驱动程序中lsmod命令实际读取的是/proc/modules文件即与lsmod命令对应的结果是cat /proc/modules内核中已经加载的模块的信息存在于/sys/module目录下modprobe命令比insmod命令要强大，它在加载某模块时会同时加载该模块所依赖的其他模块使用modprobe -r filename的方式卸载将同时其依赖的模块modinfo模块名命令可以获得模块的信息modinfo hello.ko

filename:       hello.ko

alias:          a simplest module

description:    A simple Hello World Module

author:         Jimmy

license:        Dual BSD/GPL

srcversion:     FC20E540C350C6F733C7546

depends:

vermagic:       2.6.28-15-generic

SMP mod_unload modversions 586驱动模块参数,MODULE_PARM_DESC可以注解参数如：static int num = 4000;

module_param(num, int,

S_IRUGO);

MODULE_PARM_DESC(myshort,

"A integer");

#include #include MODULE_LICENSE("Dual BSD/GPL");

static char *book_name = "dissecting Linux Device Driver";

static int num = 4000;

static int param[8] = {1, 2, 3, 4, 5, 6, 7, 8};

static int param_len = 8;

static int book_init(void)

{

int i;

printk(KERN_ALERT " book

name: %s\n", book_name);

printk(KERN_ALERT " book

num: %d\n", num);

for(i = 0; i < 8; i++)

{

printk(KERN_ALERT

"param[%d] =  %d \n", i, param[i]);

}

return 0;

}

static void book_exit(void)

{

printk(KERN_ALERT " Book

module exit\n");

}

module_init(book_init);

module_exit(book_exit);

module_param(num, int, S_IRUGO);

module_param(book_name, charp, S_IRUGO);

module_param_array(param, int, &param_len, S_IRUGO);

MODULE_AUTHOR("Jimmy, fightingjimmy@gmail.com");

MODULE_DESCRIPTION("A simple Module for testing module params");

MODULE_VERSION("v1.0");

sudo insmod book.ko

dmesg｜tail -10

[14047.901352]  book name: dissecting Linux Device Driver

[14047.901366]  book num: 4000

[14047.901377] param[0] =  1

[14047.901386] param[1] =  2

[14047.901388] param[2] =  3

[14047.901389] param[3] =  4

[14047.901390] param[4] =  5

[14047.901391] param[5] =  6

[14047.901392] param[6] =  7

[14047.901393] param[7] =  8

sudo rmmod book.ko

sudo insmod book.ko book_name='Hello' num=1000 param=8,7,6,5

[14298.942521]  book name: Hello

[14298.942535]  book num: 1000

[14298.942547] param[0] =  8

[14298.942558] param[1] =  7

[14298.942559] param[2] =  6

[14298.942560] param[3] =  5

[14298.942561] param[4] =  5

[14298.942562] param[5] =  6

[14298.942564] param[6] =  7

[14298.942565] param[7] =  8

sudo rmmod book.ko

sudo insmod book.ko book_name="Hello World" num=1000 param=8,7,6,5

insmod: error inserting 'book.ko': -1 Unknown symbol in module

dmesg｜tail -10

[15097.587159] book: Unknown parameter `world'猜想：可能是因为传入的字符串参数带有空格的原因(有遇到类似情况的请不吝赐教)

linux2.6的/proc/kallsyms文件对应着内核符号表，它记录了以及符号所在的内存地址。EXPORT_SYMBOL(符号名);

EXPROT_SYMBOL_GPL(符号名);

module/

include/

print.h

print/

print.c

Makefile

symbol/

test.c

Makefile

/****************************************

* print.h                               *

*****************************************/

#ifndef PRINT_H

#define PRINT_H

void add_integer(int a, int b);

void sub_integer(int a, int b);

#endif

/****************************************

* print.c                               *

*****************************************/

#include #include #include "print.h"

MODULE_LICENSE("Dual BSD/GPL");

void add_integer(int a, int b)

{

printk(KERN_ALERT " sum:

%d\n", a + b);

}

void sub_integer(int a, int b)

{

printk(KERN_ALERT " sub:

%d\n", a - b);

}

EXPORT_SYMBOL(add_integer);

EXPORT_SYMBOL(sub_integer);

/****************************************

* test.c                                *

*****************************************/

#include #include #include "print.h"

MODULE_LICENSE("GPL");

static int symbol_init(void)

{

printk(KERN_ALERT " Symbol

test init\n");

add_integer(10, 6);

sub_integer(10, 6);

return 0;

}

static void symbol_exit(void)

{

printk(KERN_ALERT " Symbol

test exit\n");

}

module_init(symbol_init);

module_exit(symbol_exit);

print目录下的Makefile：obj-m := print.o

KERNELDIR ?= /lib/modules/$(shell uname -r)/build

PWD := $(shell pwd)

PRINT_INC = $(obj)/../include＃包含print.h头文件EXTRA_CFLAGS += -I $(PRINT_INC)

modules:

$(MAKE) -C $(KERNELDIR)

M=$(PWD) modules

modules_install:

$(MAKE) -C $(KERNELDIR)

M=$(PWD) modules_install

clean:

rm -rf *.o *~ core .depend

.*.cmd *.ko *.mod.c .tmp_versions

.PHONY: modules modules_install clean

symbol目录下的Makefile：obj-m := test.o

KERNELDIR ?= /lib/modules/$(shell uname -r)/build

PWD := $(shell pwd)

SYMBOL_INC = $(obj)/../include

EXTRA_CFLAGS += -I $(SYMBOL_INC)

KBUILD_EXTRA_SYMBOLS=$(obj)/../print/Module.symvers

modules:

$(MAKE) -C $(KERNELDIR)

M=$(PWD) modules

modules_install:

$(MAKE) -C $(KERNELDIR)

M=$(PWD) modules_install

clean:

rm -rf *.o *~ core .depend

.*.cmd *.ko *.mod.c .tmp_versions

.PHONY: modules modules_install clean注意：若是Makefile文件中没有KBUILD_EXTRA_SYMBOLS=$(obj)/../print/Module.symvers则需要将print目录下的Module.symvers拷贝到symbol目录下，这是linux kernel 2.6.26 之后版本的bug (详细描述, 请看)