1 files changed, 76 insertions, 0 deletions
diff --git a/runsc/boot/compat.go b/runsc/boot/compat.go
new file mode 100644
index 000000000..3250cdcdc
--- /dev/null
+++ b/runsc/boot/compat.go
@@ -0,0 +1,76 @@
+// Copyright 2018 Google Inc.
+//
+// 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 boot
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/golang/protobuf/proto"
+	"gvisor.googlesource.com/gvisor/pkg/abi"
+	"gvisor.googlesource.com/gvisor/pkg/eventchannel"
+	"gvisor.googlesource.com/gvisor/pkg/log"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
+	rpb "gvisor.googlesource.com/gvisor/pkg/sentry/arch/registers_go_proto"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/strace"
+	spb "gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/unimplemented_syscall_go_proto"
+)
+
+func initCompatLogs(fd int) error {
+	ce, err := newCompatEmitter(fd)
+	if err != nil {
+		return err
+	}
+	eventchannel.AddEmitter(ce)
+	return nil
+}
+
+type compatEmitter struct {
+	sink    *log.BasicLogger
+	nameMap strace.SyscallMap
+}
+
+func newCompatEmitter(logFD int) (*compatEmitter, error) {
+	// Always logs to default logger.
+	nameMap, ok := strace.Lookup(abi.Linux, arch.AMD64)
+	if !ok {
+		return nil, fmt.Errorf("amd64 Linux syscall table not found")
+	}
+	c := &compatEmitter{sink: log.Log(), nameMap: nameMap}
+
+	if logFD > 0 {
+		f := os.NewFile(uintptr(logFD), "user log file")
+		target := log.MultiEmitter{c.sink, log.GoogleEmitter{&log.Writer{Next: f}}}
+		c.sink = &log.BasicLogger{Level: log.Info, Emitter: target}
+	}
+	return c, nil
+}
+
+// Emit implements eventchannel.Emitter.
+func (c *compatEmitter) Emit(msg proto.Message) (hangup bool, err error) {
+	// Only interested in UnimplementedSyscall, skip the rest.
+	if us, ok := msg.(*spb.UnimplementedSyscall); ok {
+		regs := us.Registers.GetArch().(*rpb.Registers_Amd64).Amd64
+		sysnr := regs.OrigRax
+		c.sink.Infof("Unsupported syscall: %s, regs: %+v", c.nameMap.Name(uintptr(sysnr)), regs)
+	}
+	return false, nil
+}
+
+// Close implements eventchannel.Emitter.
+func (c *compatEmitter) Close() error {
+	c.sink = nil
+	return nil
+}