runtime, runtime/msan: add msan runtime support

These are the runtime support functions for letting Go code interoperate
with the C/C++ memory sanitizer.  Calls to msanread/msanwrite are now
inserted by the compiler with the -msan option.  Calls to
msanmalloc/msanfree will be from other runtime functions in a subsequent
CL.

Change-Id: I64fb061b38cc6519153face242eccd291c07d1f2
Reviewed-on: https://go-review.googlesource.com/16162
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/src/runtime/msan.go b/src/runtime/msan.go
new file mode 100644
index 0000000000..7457fe1150
--- /dev/null
+++ b/src/runtime/msan.go
@@ -0,0 +1,42 @@
+// Copyright 2015 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.
+
+// +build msan
+
+package runtime
+
+import (
+	"unsafe"
+)
+
+// Public memory sanitizer API.
+
+func MSanRead(addr unsafe.Pointer, len int) {
+	msanread(addr, uintptr(len))
+}
+
+func MSanWrite(addr unsafe.Pointer, len int) {
+	msanwrite(addr, uintptr(len))
+}
+
+// Private interface for the runtime.
+const msanenabled = true
+
+//go:noescape
+func msanread(addr unsafe.Pointer, sz uintptr)
+
+//go:noescape
+func msanwrite(addr unsafe.Pointer, sz uintptr)
+
+//go:noescape
+func msanmalloc(addr unsafe.Pointer, sz uintptr)
+
+//go:noescape
+func msanfree(addr unsafe.Pointer, sz uintptr)
+
+// These are called from msan_amd64.s
+//go:cgo_import_static __msan_read_go
+//go:cgo_import_static __msan_write_go
+//go:cgo_import_static __msan_malloc_go
+//go:cgo_import_static __msan_free_go