A put option is a contract that gives its owner the right to sell an asset at a future date at a predetermined price.
Instead of filtering syscalls to the host kernel, gVisor interposes a completely separate kernel implementation called the Sentry between the untrusted code and the host. The Sentry does not access the host filesystem directly; instead, a separate process called the Gofer handles file operations on the Sentry’s behalf, communicating over a restricted protocol. This means even the Sentry’s own file access is mediated.
。关于这个话题，服务器推荐提供了深入分析
Филолог заявил о массовой отмене обращения на «вы» с большой буквы09:36
Bats in Churches