On Sun, Sep 15, 2024 at 10:58 PM Hari Bathini <hbathini@xxxxxxxxxxxxx> wrote: > > + > + /* > + * Generated stack layout: > + * > + * func prev back chain [ back chain ] > + * [ ] > + * bpf prog redzone/tailcallcnt [ ... ] 64 bytes (64-bit powerpc) > + * [ ] -- ... > + > + /* Dummy frame size for proper unwind - includes 64-bytes red zone for 64-bit powerpc */ > + bpf_dummy_frame_size = STACK_FRAME_MIN_SIZE + 64; What is the goal of such a large "red zone" ? The kernel stack is a limited resource. Why reserve 64 bytes ? tail call cnt can probably be optional as well.