Re: quotactl hook

chrisat_private

* Stephen Smalley (sdsat_private) wrote:
> 
> 
> On Sun, 2 Sep 2001, Greg KH wrote:
> 
> > int my_module_task_alloc_security (struct task_struct *p)
> > {
> > 	down (&task_semaphore);
> > 	if (p->security == NULL) {
> > 		p->security = kmalloc (sizeof (struct my_task_security_struct));
> > 		if (p->security == NULL) {
> > 			up (&task_semaphore);
> > 			return -ENOMEM;
> > 		}
> > 		init_MUTEX (&p->security->semaphore);
> > 		/* init the rest of your stuff */
> > 		...
> > 	}
> > 	up (&task_semaphore);
> > 	return 0;
> > }
> 
> I tried doing something along these lines in the SELinux module, and ran
> into another problem (besides the interrupt issue).  Since do_fork does a
> '*p = *current;' and we do not clear p->security before calling 
> security_ops->task_ops->alloc_security(p), the module task_alloc_security 
> function above will incorrectly assume that the security blob is already
> set rather than allocating a new blob for the new process.  So perhaps we
> should explicitly clear p->security in do_fork before calling the hook?

that makes sense to me.

-chris

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