我之前的内核是2.4.20－8， 在该系统下，写了几个驱动程序模块，并且

运行良好；

后来，重新编译内核，使用原系统提供的源代码树，在其下面配置编译内核，

然后进入新内核的系统，发现之前写的模块make报错，然后回到原来的内核的系统，

make 仍然出错，不知道具体是什么原因；

错误代码如下：
-D__KERNEL__ -DMODULE -I/usr/src/linux-2.4.20-8/include -O -Wall -g -c short.c -o short.o
In file included from /usr/src/linux-2.4.20-8/include/linux/config.h:4,
                 from short.c:26:
/usr/include/linux/autoconf.h:1:2: #error Invalid kernel header included in userspace
In file included from /usr/src/linux-2.4.20-8/include/linux/module.h:25,
                 from short.c:27:
/usr/include/asm/atomic.h:40:2: warning: #warning Using kernel header in userland program. BAD!
In file included from /usr/src/linux-2.4.20-8/include/linux/dcache.h:7,
                 from /usr/src/linux-2.4.20-8/include/linux/fs.h:19,
                 from /usr/src/linux-2.4.20-8/include/linux/capability.h:17,
                 from /usr/src/linux-2.4.20-8/include/linux/binfmts.h:4,
                 from /usr/src/linux-2.4.20-8/include/linux/sched.h:10,
                 from short.c:29:
/usr/src/linux-2.4.20-8/include/linux/mount.h: In function `mntget':
/usr/src/linux-2.4.20-8/include/linux/mount.h:37: warning: implicit declaration
of function `atomic_inc'
/usr/src/linux-2.4.20-8/include/linux/mount.h: In function `mntput':
/usr/src/linux-2.4.20-8/include/linux/mount.h:46: warning: implicit declaration
of function `atomic_dec_and_test'
In file included from /usr/src/linux-2.4.20-8/include/linux/fs.h:26,
                 from /usr/src/linux-2.4.20-8/include/linux/capability.h:17,
                 from /usr/src/linux-2.4.20-8/include/linux/binfmts.h:4,
                 from /usr/src/linux-2.4.20-8/include/linux/sched.h:10,
                 from short.c:29:
/usr/include/asm/bitops.h:327:2: warning: #warning This includefile is not available on all architectures.
/usr/include/asm/bitops.h:328:2: warning: #warning Using kernel headers in userspace: atomicity not guaranteed
In file included from /usr/src/linux-2.4.20-8/include/linux/ext3_fs_i.h:19,
                 from /usr/src/linux-2.4.20-8/include/linux/fs.h:298,
                 from /usr/src/linux-2.4.20-8/include/linux/capability.h:17,
                 from /usr/src/linux-2.4.20-8/include/linux/binfmts.h:4,
                 from /usr/src/linux-2.4.20-8/include/linux/sched.h:10,
                 from short.c:29:
/usr/src/linux-2.4.20-8/include/linux/rwsem.h: In function `down_read':
/usr/src/linux-2.4.20-8/include/linux/rwsem.h:46: warning: implicit declaration
of function `__down_read'
/usr/src/linux-2.4.20-8/include/linux/rwsem.h: In function `down_read_trylock':
/usr/src/linux-2.4.20-8/include/linux/rwsem.h:57: warning: implicit declaration
of function `__down_read_trylock'
/usr/src/linux-2.4.20-8/include/linux/rwsem.h: In function `down_write':
/usr/src/linux-2.4.20-8/include/linux/rwsem.h:68: warning: implicit declaration
of function `__down_write'
/usr/src/linux-2.4.20-8/include/linux/rwsem.h: In function `down_write_trylock':/usr/src/linux-2.4.20-8/include/linux/rwsem.h:79: warning: implicit declaration
of function `__down_write_trylock'
/usr/src/linux-2.4.20-8/include/linux/rwsem.h: In function `up_read':
/usr/src/linux-2.4.20-8/include/linux/rwsem.h:90: warning: implicit declaration
of function `__up_read'
/usr/src/linux-2.4.20-8/include/linux/rwsem.h: In function `up_write':
/usr/src/linux-2.4.20-8/include/linux/rwsem.h:100: warning: implicit declaration of function `__up_write'
In file included from /usr/src/linux-2.4.20-8/include/linux/fs.h:298,
                 from /usr/src/linux-2.4.20-8/include/linux/capability.h:17,
                 from /usr/src/linux-2.4.20-8/include/linux/binfmts.h:4,
                 from /usr/src/linux-2.4.20-8/include/linux/sched.h:10,
                 from short.c:29:
/usr/src/linux-2.4.20-8/include/linux/ext3_fs_i.h: At top level:
/usr/src/linux-2.4.20-8/include/linux/ext3_fs_i.h:75: field `truncate_sem' has incomplete type
/usr/src/linux-2.4.20-8/include/linux/ext3_fs_i.h:76: confused by earlier errors, bailing out
make: *** [short.o] Error 1

配置后产生一个配置文件,就是源代码目录下的.config

里面存放了内核配置信息,并且被内核源代码的其它文件包含

但是如果是通过make munuconfig等内核源代码提供的脚本编译,应该不会出错的

1.你在新内核下编译出错,不晓得是什么原因

你可以检查一下,编译内核一般是需要root权限的

2.重新切换回原来的内核,只是运行内核变化了,内核源代码树并没有改变
所以你重新编译原来的模块可以会出错.
你可以把.config删除,然后执行make clean,再重新执行make menuconfig,不需要
配置,产生默认的.config,然后执行 make mrproper,这样就恢复了原来的环境