Before destroying the Kernel, we disable signal forwarding,
relinquishing control to the Go runtime. External signals that arrive
after disabling forwarding but before the sandbox exits thus may use
runtime.raise (i.e., tkill(2)) and violate the syscall filters.
Adjust forwardSignals to handle signals received after disabling
forwarding the same way they are handled before starting forwarding.
i.e., by implementing the standard Go runtime behavior using tgkill(2)
instead of tkill(2).
This also makes the stop callback block until forwarding actually stops.
This isn't required to avoid tkill(2) but is a saner interface.
PiperOrigin-RevId: 211995946
Change-Id: I3585841644409260eec23435cf65681ad41f5f03
This is to troubleshoot problems with a hung process that is
not responding to 'runsc debug --stack' command.
PiperOrigin-RevId: 210483513
Change-Id: I4377b210b4e51bc8a281ad34fd94f3df13d9187d
We have been unnecessarily creating too many savable types implicitly.
PiperOrigin-RevId: 206334201
Change-Id: Idc5a3a14bfb7ee125c4f2bb2b1c53164e46f29a8
SendExternalSignal is no longer called before CreateProcess, so it can
enforce this simplified precondition.
StartForwarding, and after Kernel.Start.
PiperOrigin-RevId: 201591170
Change-Id: Ib7022ef7895612d7d82a00942ab59fa433c4d6e9
SIGUSR2 was being masked out to be used as a way to dump sentry
stacks. This could cause compatibility problems in cases anyone
uses SIGUSR2 to communicate with the container init process.
PiperOrigin-RevId: 201575374
Change-Id: I312246e828f38ad059139bb45b8addc2ed055d74
Michael Pratt
Fabricio Voznika
Zhaozhong Ni
Googler