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
85