4 files changed, 120 insertions, 0 deletions
diff --git a/pkg/goid/goid.go b/pkg/goid/goid.go
new file mode 100644
index 000000000..17c384cb0
--- /dev/null
+++ b/pkg/goid/goid.go
@@ -0,0 +1,72 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.12
+// +build !go1.17
+
+// Check type signatures when updating Go version.
+
+// Package goid provides the Get function.
+package goid
+
+// Get returns the ID of the current goroutine.
+func Get() int64 {
+	return getg().goid
+}
+
+// Structs from Go runtime. These may change in the future and require
+// updating. These structs are currently the same on both AMD64 and ARM64,
+// but may diverge in the future.
+
+type stack struct {
+	lo uintptr
+	hi uintptr
+}
+
+type gobuf struct {
+	sp   uintptr
+	pc   uintptr
+	g    uintptr
+	ctxt uintptr
+	ret  uint64
+	lr   uintptr
+	bp   uintptr
+}
+
+type g struct {
+	stack       stack
+	stackguard0 uintptr
+	stackguard1 uintptr
+
+	_panic       uintptr
+	_defer       uintptr
+	m            uintptr
+	sched        gobuf
+	syscallsp    uintptr
+	syscallpc    uintptr
+	stktopsp     uintptr
+	param        uintptr
+	atomicstatus uint32
+	stackLock    uint32
+	goid         int64
+
+	// More fields...
+	//
+	// We only use goid and the fields before it are only listed to
+	// calculate the correct offset.
+}
+
+// Defined in assembly. This can't use go:linkname since runtime.getg() isn't a
+// real function, it's a compiler intrinsic.
+func getg() *g
diff --git a/pkg/goid/goid_amd64.s b/pkg/goid/goid_amd64.s
new file mode 100644
index 000000000..d9f5cd2a3
--- /dev/null
+++ b/pkg/goid/goid_amd64.s
@@ -0,0 +1,21 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "textflag.h"
+
+// func getg() *g
+TEXT ·getg(SB),NOSPLIT,$0-8
+	MOVQ (TLS), R14
+	MOVQ R14, ret+0(FP)
+	RET
diff --git a/pkg/goid/goid_arm64.s b/pkg/goid/goid_arm64.s
new file mode 100644
index 000000000..a7465b75d
--- /dev/null
+++ b/pkg/goid/goid_arm64.s
@@ -0,0 +1,21 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "textflag.h"
+
+// func getg() *g
+TEXT ·getg(SB),NOSPLIT,$0-8
+        MOVD g, R0      // g
+        MOVD R0, ret+0(FP)
+        RET
diff --git a/pkg/goid/goid_state_autogen.go b/pkg/goid/goid_state_autogen.go
new file mode 100644
index 000000000..a461704fc
--- /dev/null
+++ b/pkg/goid/goid_state_autogen.go
@@ -0,0 +1,6 @@
+// automatically generated by stateify.
+
+// +build go1.12
+// +build !go1.17
+
+package goid