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authorIan Lance Taylor <iant@golang.org>2015-09-29 21:24:13 -0700
committerIan Lance Taylor <iant@golang.org>2015-09-30 22:17:55 +0000
commit0c1f0549b893d9ddaab42a7765ba82234fbcc10d (patch)
tree6f0e6089d8bdac64096243e33ad7e773f17443a0 /src/runtime/mmap.go
parentb72a4a07c257f394f5a96dff29a4fc862601a41f (diff)
downloadgo-0c1f0549b893d9ddaab42a7765ba82234fbcc10d.tar.gz
go-0c1f0549b893d9ddaab42a7765ba82234fbcc10d.zip
runtime, runtime/cgo: support using msan on cgo code
The memory sanitizer (msan) is a nice compiler feature that can dynamically check for memory errors in C code. It's not useful for Go code, since Go is memory safe. But it is useful to be able to use the memory sanitizer on C code that is linked into a Go program via cgo. Without this change it does not work, as msan considers memory passed from Go to C as uninitialized. To make this work, change the runtime to call the C mmap function when using cgo. When using msan the mmap call will be intercepted and marked as returning initialized memory. Work around what appears to be an msan bug by calling malloc before we call mmap. Change-Id: I8ab7286d7595ae84782f68a98bef6d3688b946f9 Reviewed-on: https://go-review.googlesource.com/15170 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
Diffstat (limited to 'src/runtime/mmap.go')
-rw-r--r--src/runtime/mmap.go16
1 files changed, 16 insertions, 0 deletions
diff --git a/src/runtime/mmap.go b/src/runtime/mmap.go
new file mode 100644
index 0000000000..a0768428b4
--- /dev/null
+++ b/src/runtime/mmap.go
@@ -0,0 +1,16 @@
+// 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 !plan9
+// +build !solaris
+// +build !windows
+// +build !nacl
+// +build !linux !amd64
+
+package runtime
+
+import "unsafe"
+
+// mmap calls the mmap system call. It is implemented in assembly.
+func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uint32) unsafe.Pointer