FC3 module sys_print how...

["Mukund JB." <mukundjb@esntechnologies.co.in>]

Dear Linux-lovers.

 

I am trying to build a 2.6.10 linux kernel module to print messages to a
file. I have done this 2.4 and I was successful but I am failing here.

 

I am using the sys_open, sys_write calls to do so.

I am getting a compilation warning and I find no .ko file created
finally instead I find an .o.ko file.

 

*** WARNIG: "sys_write" [/home/cf.o.ko] undefined!

Below is the module code. Please suggest me what could be the problem:-

 

 

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <asm/fcntl.h>        /* for O_WRONLY */

#include <linux/syscalls.h>   /* for sys_ functions */

#include <asm/uaccess.h>      /* for set_fs(), get_fs() etc. */

#include <linux/string.h>     /* for string length */

#include <linux/slab.h>       /* for kmalloc */

 

MODULE_LICENSE("GPL");

/*

#define DBG

#define PRINTK(fmt,arg...) printk("DBG INFO <%s> | "
fmt,__FUNCTION__,##arg)

#else

#define PRINTK(fmt,arg...) while(0)

#endif

*/

 

typedef struct tagWRITE_TEST

{

      unsigned long fd;

      unsigned long x;

      

}WRITE_TEST, *PWRITE_TEST;

 

PWRITE_TEST ptest;

 

void SysPrint(char * pString, ...)

{

      static char buff[1024];

      va_list ap;

 

      va_start(ap,pString);

      vsprintf((char *)buff, pString, ap);

      va_end(ap);

      

      sys_write(ptest->fd,(char *)buff,(size_t)strlen(buff));

}

 

int init_module(void)

{

      

      printk("<%s> invoked!\n",__FUNCTION__);

      printk("File Creation Testing in Kernel Module!\n");

 

      set_fs(get_ds());

      

      /* allocate the memory for structre */

      ptest = (PWRITE_TEST)kmalloc(sizeof(WRITE_TEST),GFP_KERNEL);

      if(ptest == NULL)

      {

            printk("Structure Memory Allocation Fails!\n");

            return -ENOMEM;

      }

      

      ptest->fd = sys_open("srcdebug.txt", O_CREAT | O_WRONLY, 644);

      if (ptest->fd == 0)

      {

            SysPrint("File Creation Error!!!\n");

            return 1;

      }

      

      SysPrint("File Creation Testing in Kernel Module!\n");

      SysPrint("Srinivas Testing the File Creation\n");

      sys_close(ptest->fd);

      

      return 0;

}

 

void cleanup_module(void)

{

      printk("Good bye!\n");

 

      /* free the allocated memory */

      kfree(ptest);

}

 

Regards,

Mukund jampala

 


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