init_post函数来自同一个文件的814行：
811/* This is a non __init function. Force it to be noinline otherwise gcc
812 * makes it inline to init() and it becomes part of init.text section
813 */
814static noinline int init_post(void)
815 __releases(kernel_lock)
816{
817 /* need to finish all async __init code before freeing the memory */
818 async_synchronize_full();
819 free_initmem();
820 unlock_kernel();
821 mark_rodata_ro();
822 system_state = SYSTEM_RUNNING;
823 numa_default_policy();
824
825
826 current->signal->flags |= SIGNAL_UNKILLABLE;
827
828 if (ramdisk_execute_command) {
829 run_init_process(ramdisk_execute_command);
830 printk(KERN_WARNING "Failed to execute %s/n",
831 ramdisk_execute_command);
832 }
833
834 /*
835 * We try each of these until one succeeds.
836 *
837 * The Bourne shell can be used instead of init if we are
838 * trying to recover a really broken machine.
839 */
840 if (execute_command) {
841 run_init_process(execute_command);
842 printk(KERN_WARNING "Failed to execute %s. Attempting "
843 "defaults.../n", execute_command);
844 }
845 run_init_process("/sbin/init");
846 run_init_process("/etc/init");
847 run_init_process("/bin/init");
848 run_init_process("/bin/sh");
849
850 panic("No init found. Try passing init= option to kernel. "
851 "See Linux Documentation/init.txt for guidance.");
852}
819行，这就是上面说到的那个释放init代码的函数了，它显然不能是__init打头：
void free_initmem(void)
{
free_init_pages("unused kernel memory",
(unsigned long)(&__init_begin),
(unsigned long)(&__init_end));
}
这个函数基本上就是执行init了，失败就panic了。顺便说一句，/dev/console最后被012描述符引用，也就是所有没有reopen的进程的标准输入输出和出错。
到此，内核启动过程就完成了，init根据根文件系统的配置在初始化用户态的进程，启动系统。我们的疯狂内核，也就到此告一段落了。
