Merge release-20200422.0-25-gda71dc7 (automated)

1 files changed, 59 insertions, 0 deletions

diff --git a/pkg/sentry/syscalls/linux/vfs2/eventfd.go b/pkg/sentry/syscalls/linux/vfs2/eventfd.go
new file mode 100755
index 000000000..bd2194972
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/eventfd.go
@@ -0,0 +1,59 @@
+// Copyright 2018 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 vfs2
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Eventfd2 implements linux syscall eventfd2(2).
+func Eventfd2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	initVal := uint64(args[0].Uint())
+	flags := uint(args[1].Uint())
+	allOps := uint(linux.EFD_SEMAPHORE | linux.EFD_NONBLOCK | linux.EFD_CLOEXEC)
+
+	if flags & ^allOps != 0 {
+		return 0, nil, syserror.EINVAL
+	}
+
+	fileFlags := uint32(linux.O_RDWR)
+	if flags&linux.EFD_NONBLOCK != 0 {
+		fileFlags |= linux.O_NONBLOCK
+	}
+	semMode := flags&linux.EFD_SEMAPHORE != 0
+	eventfd, err := t.Kernel().VFS().NewEventFD(initVal, semMode, fileFlags)
+	if err != nil {
+		return 0, nil, err
+	}
+	defer eventfd.DecRef()
+
+	fd, err := t.NewFDFromVFS2(0, eventfd, kernel.FDFlags{
+		CloseOnExec: flags&linux.EFD_CLOEXEC != 0,
+	})
+	if err != nil {
+		return 0, nil, err
+	}
+
+	return uintptr(fd), nil, nil
+}
+
+// Eventfd implements linux syscall eventfd(2).
+func Eventfd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	args[1].Value = 0
+	return Eventfd2(t, args)
+}