From ed8cc5cf9bfa9ba6b3ec84ba10028aa0366e0c0c Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Tue, 10 Feb 2015 15:26:07 +0300
Subject: [PATCH] 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/4370
Reviewed-by: Russ Cox <rsc@golang.org>
---
 src/cmd/gc/racewalk.c                   |  1 +
 src/runtime/mbarrier.go                 |  7 ++
 src/runtime/race/testdata/slice_test.go | 95 +++++++++++++++++++++++++
 3 files changed, 103 insertions(+)

diff --git a/src/cmd/gc/racewalk.c b/src/cmd/gc/racewalk.c
index 757b02cb12..3aa7e36386 100644
--- a/src/cmd/gc/racewalk.c
+++ b/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.
diff --git a/src/runtime/mbarrier.go b/src/runtime/mbarrier.go
index 33d67c4976..f6e9269858 100644
--- a/src/runtime/mbarrier.go
+++ b/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)
diff --git a/src/runtime/race/testdata/slice_test.go b/src/runtime/race/testdata/slice_test.go
index 5702d1ac85..32ae878970 100644
--- a/src/runtime/race/testdata/slice_test.go
+++ b/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)
-- 
2.48.1