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// 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/fsimpl/eventfd"
"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
}
vfsObj := t.Kernel().VFS()
fileFlags := uint32(linux.O_RDWR)
if flags&linux.EFD_NONBLOCK != 0 {
fileFlags |= linux.O_NONBLOCK
}
semMode := flags&linux.EFD_SEMAPHORE != 0
eventfd, err := eventfd.New(vfsObj, 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)
}
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