Hello Friends,
Please help me finding the bug in the following code. When i ran this code the system is
hanging (kernel panic). I am trying to open a file in kernel space and try to read, it is able open
the file but unable to read.
Code is :
##############################
struct file *filp;
mm_segment_t oldfs;
char *fname = "/etc/testfile";
int error = 0;
char *buf = NULL;
int bytesread = 0;
oldfs = get_fs();
set_fs(get_ds());
buf = (char*)kmalloc(50, GFP_ATOMIC);
if( buf == NULL ) {
printk(KERN_DEBUG"[Unable to allocate buf memory]\n");
error = -3;
goto out2;
}
memset(buf,0,50);
filp = filp_open(fname,O_RDONLY,0);
if( IS_ERR(filp) || filp==NULL ) {
printk(KERN_DEBUG"[opening file error:%s]\n",fname);
error = -1;
goto out;
}
if( !filp || !filp->f_op || !filp->f_op->read ) {
printk(KERN_DEBUG"[filp does not have read function]\n");
error = -2;
goto out1;
}
// I am getting error here
bytesread = filp->f_op->read(filp, buf, 41, &filp->f_pos);
buf[bytesread]='\0';
printk(KERN_DEBUG"[buffer-%s]\n",buf);
out1:
if( filp!=NULL || !IS_ERR(filp) )
filp_close(filp,NULL);
out:
if( buf != NULL )
kfree(buf);
out2:
set_fs(oldfs);
return error;
###################################
Thanks in advance.
Rgda,
Madhu V
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This archive was generated by hypermail 2b29 : Tue Dec 31 2002 - 22:00:19 EST