Pikachu and Poké Ball
Friday evening is a great time for tinkering with a side project after a long week. You pour some tea, open your laptop and navigate to your project, only to find a red banner across whole app placed by the browser saying “Deceptive site ahead”.
，这一点在服务器推荐中也有详细论述
Each layer catches different attack classes. A namespace escape inside gVisor reaches the Sentry, not the host kernel. A seccomp bypass hits the Sentry’s syscall implementation, which is itself sandboxed. Privilege escalation is blocked by dropping privileges. Persistent state leakage between jobs is prevented by ephemeral tmpfs with atomic unmount cleanup.
Finding these optimization opportunities can itself be a significant undertaking. It requires end-to-end understanding of the spec to identify which behaviors are observable and which can safely be elided. Even then, whether a given optimization is actually spec-compliant is often unclear. Implementers must make judgment calls about which semantics they can relax without breaking compatibility. This puts enormous pressure on runtime teams to become spec experts just to achieve acceptable performance.