Linux drops legacy C Binder driver for Rust rewrite

The Linux kernel is dropping its original C implementation of Binder, the IPC driver Android depends on, in favor of the Rust version that has reached feature parity and production use.

Carlos Llamas of Google proposed removing the legacy driver, citing more than 15 years of growing complexity that made routine changes painful and left the code prone to security bugs. Alice Ryhl led the Rust rewrite over the past couple of years. According to Llamas, that work not only matched the old driver's features but often beat its performance, and the Rust Binder has already run successfully on Android devices long enough that it can no longer be treated as an experiment.

Binder sits at the center of Android's process model, so the switch is more than a language swap. With the C code gone, new features and optimizations will land only on the Rust path, concentrating maintenance where memory-safety guarantees are stronger and the surface for the kinds of defects that dogged the old driver is smaller.

Llamas wrote that it was time to move on and focus development entirely on the Rust driver. Ryhl acked the change.