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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 linux
import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/hostarch"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/kernel/epoll"
"gvisor.dev/gvisor/pkg/sentry/syscalls"
"gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/waiter"
)
// LINT.IfChange
// EpollCreate1 implements the epoll_create1(2) linux syscall.
func EpollCreate1(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
flags := args[0].Int()
if flags & ^linux.EPOLL_CLOEXEC != 0 {
return 0, nil, syserror.EINVAL
}
closeOnExec := flags&linux.EPOLL_CLOEXEC != 0
fd, err := syscalls.CreateEpoll(t, closeOnExec)
if err != nil {
return 0, nil, err
}
return uintptr(fd), nil, nil
}
// EpollCreate implements the epoll_create(2) linux syscall.
func EpollCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
size := args[0].Int()
if size <= 0 {
return 0, nil, syserror.EINVAL
}
fd, err := syscalls.CreateEpoll(t, false)
if err != nil {
return 0, nil, err
}
return uintptr(fd), nil, nil
}
// EpollCtl implements the epoll_ctl(2) linux syscall.
func EpollCtl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
epfd := args[0].Int()
op := args[1].Int()
fd := args[2].Int()
eventAddr := args[3].Pointer()
// Capture the event state if needed.
flags := epoll.EntryFlags(0)
mask := waiter.EventMask(0)
var data [2]int32
if op != linux.EPOLL_CTL_DEL {
var e linux.EpollEvent
if _, err := e.CopyIn(t, eventAddr); err != nil {
return 0, nil, err
}
if e.Events&linux.EPOLLONESHOT != 0 {
flags |= epoll.OneShot
}
if e.Events&linux.EPOLLET != 0 {
flags |= epoll.EdgeTriggered
}
mask = waiter.EventMaskFromLinux(e.Events)
data = e.Data
}
// Perform the requested operations.
switch op {
case linux.EPOLL_CTL_ADD:
// See fs/eventpoll.c.
mask |= waiter.EventHUp | waiter.EventErr
return 0, nil, syscalls.AddEpoll(t, epfd, fd, flags, mask, data)
case linux.EPOLL_CTL_DEL:
return 0, nil, syscalls.RemoveEpoll(t, epfd, fd)
case linux.EPOLL_CTL_MOD:
// Same as EPOLL_CTL_ADD.
mask |= waiter.EventHUp | waiter.EventErr
return 0, nil, syscalls.UpdateEpoll(t, epfd, fd, flags, mask, data)
default:
return 0, nil, syserror.EINVAL
}
}
func waitEpoll(t *kernel.Task, fd int32, eventsAddr hostarch.Addr, max int, timeoutInNanos int64) (uintptr, *kernel.SyscallControl, error) {
r, err := syscalls.WaitEpoll(t, fd, max, timeoutInNanos)
if err != nil {
return 0, nil, syserror.ConvertIntr(err, syserror.EINTR)
}
if len(r) != 0 {
if _, err := linux.CopyEpollEventSliceOut(t, eventsAddr, r); err != nil {
return 0, nil, err
}
}
return uintptr(len(r)), nil, nil
}
// EpollWait implements the epoll_wait(2) linux syscall.
func EpollWait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
epfd := args[0].Int()
eventsAddr := args[1].Pointer()
maxEvents := int(args[2].Int())
// Convert milliseconds to nanoseconds.
timeoutInNanos := int64(args[3].Int()) * 1000000
return waitEpoll(t, epfd, eventsAddr, maxEvents, timeoutInNanos)
}
// EpollPwait implements the epoll_pwait(2) linux syscall.
func EpollPwait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
maskAddr := args[4].Pointer()
maskSize := uint(args[5].Uint())
if maskAddr != 0 {
mask, err := CopyInSigSet(t, maskAddr, maskSize)
if err != nil {
return 0, nil, err
}
oldmask := t.SignalMask()
t.SetSignalMask(mask)
t.SetSavedSignalMask(oldmask)
}
return EpollWait(t, args)
}
// EpollPwait2 implements the epoll_pwait(2) linux syscall.
func EpollPwait2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
epfd := args[0].Int()
eventsAddr := args[1].Pointer()
maxEvents := int(args[2].Int())
timeoutPtr := args[3].Pointer()
maskAddr := args[4].Pointer()
maskSize := uint(args[5].Uint())
haveTimeout := timeoutPtr != 0
var timeoutInNanos int64 = -1
if haveTimeout {
timeout, err := copyTimespecIn(t, timeoutPtr)
if err != nil {
return 0, nil, err
}
timeoutInNanos = timeout.ToNsec()
}
if maskAddr != 0 {
mask, err := CopyInSigSet(t, maskAddr, maskSize)
if err != nil {
return 0, nil, err
}
oldmask := t.SignalMask()
t.SetSignalMask(mask)
t.SetSavedSignalMask(oldmask)
}
return waitEpoll(t, epfd, eventsAddr, maxEvents, timeoutInNanos)
}
// LINT.ThenChange(vfs2/epoll.go)
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