https://www.kernel.org/doc/html/latest/kbuild/llvm.html

> The Linux kernel has always traditionally been compiled with GNU toolchains such as GCC and binutils. Ongoing work has allowed for Clang and LLVM utilities to be used as viable substitutes. Distributions such as Android, ChromeOS, OpenMandriva, and Chimera Linux use Clang built kernels. Google’s and Meta’s datacenter fleets also run kernels built with Clang.