parameters passing problem in driver module

From: Srinivas Surabhi (srinivas.surabhi@wipro.com)
Date: Tue Feb 20 2001 - 05:37:55 EST


In application program ,code for call to write system call is given
below...
      #include<fcntl.h>
    main()
         {
          int count,fd;
         fd=open("/dev/pseudo",O_RDWR);
          write(fd,buff,5);
          }
          
In driver module code for getting the buffer and count

    #include<all related header files...>
     
    int psuedo_write(struct inode*in,struct file*fp,char *buf,int count)
    {
      kprintf("<1>pseudo_write routine called \n");
      kprintf("<1>count=%d \n",count);
      kprintf("<1>buffer=%s \n",buff);
      return 0;
    }
/******so here after inserting the module into the kernel using insmod
pseudo.o and executing the application cc -c pseudo_app.c, the o/p on
console is *****/

"pseudo_write routine called"
"count=9988345352" /*garbage*/
"buffer=@#%h" . /*garbage*/
 
/*** but neither the buffer is carried from user space to kernel space nor
the count, why?***/Please help me
out.

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This archive was generated by hypermail 2b29 : Fri Feb 23 2001 - 21:00:21 EST