Vortrag:Howto Linux-Kernel
TODO
HOWTO Linux Kernel
Meta
Datum: 20.11.08 20:00 Uhr Referent: Georg / gnu
Code
Makefile
obj-m += minDev.o
obj-m += halloKernel.o
obj-m += bad.o
all:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
bad.c
- include <linux/module.h>
- include <linux/mm.h>
int init_module ( void )
{
int* badarray, *funcptr;
int i;
printk ("Bad Kernel Module\n");
badarray = (int*) kmalloc(100, GFP_KERNEL);
if(!badarray) {
printk(KERN_WARNING "no more memory :(\n");
return 0;
}
funcptr = (int*) &do_gettimeofday;
printk("0x%08x do_gettimeofday\n", (int)funcptr);
/*
badarray = funcptr
for(i=0; i<500; ++i) badarray[i] = 0xfea1dead;
*/
kfree(badarray);
return 0;
}
void cleanup_module( void )
{
printk ("Goodbye Kernel.\n");
}
MODULE_AUTHOR("gnu");
MODULE_LICENSE("GPL");
halloKernel.c
- include <linux/module.h>
int init_module ( void )
{
printk ("Hello Kernel!\n");
return 0;
}
void cleanup_module( void )
{
printk ("Goodbye Kernel.\n");
}
MODULE_AUTHOR("gun");
MODULE_LICENSE("GPL");
minDev.c
- include <linux/module.h>
- include <linux/fs.h>
static int device_open(struct inode *inp, struct file *filp)
{
return 0;
}
static ssize_t device_read(struct file *filp, char *buf, size_t length, loff_t *f_pos)
{
return 0;
}
static ssize_t device_write(struct file *filp, const char *buf, size_t length, loff_t *f_pos)
{
printk( "received: %c%c\n",buf[0], buf[1]);
return 2;
}
static int device_release(struct inode *inp, struct file *filp)
{
return 0;
}
static struct file_operations fops = {
open: device_open,
read: device_read,
write: device_write,
release: device_release
};
//////////////////////////////////////////////////////////////
static int MajorNumber = 0;
int init_module ( void )
{
printk ("mindev loaded!\n");
MajorNumber = register_chrdev(0, "mydevice", &fops);
if( MajorNumber < 0 )
{
printk ("Registering mydevice failed.\n");
return MajorNumber;
}
else
{
printk ("create a device: 'mknod /dev/mydevice c %d 0'.\n",MajorNumber);
}
return 0;
}
void cleanup_module( void )
{
unregister_chrdev(MajorNumber, "mydevice");
printk ("mindev unloaded.\n");
}
MODULE_AUTHOR("gnu");
MODULE_LICENSE("GPL");
Links zum Workshop
* Alle Links von http://www.linuxhq.com/lkprogram.html * Handbuch zur Linux Kernel-Entwicklung (organisatorisches) http://ldn.linuxfoundation.org/book/how-participate-linux-community
