int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
		   unsigned long arg4, unsigned long arg5, long *rc_p)
{
	long error = 0;

	switch (option) {
	case PR_CAPBSET_READ:
		if (!cap_valid(arg2))
			error = -EINVAL;
		else
			error = !!cap_raised(current->cap_bset, arg2);
		break;
#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
	case PR_CAPBSET_DROP:
		error = cap_prctl_drop(arg2);
		break;

	/*
	 * The next four prctl's remain to assist with transitioning a
	 * system from legacy UID=0 based privilege (when filesystem
	 * capabilities are not in use) to a system using filesystem
	 * capabilities only - as the POSIX.1e draft intended.
	 *
	 * Note:
	 *
	 *  PR_SET_SECUREBITS =
	 *      issecure_mask(SECURE_KEEP_CAPS_LOCKED)
	 *    | issecure_mask(SECURE_NOROOT)
	 *    | issecure_mask(SECURE_NOROOT_LOCKED)
	 *    | issecure_mask(SECURE_NO_SETUID_FIXUP)
	 *    | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)
	 *
	 * will ensure that the current process and all of its
	 * children will be locked into a pure
	 * capability-based-privilege environment.
	 */
	case PR_SET_SECUREBITS:
		if ((((current->securebits & SECURE_ALL_LOCKS) >> 1)
		     & (current->securebits ^ arg2))                  /*[1]*/
		    || ((current->securebits & SECURE_ALL_LOCKS
			 & ~arg2))                                    /*[2]*/
		    || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
		    || (cap_capable(current, CAP_SETPCAP) != 0)) {    /*[4]*/
			/*
			 * [1] no changing of bits that are locked
			 * [2] no unlocking of locks
			 * [3] no setting of unsupported bits
			 * [4] doing anything requires privilege (go read about
			 *     the "sendmail capabilities bug")
			 */
			error = -EPERM;  /* cannot change a locked bit */
		} else {
			current->securebits = arg2;
		}
		break;
	case PR_GET_SECUREBITS:
		error = current->securebits;
		break;

#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */

	case PR_GET_KEEPCAPS:
		if (issecure(SECURE_KEEP_CAPS))
			error = 1;
		break;
	case PR_SET_KEEPCAPS:
		if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */
			error = -EINVAL;
		else if (issecure(SECURE_KEEP_CAPS_LOCKED))
			error = -EPERM;
		else if (arg2)
			current->securebits |= issecure_mask(SECURE_KEEP_CAPS);
		else
			current->securebits &=
				~issecure_mask(SECURE_KEEP_CAPS);
		break;

	default:
		/* No functionality available - continue with default */
		return 0;
	}

	/* Functionality provided */
	*rc_p = error;
	return 1;
}
int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
		   unsigned long arg4, unsigned long arg5, long *rc_p)
{
	long error = 0;

	switch (option) {
	case PR_CAPBSET_READ:
		if (!cap_valid(arg2))
			error = -EINVAL;
		else
			error = !!cap_raised(current->cap_bset, arg2);
		break;
#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
	case PR_CAPBSET_DROP:
		error = cap_prctl_drop(arg2);
		break;

	 
	case PR_SET_SECUREBITS:
		if ((((current->securebits & SECURE_ALL_LOCKS) >> 1)
		     & (current->securebits ^ arg2))                   
		    || ((current->securebits & SECURE_ALL_LOCKS
			 & ~arg2))                                     
		    || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS))  
		    || (cap_capable(current, CAP_SETPCAP) != 0)) {     
			 
			error = -EPERM;   
		} else {
			current->securebits = arg2;
		}
		break;
	case PR_GET_SECUREBITS:
		error = current->securebits;
		break;

#endif  

	case PR_GET_KEEPCAPS:
		if (issecure(SECURE_KEEP_CAPS))
			error = 1;
		break;
	case PR_SET_KEEPCAPS:
		if (arg2 > 1)  
			error = -EINVAL;
		else if (issecure(SECURE_KEEP_CAPS_LOCKED))
			error = -EPERM;
		else if (arg2)
			current->securebits |= issecure_mask(SECURE_KEEP_CAPS);
		else
			current->securebits &=
				~issecure_mask(SECURE_KEEP_CAPS);
		break;

	default:
		 
		return 0;
	}

	 
	*rc_p = error;
	return 1;
}