From f8b18593198cf7ca1adfca19d846e66080b07942 Mon Sep 17 00:00:00 2001 From: Adin Scannell Date: Thu, 10 Oct 2019 12:45:34 -0700 Subject: 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 --- pkg/sentry/kernel/signalfd/signalfd.go | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'pkg/sentry') 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. -- cgit v1.2.3