1 // Copyright 2022 The gVisor Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 15 //go:build arm64
16 // +build arm64
17 18 package atomicbitops
19 20 import (
21 "runtime"
22 23 "golang.org/x/sys/cpu"
24 "gvisor.dev/gvisor/pkg/cpuid"
25 )
26 27 var arm64HasATOMICS bool
28 29 func init() {
30 // The gvisor cpuid package only works on Linux.
31 // For all other operating systems, use Go's x/sys/cpu package
32 // to get the one bit we care about here.
33 //
34 // See https://github.com/google/gvisor/issues/7849.
35 if runtime.GOOS == "linux" {
36 arm64HasATOMICS = cpuid.HostFeatureSet().HasFeature(cpuid.ARM64FeatureATOMICS)
37 } else {
38 arm64HasATOMICS = cpu.ARM64.HasATOMICS
39 }
40 }
41