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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/errors/linuxerr"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/fsimpl/timerfd"
"gvisor.dev/gvisor/pkg/sentry/kernel"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
)
// TimerfdCreate implements Linux syscall timerfd_create(2).
func TimerfdCreate(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
clockID := args[0].Int()
flags := args[1].Int()
if flags&^(linux.TFD_CLOEXEC|linux.TFD_NONBLOCK) != 0 {
return 0, nil, linuxerr.EINVAL
}
// Timerfds aren't writable per se (their implementation of Write just
// returns EINVAL), but they are "opened for writing", which is necessary
// to actually reach said implementation of Write.
fileFlags := uint32(linux.O_RDWR)
if flags&linux.TFD_NONBLOCK != 0 {
fileFlags |= linux.O_NONBLOCK
}
var clock ktime.Clock
switch clockID {
case linux.CLOCK_REALTIME:
clock = t.Kernel().RealtimeClock()
case linux.CLOCK_MONOTONIC, linux.CLOCK_BOOTTIME:
clock = t.Kernel().MonotonicClock()
default:
return 0, nil, linuxerr.EINVAL
}
vfsObj := t.Kernel().VFS()
file, err := timerfd.New(t, vfsObj, clock, fileFlags)
if err != nil {
return 0, nil, err
}
defer file.DecRef(t)
fd, err := t.NewFDFrom(0, file, kernel.FDFlags{
CloseOnExec: flags&linux.TFD_CLOEXEC != 0,
})
if err != nil {
return 0, nil, err
}
return uintptr(fd), nil, nil
}
// TimerfdSettime implements Linux syscall timerfd_settime(2).
func TimerfdSettime(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
fd := args[0].Int()
flags := args[1].Int()
newValAddr := args[2].Pointer()
oldValAddr := args[3].Pointer()
if flags&^(linux.TFD_TIMER_ABSTIME) != 0 {
return 0, nil, linuxerr.EINVAL
}
file := t.GetFile(fd)
if file == nil {
return 0, nil, linuxerr.EBADF
}
defer file.DecRef(t)
tfd, ok := file.Impl().(*timerfd.TimerFileDescription)
if !ok {
return 0, nil, linuxerr.EINVAL
}
var newVal linux.Itimerspec
if _, err := newVal.CopyIn(t, newValAddr); err != nil {
return 0, nil, err
}
newS, err := ktime.SettingFromItimerspec(newVal, flags&linux.TFD_TIMER_ABSTIME != 0, tfd.Clock())
if err != nil {
return 0, nil, err
}
tm, oldS := tfd.SetTime(newS)
if oldValAddr != 0 {
oldVal := ktime.ItimerspecFromSetting(tm, oldS)
if _, err := oldVal.CopyOut(t, oldValAddr); err != nil {
return 0, nil, err
}
}
return 0, nil, nil
}
// TimerfdGettime implements Linux syscall timerfd_gettime(2).
func TimerfdGettime(t *kernel.Task, sysno uintptr, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
fd := args[0].Int()
curValAddr := args[1].Pointer()
file := t.GetFile(fd)
if file == nil {
return 0, nil, linuxerr.EBADF
}
defer file.DecRef(t)
tfd, ok := file.Impl().(*timerfd.TimerFileDescription)
if !ok {
return 0, nil, linuxerr.EINVAL
}
tm, s := tfd.GetTime()
curVal := ktime.ItimerspecFromSetting(tm, s)
_, err := curVal.CopyOut(t, curValAddr)
return 0, nil, err
}
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