kernel/vm/vm_address_region.cpp

868     auto before_iter = subregions_.end();
872         if (CheckGapLocked(before_iter, after_iter, spot, base, align, size, 0, arch_mmu_flags)) {
880         before_iter = after_iter++;
881     } while (before_iter.IsValid());
977     auto before_iter = after_iter;
980         before_iter = subregions_.end();
982         --before_iter;
985     ASSERT(before_iter == subregions_.end() || before_iter.IsValid());
987     if (CheckGapLocked(before_iter, after_iter, spot, alloc_spot, align, size, 0,
1025             ChildList::iterator before_iter;
1029                 before_iter = subregions_.end();
1040                 before_iter = --subregions_.end();
1042                 DEBUG_ASSERT(before_iter.IsValid());
1045                 if (add_overflow(before_iter->base(), before_iter->size(), &base) ||
1053             if (CheckGapLocked(before_iter, after_iter, spot, chosen_base, align, size, 0,