1 files changed, 72 insertions, 0 deletions
diff --git a/pkg/sentry/strace/poll.go b/pkg/sentry/strace/poll.go
new file mode 100644
index 000000000..b6b05423c
--- /dev/null
+++ b/pkg/sentry/strace/poll.go
@@ -0,0 +1,72 @@
+// Copyright 2019 Google LLC
+//
+// 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 strace
+
+import (
+	"fmt"
+	"strings"
+
+	"gvisor.googlesource.com/gvisor/pkg/abi"
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs"
+	slinux "gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+// PollEventSet is the set of poll(2) event flags.
+var PollEventSet = abi.FlagSet{
+	{Flag: linux.POLLIN, Name: "POLLIN"},
+	{Flag: linux.POLLPRI, Name: "POLLPRI"},
+	{Flag: linux.POLLOUT, Name: "POLLOUT"},
+	{Flag: linux.POLLERR, Name: "POLLERR"},
+	{Flag: linux.POLLHUP, Name: "POLLHUP"},
+	{Flag: linux.POLLNVAL, Name: "POLLNVAL"},
+	{Flag: linux.POLLRDNORM, Name: "POLLRDNORM"},
+	{Flag: linux.POLLRDBAND, Name: "POLLRDBAND"},
+	{Flag: linux.POLLWRNORM, Name: "POLLWRNORM"},
+	{Flag: linux.POLLWRBAND, Name: "POLLWRBAND"},
+	{Flag: linux.POLLMSG, Name: "POLLMSG"},
+	{Flag: linux.POLLREMOVE, Name: "POLLREMOVE"},
+	{Flag: linux.POLLRDHUP, Name: "POLLRDHUP"},
+	{Flag: linux.POLLFREE, Name: "POLLFREE"},
+	{Flag: linux.POLL_BUSY_LOOP, Name: "POLL_BUSY_LOOP"},
+}
+
+func pollFD(t *kernel.Task, pfd *linux.PollFD, post bool) string {
+	revents := "..."
+	if post {
+		revents = PollEventSet.Parse(uint64(pfd.REvents))
+	}
+	return fmt.Sprintf("{FD: %s, Events: %s, REvents: %s}", fd(t, kdefs.FD(pfd.FD)), PollEventSet.Parse(uint64(pfd.Events)), revents)
+}
+
+func pollFDs(t *kernel.Task, addr usermem.Addr, nfds uint, post bool) string {
+	if addr == 0 {
+		return "null"
+	}
+
+	pfds, err := slinux.CopyInPollFDs(t, addr, nfds)
+	if err != nil {
+		return fmt.Sprintf("%#x (error decoding pollfds: %s)", addr, err)
+	}
+
+	s := make([]string, 0, len(pfds))
+	for i := range pfds {
+		s = append(s, pollFD(t, &pfds[i], post))
+	}
+
+	return fmt.Sprintf("%#x [%s]", addr, strings.Join(s, ", "))
+}