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| author | Adin Scannell <ascannell@google.com> | 2019-10-10 12:45:34 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2019-10-10 12:51:22 -0700 |
| commit | f8b18593198cf7ca1adfca19d846e66080b07942 (patch) | |
| tree | 253ea05b2729fbac2e7ddb25e3030474535ab782 /pkg/sentry/kernel/signalfd | |
| parent | 14952d01fb5fa03a40dbb241b4c12f5a400a3577 (diff) | |
Fix signalfd polling.
The signalfd descriptors otherwise always show as available. This can lead
programs to spin, assuming they are looking to see what signals are pending.
Updates #139
PiperOrigin-RevId: 274017890
Diffstat (limited to 'pkg/sentry/kernel/signalfd')
| -rw-r--r-- | pkg/sentry/kernel/signalfd/signalfd.go | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/pkg/sentry/kernel/signalfd/signalfd.go b/pkg/sentry/kernel/signalfd/signalfd.go index 06fd5ec88..4b08d7d72 100644 --- a/pkg/sentry/kernel/signalfd/signalfd.go +++ b/pkg/sentry/kernel/signalfd/signalfd.go @@ -121,7 +121,10 @@ func (s *SignalOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOS // Readiness implements waiter.Waitable.Readiness. func (s *SignalOperations) Readiness(mask waiter.EventMask) waiter.EventMask { - return mask & waiter.EventIn + if mask&waiter.EventIn != 0 && s.target.PendingSignals()&s.Mask() != 0 { + return waiter.EventIn // Pending signals. + } + return 0 } // EventRegister implements waiter.Waitable.EventRegister. |