/*
 *	use any slack space at the end of the process space due to memory
 *	allocator inefficiencies to implement a limited brk() function and
 *	maybe save some memory by using what we already have.
 *
 *	This does require a user space malloc that knows about brk() but
 *	doesn't rely on it exclusively.
 *
 *		davidm@lineo.com
 */

asmlinkage unsigned long sys_brk(unsigned long brk)
{
#ifdef maybe_later
	unsigned long rlim;
#endif
	struct mm_struct *mm = current->mm;

	if (brk < mm->end_code || brk < mm->start_brk || brk > mm->end_brk)
		return mm->brk;

	if (mm->brk == brk)
		return mm->brk;

	/*
	 * Always allow shrinking brk
	 */
	if (brk <= mm->brk) {
		mm->brk = brk;
		return brk;
	}

#ifdef maybe_later
	/*
	 * Check against rlimit and stack..
	 */
	rlim = current->rlim[RLIMIT_DATA].rlim_cur;
	if (rlim >= RLIM_INFINITY)
		rlim = ~0;
	if (brk - mm->end_code > rlim)
		return mm->brk;
#endif

	/*
	 * Ok, looks good - let it rip.
	 */
	return mm->brk = brk;
}