what`s wrong?

il boba (il_boba@hotmail.com)
Wed, 24 Apr 2002 18:06:42 +0200


Is there anybody that can help me understand what`s wrong with this code?

Mostly i`m not sure about the correct use of the functions filp_open,
generic_file_read and filp_close.

When i compile as a module on the kernel and after, when i do the INSMOD ,
at first said SEGMENTATION FAULT, right now it just blocks the whole
machine.

Any help or hint is very welcome!!!
thanks
boba

Here is the code:

/* FILE NAME : pops.c */

#include <linux/kernel.h>
#include <linux/module.h>

#define BUFSIZ 8192

#if CONFIG_MODVERSIONS==1
#define MODVERSIONS
#include <linux/modversions.h>
#endif

#include <linux/fs.h>

#if LINUX_VERSION_CODE > KERNEL_VERSION(2,2,0)
#include <asm/uaccess.h>
#endif

int init_err_frame(int []);

/* prints the vector err_frame */

int init_module()
{
int err_frame[BUFSIZ];
int i, k;
k = init_err_frame(err_frame);
for (i = 0; i < k; i++){
printk("%d \n", err_frame[i]);
}
return 0;
}

/* inizializza il vettore err_frame */

int init_err_frame(int err_frame[]) {

int i, k = 0, j = 0;
char buffer[BUFSIZ];
int temp[2];
int retval;

struct file * f =
filp_open("/usr/src/kernel-source-2.2.19/pinux/misc/err_file", 0, 0); /* i
want it only readable */
if (f == '\0'){
printk ("errore nell' APERTURA del file d'errore");
return -1;
}
printk("%d ", f->f_count);
if ((generic_file_read(f, buffer, BUFSIZ, &f->f_pos)) < 0 ){
printk ("errore nella LETTURA del file");
if ((retval = filp_close(f, NULL)) < 0){
printk ("errore nella CHIUSURA del file");
return -3;
}
return -2;
}
for (i=0; i < '\0'; i++){
temp[j] = buffer[i];
if (j == 1){
err_frame[k] = (int) temp[0] + (int) temp[1];
j = 0;
k++;
} else
j = 1;
}
filp_close(f,NULL);
return k;
}

void cleanup_module()
{
printk(".........");
}

and i compile it as
cc -D__KERNEL__ -I/usr/src/kernel-source-2.2.19/include -Wall
-Wstrict-prototypes -O2 -fomit-frame-pointer -fno-strict-aliasing -pipe
-fno-strength-reduce -mpreferred-stack-boundary=2 -m486 -DCPU=486 -DMODULE
-DEXPORT_SYMTAB -c pops.c

_________________________________________________________________
MSN Foto č il modo pių semplice per condividere e stampare le tue foto:
http://photos.msn.com/support/worldwide.aspx

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/