kernel/vm/VMUserAddressSpace.cpp

420 VMUserAddressSpace::_RandomizeAddress(addr_t start, addr_t end,
423 	ASSERT((start & addr_t(alignment - 1)) == 0);
424 	ASSERT(start <= end);
426 	if (start == end)
427 		return start;
429 	addr_t range = end - start + 1;
439 	return start + random;
443 /*!	Finds a reserved area that covers the region spanned by \a start and
448 VMUserAddressSpace::_InsertAreaIntoReservedRegion(addr_t start, size_t size,
451 	VMUserArea* reserved = fAreas.FindClosest(start, true);
453 		|| !reserved->ContainsAddress(start)
454 		|| !reserved->ContainsAddress(start + size - 1)) {
468 	if (start == reserved->Base()) {
482 	} else if (start + size == reserved->Base() + reserved->Size()) {
485 		reserved->SetSize(start - reserved->Base());
497 		newReserved->SetBase(start + size);
499 			reserved->Base() + reserved->Size() - start - size);
502 		reserved->SetSize(start - reserved->Base());
507 	area->SetBase(start);
518 VMUserAddressSpace::_InsertAreaSlot(addr_t start, addr_t size, addr_t end,
522 	TRACE(("VMUserAddressSpace::_InsertAreaSlot: address space %p, start "
524 		this, start, size, end, addressSpec, area));
527 	if (start < fBase || size == 0 || end > fEndAddress
528 		|| start + (size - 1) > end)
533 		status_t status = _InsertAreaIntoReservedRegion(start, size, area,
551 	start = align_address(start, alignment);
558 		originalStart = start;
559 		start = _RandomizeAddress(start, end - size + 1, alignment, true);
561 		&& start <= fNextInsertHint && fNextInsertHint <= end - size + 1) {
562 		originalStart = start;
563 		start = fNextInsertHint;
566 	// walk up to the spot where we should start searching
568 	VMUserArea* next = fAreas.FindClosest(start + size, false);
570 			? fAreas.Previous(next) : fAreas.FindClosest(start + size, true);
590 				addr_t alignedBase = align_address(start, alignment);
593 				if (is_valid_spot(start, alignedBase, size, nextBase)) {
612 					alignment, addressSpec, start);
636 				alignment, addressSpec, start);
653 					start = USER_BASE_ANY;
655 				} else if (start == originalStart) {
656 					start = USER_BASE_ANY;
659 					start = originalStart;
665 					&& originalStart != 0 && start != originalStart) {
666 				start = originalStart;
671 				// TODO: it would make sense to start with the biggest of them
757 			if ((last == NULL || last->Base() + (last->Size() - 1) < start)
758 				&& (next == NULL || next->Base() > start + (size - 1))) {
760 				area->SetBase(start);