compiler-rt/lib/scudo/standalone/mem_map.cpp

   1 //===-- mem_map.cpp ---------------------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "mem_map.h"
  10
  11 #include "common.h"
  12
  13 namespace scudo {
  14
  15 bool MemMapDefault::mapImpl(uptr Addr, uptr Size, const char *Name,
  16                             uptr Flags) {
  17   void *MappedAddr =
  18       ::scudo::map(reinterpret_cast<void *>(Addr), Size, Name, Flags, &Data);
  19   if (MappedAddr == nullptr)
  20     return false;
  21   Base = reinterpret_cast<uptr>(MappedAddr);
  22   MappedBase = Base;
  23   Capacity = Size;
  24   return true;
  25 }
  26
  27 void MemMapDefault::unmapImpl(uptr Addr, uptr Size) {
  28   if (Size == Capacity) {
  29     Base = MappedBase = Capacity = 0;
  30   } else {
  31     if (Base == Addr) {
  32       Base = Addr + Size;
  33       MappedBase = MappedBase == 0 ? Base : Max(MappedBase, Base);
  34     }
  35     Capacity -= Size;
  36   }
  37
  38   ::scudo::unmap(reinterpret_cast<void *>(Addr), Size, UNMAP_ALL, &Data);
  39 }
  40
  41 bool MemMapDefault::remapImpl(uptr Addr, uptr Size, const char *Name,
  42                               uptr Flags) {
  43   void *RemappedPtr =
  44       ::scudo::map(reinterpret_cast<void *>(Addr), Size, Name, Flags, &Data);
  45   const uptr RemappedAddr = reinterpret_cast<uptr>(RemappedPtr);
  46   MappedBase = MappedBase == 0 ? RemappedAddr : Min(MappedBase, RemappedAddr);
  47   return RemappedAddr == Addr;
  48 }
  49
  50 void MemMapDefault::releaseAndZeroPagesToOSImpl(uptr From, uptr Size) {
  51   DCHECK_NE(MappedBase, 0U);
  52   DCHECK_GE(From, MappedBase);
  53   return ::scudo::releasePagesToOS(MappedBase, From - MappedBase, Size, &Data);
  54 }
  55
  56 void MemMapDefault::setMemoryPermissionImpl(uptr Addr, uptr Size, uptr Flags) {
  57   return ::scudo::setMemoryPermission(Addr, Size, Flags);
  58 }
  59
  60 void ReservedMemoryDefault::releaseImpl() {
  61   ::scudo::unmap(reinterpret_cast<void *>(Base), Capacity, UNMAP_ALL, &Data);
  62 }
  63
  64 bool ReservedMemoryDefault::createImpl(uptr Addr, uptr Size, const char *Name,
  65                                        uptr Flags) {
  66   void *Reserved = ::scudo::map(reinterpret_cast<void *>(Addr), Size, Name,
  67                                 Flags | MAP_NOACCESS, &Data);
  68   if (Reserved == nullptr)
  69     return false;
  70
  71   Base = reinterpret_cast<uptr>(Reserved);
  72   Capacity = Size;
  73
  74   return true;
  75 }
  76
  77 ReservedMemoryDefault::MemMapT ReservedMemoryDefault::dispatchImpl(uptr Addr,
  78                                                                    uptr Size) {
  79   ReservedMemoryDefault::MemMapT NewMap(Addr, Size);
  80   NewMap.setMapPlatformData(Data);
  81   return NewMap;
  82 }
  83
  84 } // namespace scudo