FUNCTION_DESCR_SIZE
alloclen = proglen + FUNCTION_DESCR_SIZE + fixup_len + extable_len;
fp->aux->extable = (void *)fimage + FUNCTION_DESCR_SIZE + proglen + fixup_len;
code_base = (u32 *)(image + FUNCTION_DESCR_SIZE);
fcode_base = (u32 *)(fimage + FUNCTION_DESCR_SIZE);
fp->jited_len = cgctx.idx * 4 + FUNCTION_DESCR_SIZE;
FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size));