CreateFakeRootfs creates a fake rootfs for test.

CreateInfraRootfs creates a rootfs similar to CreateFakeRootfs, but only copies a single binary from the host into the rootfs.

ExecCmd executes a command with args and returns its output as a string along with an error, if any.

ExecCmdWithStdStreams execute a command with the specified standard streams.

Prctl is a way to make the prctl linux syscall.

StatusToExitCode converts wait status code to an exit code.