On Mon, Feb 21, 2005 at 21:14:03 -0800, linux lover wrote:
> Hello Srinivas,
> I am using RedHat 9 with its kernel
> 2.4.20-8 . When i make your program it compiled
> successfully but i am getting following errors while i
> insmod
> insmod cf.o
> cf.o: unresolved symbol sys_open
> cf.o: unresolved symbol sys_write
RedHat kernel, unfortunately, does not have much in common with Linus'
kernels. In this respect they are right though, the code is bogus and
should not compile.
-------------------------------------------------------------------------------
Jan 'Bulb' Hudec <bulb@xxxxxx>
The (bogus) code follows.
> > cre_fil.c
> >
> ------------------------------------------------------------------
> > #include <linux/kernel.h>
> > #include <linux/module.h>
> > #include <asm/fcntl.h> /* for O_WRONLY */
> > #include <linux/syscall.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");
> >
> > 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,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)
> > {
> > printk("File Creation Error!!!\n");
> > return 1;
> > }
> >
> > SysPrint("File Creation Testing in Kernel
> > Module!\n");
> > SysPrint("Srinivas Testing the File Creation\n");
> >
> > /* close the file here */
> > sys_close(ptest->fd);
> >
> > return 0;
> > }
> >
> > void cleanup_module(void)
> > {
> > printk("Good bye!\n");
> >
> > /* free the allocated memory */
> > kfree(ptest);
> >
> > }
> >
> > Makefile
> > ------------------------------------------------
> > INCDIR=/usr/src/linux-2.4/include
> >
> > CFLAGS=-DMODULE -D__KERNEL__ -I$(INCDIR) -O2 -Wall
> >
> > OBJS=cre_fil.o
> > TARGET=cf.o
> >
> > $(TARGET): $(OBJS)
> > $(LD) -r -o $(TARGET) $(OBJS)
> >
> > clean:
> > $(RM) -f $(TARGET) $(OBJS)
> >
> >
> ------------------------------------------------------------------------
Attachment:
signature.asc
Description: Digital signature
