diff options
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_time.go | 139 |
1 files changed, 71 insertions, 68 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_time.go b/pkg/sentry/syscalls/linux/sys_time.go index 4adc8b8a4..134b66dac 100644 --- a/pkg/sentry/syscalls/linux/sys_time.go +++ b/pkg/sentry/syscalls/linux/sys_time.go @@ -175,73 +175,6 @@ func Time(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallC return uintptr(r), nil, nil } -// clockNanosleepRestartBlock encapsulates the state required to restart -// clock_nanosleep(2) via restart_syscall(2). -// -// +stateify savable -type clockNanosleepRestartBlock struct { - c ktime.Clock - end ktime.Time - rem hostarch.Addr -} - -// Restart implements kernel.SyscallRestartBlock.Restart. -func (n *clockNanosleepRestartBlock) Restart(t *kernel.Task) (uintptr, error) { - return 0, clockNanosleepUntil(t, n.c, n.end, n.rem, true) -} - -// clockNanosleepUntil blocks until a specified time. -// -// If blocking is interrupted, the syscall is restarted with the original -// arguments. -func clockNanosleepUntil(t *kernel.Task, c ktime.Clock, end ktime.Time, rem hostarch.Addr, needRestartBlock bool) error { - notifier, tchan := ktime.NewChannelNotifier() - timer := ktime.NewTimer(c, notifier) - - // Turn on the timer. - timer.Swap(ktime.Setting{ - Period: 0, - Enabled: true, - Next: end, - }) - - err := t.BlockWithTimer(nil, tchan) - - timer.Destroy() - - switch { - case linuxerr.Equals(linuxerr.ETIMEDOUT, err): - // Slept for entire timeout. - return nil - case err == linuxerr.ErrInterrupted: - // Interrupted. - remaining := end.Sub(c.Now()) - if remaining <= 0 { - return nil - } - - // Copy out remaining time. - if rem != 0 { - timeleft := linux.NsecToTimespec(remaining.Nanoseconds()) - if err := copyTimespecOut(t, rem, &timeleft); err != nil { - return err - } - } - if needRestartBlock { - // Arrange for a restart with the remaining duration. - t.SetSyscallRestartBlock(&clockNanosleepRestartBlock{ - c: c, - end: end, - rem: rem, - }) - return linuxerr.ERESTART_RESTARTBLOCK - } - return linuxerr.ERESTARTNOHAND - default: - panic(fmt.Sprintf("Impossible BlockWithTimer error %v", err)) - } -} - // Nanosleep implements linux syscall Nanosleep(2). func Nanosleep(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { addr := args[0].Pointer() @@ -279,10 +212,12 @@ func ClockNanosleep(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne return 0, nil, linuxerr.EINVAL } - // Only allow clock constants also allowed by Linux. + // Only allow clock constants also allowed by Linux. (CLOCK_TAI is + // unimplemented.) if clockID > 0 { if clockID != linux.CLOCK_REALTIME && clockID != linux.CLOCK_MONOTONIC && + clockID != linux.CLOCK_BOOTTIME && clockID != linux.CLOCK_PROCESS_CPUTIME_ID { return 0, nil, linuxerr.EINVAL } @@ -301,6 +236,74 @@ func ClockNanosleep(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne return 0, nil, clockNanosleepUntil(t, c, c.Now().Add(dur), rem, true) } +// clockNanosleepUntil blocks until a specified time. +// +// If blocking is interrupted, the syscall is restarted with the original +// arguments. +func clockNanosleepUntil(t *kernel.Task, c ktime.Clock, end ktime.Time, rem hostarch.Addr, needRestartBlock bool) error { + var err error + if c == t.Kernel().MonotonicClock() { + err = t.BlockWithDeadline(nil, true, end) + } else { + notifier, tchan := ktime.NewChannelNotifier() + timer := ktime.NewTimer(c, notifier) + timer.Swap(ktime.Setting{ + Period: 0, + Enabled: true, + Next: end, + }) + err = t.BlockWithTimer(nil, tchan) + timer.Destroy() + } + + switch { + case linuxerr.Equals(linuxerr.ETIMEDOUT, err): + // Slept for entire timeout. + return nil + case err == linuxerr.ErrInterrupted: + // Interrupted. + remaining := end.Sub(c.Now()) + if remaining <= 0 { + return nil + } + + // Copy out remaining time. + if rem != 0 { + timeleft := linux.NsecToTimespec(remaining.Nanoseconds()) + if err := copyTimespecOut(t, rem, &timeleft); err != nil { + return err + } + } + if needRestartBlock { + // Arrange for a restart with the remaining duration. + t.SetSyscallRestartBlock(&clockNanosleepRestartBlock{ + c: c, + end: end, + rem: rem, + }) + return linuxerr.ERESTART_RESTARTBLOCK + } + return linuxerr.ERESTARTNOHAND + default: + panic(fmt.Sprintf("Impossible BlockWithTimer error %v", err)) + } +} + +// clockNanosleepRestartBlock encapsulates the state required to restart +// clock_nanosleep(2) via restart_syscall(2). +// +// +stateify savable +type clockNanosleepRestartBlock struct { + c ktime.Clock + end ktime.Time + rem hostarch.Addr +} + +// Restart implements kernel.SyscallRestartBlock.Restart. +func (n *clockNanosleepRestartBlock) Restart(t *kernel.Task) (uintptr, error) { + return 0, clockNanosleepUntil(t, n.c, n.end, n.rem, true) +} + // Gettimeofday implements linux syscall gettimeofday(2). func Gettimeofday(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { tv := args[0].Pointer() |