the code below is incomplete.. but the scala is in that way.
#define MODULE
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/sem.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/irq.h>
typedef struct Dev {
void **data;
struct semaphore sem;
struct Dev *next;
int quantum;
int qset;
unsigned long size;
unsigned int access_key;
} Dev;
loff_t skull_seek(struct file *, loff_t, int);
ssize_t skull_read(struct file *, char *, size_t, loff_t *);
ssize_t skull_write(struct file *, const char *, size_t, loff_t *);
int skull_ioctl(struct inode *, struct file *, unsigned int, unsigned
long);
int skull_open(struct inode *, struct file *);
int skull_release(struct inode *, struct file *);
struct file_operations f_ops = {
llseek: skull_seek,
read: skull_read,
write: skull_write,
ioctl: skull_ioctl,
open: skull_open,
release: skull_release,
};
unsigned long skull_major = 254;
int result;
init_module(void)
{
result = register_chrdev(skull_major, "skull", &f_ops);
if(skull_major == 0) skull_major = result;
if(result < 0) return result;
printk("Ok\n");
return 0;
}
cleanup_module(void)
{
unregister_chrdev(skull_major, "skull");
printk("stmodule is removed\n");
}
loff_t skull_seek(struct file * filp, loff_t lale, int inte)
{
return 0;
}
ssize_t skull_read(struct file * filp, char *ch, size_t boyut, loff_t
*bil)
{
return 0;
}
ssize_t skull_write(struct file * fp, const char *ch, size_t byt, loff_t
*bil)
{
return 0;
}
int skull_ioctl(struct inode * inodi, struct file * filp, unsigned
int uint, unsigned long unlong )
{
return 0;
}
int skull_open(struct inode * inode, struct file * filp)
{
int i;
loff_t *bil;
Dev *dev;
const char *buf;
printk("Major Number =>%d\n",inode->i_rdev >> 8);
printk("Minor Number =>%d\n",inode->i_rdev & 0xff);
filp->f_op = &f_ops;
sema_init(&dev->sem, 1);
dev = (Dev *)filp->private_data;
/* the problem is below */
if((filp->f_flags & O_ACCMODE) == O_WRONLY) {
down_interruptible(&dev->sem);
up(&dev->sem);
}
MOD_INC_USE_COUNT;
return 0;
}
int skull_release(struct inode * inode, struct file * filp)
{
MOD_DEC_USE_COUNT;
return 0;
}
i compile this code with gcc -c -D__MODULE__ -D__KERNEL__ scull.c
there in no problem when reading the device with the major number assigned
to this
module. like this cat /dev/scull0
however, when trying to write to the device such as using
cat > /dev/scull0
then, kernel fails and halts. there is an opps..
according to you.. what is the problem?
and how can i overcome the GPL warnings when i install the module.. i dont
wanna see the warnings. how should i make changes in the code not to let
the warning outcome..
sincerely
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