Avoid importing platforms from many source files

PiperOrigin-RevId: 256494243

3 files changed, 49 insertions, 0 deletions

diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD
index 6a1343f47..1b6c54e96 100644
--- a/pkg/sentry/platform/ptrace/BUILD
+++ b/pkg/sentry/platform/ptrace/BUILD
@@ -5,6 +5,7 @@ package(licenses = ["notice"])
 go_library(
     name = "ptrace",
     srcs = [
+        "filters.go",
         "ptrace.go",
         "ptrace_unsafe.go",
         "stub_amd64.s",
diff --git a/pkg/sentry/platform/ptrace/filters.go b/pkg/sentry/platform/ptrace/filters.go
new file mode 100644
index 000000000..1e07cfd0d
--- /dev/null
+++ b/pkg/sentry/platform/ptrace/filters.go
@@ -0,0 +1,33 @@
+// Copyright 2019 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.
+
+package ptrace
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+	"gvisor.dev/gvisor/pkg/seccomp"
+)
+
+// SyscallFilters returns syscalls made exclusively by the ptrace platform.
+func (*PTrace) SyscallFilters() seccomp.SyscallRules {
+	return seccomp.SyscallRules{
+		unix.SYS_GETCPU:            {},
+		unix.SYS_SCHED_SETAFFINITY: {},
+		syscall.SYS_PTRACE:         {},
+		syscall.SYS_TGKILL:         {},
+		syscall.SYS_WAIT4:          {},
+	}
+}
diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go
index ee7e0640c..6fd30ed25 100644
--- a/pkg/sentry/platform/ptrace/ptrace.go
+++ b/pkg/sentry/platform/ptrace/ptrace.go
@@ -45,6 +45,7 @@
 package ptrace
 
 import (
+	"os"
 	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
@@ -236,3 +237,17 @@ func (p *PTrace) NewAddressSpace(_ interface{}) (platform.AddressSpace, <-chan s
 func (*PTrace) NewContext() platform.Context {
 	return &context{}
 }
+
+type constructor struct{}
+
+func (*constructor) New(*os.File) (platform.Platform, error) {
+	return New()
+}
+
+func (*constructor) OpenDevice() (*os.File, error) {
+	return nil, nil
+}
+
+func init() {
+	platform.Register("ptrace", &constructor{})
+}