Exploring Pointer-Free Data Exchange in Sentry

When diving into Sentry-micro-kernel concepts, one design choice really stood out: no pointer passing between user space and kernel space.
Instead of relying on pointers, Sentry uses a dedicated buffer called svc_exchange to transfer data between applications and the kernel.
This simple but powerful approach:
🔒 Strengthens security (no unsafe pointer dereferencing)
📐 Simplifies formal verification
⚡ Keeps the kernel lightweight and predictable

Here is how this pointer-free exchange model works, its strengths, limitations, and what it means for developers.
👉 Key takeaway: sometimes removing a feature (pointers) is the best way to reduce complexity and improve system robustness. This is a key design being a balance between security, simplicity, and performance in kernel–user communication