On Wed, Nov 20, 2013 at 11:43 PM, Nav Kamal <navkamal90@xxxxxxxxx> wrote: > Am learning to write LKMs and wrote this program : > > #include<linux/init.h> > #include<linux/module.h> > static int module_entry(void){ > printk(KERN_ALERT "Hello World !!\n"); > return 0; > } > static void exit_module(void){ > printk(KERN_ALERT "Bye World .... \n"); > } > module_init(module_entry); > module_exit(exit_module); > > In this program if I change return value of function module_entry from 0 to > something negative, the module fails to load. The error message is : > > "insmod: ERROR: could not insert module test.ko: Operation not permitted" > > Failing to load module with negative return value is understandable but I > can't understand why it says "Operation not permitted". Its not about user > permissions, its about return value. Can somebody please guide me about this > ? AFAIK, insmod/modprobe translate any errors during module load as "not permitted". This doesn't mean you can not read the .ko files, it just means you can't load it. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies