t *testing.T) {
+	c := make(chan bool, 1)
+	s := make([]*int, 10)
+	s2foobar := make([]*int, 10)
+	go func() {
+		_ = append(s, s2foobar...)
+		c <- true
+	}()
+	println("WRITE:", &s2foobar[5])
+	s2foobar[5] = nil
+	<-c
+}
+
 func TestNoRaceSliceIndexAccess(t *testing.T) {
 	c := make(chan bool, 1)
 	s := make([]int, 10)