C语言程序介绍

C语言程序介绍代码分为：makefile，内核态程序globalmem.c用户态程序user.c功能是把一个数组排序，你也可以使用readwrite函数往内存里写东西。运行方法：make，产生globalmem.ko文件，Insmodglobalmem.ko,看一下dmesg-c是否有提示信息(也可以lsmod|grep"glo")，有的话说明加载上了，然后mknod/devglobalmemc2540，看一下ls/proc/device/|grep"glo"有东西没。然后运行用户态程序，数组被排序了。dmesg-c可以看到提示信息，在模块中排序了。上代码(是带锁的代码，顺便练练手)makefile1#makefileforkernel2.62ifneq($(KERNELRELEASE),)3#mymodule-objs:=file1.ofile2.o4obj-m:=globalmem.o6else7PWD:=$(shellpwd)8KVER:=$(shelluname-r)9KDIR:=/lib/modules/$(KVER)/build10all:11$(MAKE)-C$(KDIR)M=$(PWD)12clean:13rm-rf.*.cmd*.o*.mod.c*.ko.tmp_versions1415endif16内核模块1#include2#include3#include4#include5#include6#include7#include8#include9#include10#include11#include"mem.h"1213#defineGLOBALMEM_SIZE0x100014#defineMEM_CLEAR0x115#defineARRAY_INSTER0x216#defineGLOBALMEM_MAJOR25418staticintglobalmem_major=GLOBALMEM_MAJOR;1920//thestructofglobal21typedefstructglobalmem_dev{22structcdevcdev;23unsignedcharmem[GLOBALMEM_SIZE];24//addlock,signalstructsemaphoresem;atomic_tato;27}globalmem_dev;29globalmem_dev*global;31typedefstructarithmetic_st{32intbuf[10];33intlen;34}arithmetic_st;39intglobalmem_open(structinode*inode,structfile*filp)40{filp->private_data=global;//youcanonlyopenonefileif(!atomic_dec_and_test(&global->ato))44{45printk(KERN_NOTICE"atomicislock");46return-EBUSY;47}48return0;49}51intglobalmem_release(structinode*inode,structfile*filp)52{atomic_inc(&global->ato);return0;55}58//read59staticssize_tglobalmem_read(structfile*filp,charuser*buf,size_t