1 //===-- Memory.h ------------------------------------------------*- 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 #ifndef liblldb_Memory_h_
10 #define liblldb_Memory_h_
11 
12 #include "lldb/Utility/RangeMap.h"
13 #include "lldb/lldb-private.h"
14 #include <map>
15 #include <mutex>
16 #include <vector>
17 
18 namespace lldb_private {
19 // A class to track memory that was read from a live process between
20 // runs.
21 class MemoryCache {
22 public:
23   // Constructors and Destructors
24   MemoryCache(Process &process);
25 
26   ~MemoryCache();
27 
28   void Clear(bool clear_invalid_ranges = false);
29 
30   void Flush(lldb::addr_t addr, size_t size);
31 
32   size_t Read(lldb::addr_t addr, void *dst, size_t dst_len, Status &error);
33 
34   uint32_t GetMemoryCacheLineSize() const { return m_L2_cache_line_byte_size; }
35 
36   void AddInvalidRange(lldb::addr_t base_addr, lldb::addr_t byte_size);
37 
38   bool RemoveInvalidRange(lldb::addr_t base_addr, lldb::addr_t byte_size);
39 
40   // Allow external sources to populate data into the L1 memory cache
41   void AddL1CacheData(lldb::addr_t addr, const void *src, size_t src_len);
42 
43   void AddL1CacheData(lldb::addr_t addr,
44                       const lldb::DataBufferSP &data_buffer_sp);
45 
46 protected:
47   typedef std::map<lldb::addr_t, lldb::DataBufferSP> BlockMap;
48   typedef RangeArray<lldb::addr_t, lldb::addr_t, 4> InvalidRanges;
49   typedef Range<lldb::addr_t, lldb::addr_t> AddrRange;
50   // Classes that inherit from MemoryCache can see and modify these
51   std::recursive_mutex m_mutex;
52   BlockMap m_L1_cache; // A first level memory cache whose chunk sizes vary that
53                        // will be used only if the memory read fits entirely in
54                        // a chunk
55   BlockMap m_L2_cache; // A memory cache of fixed size chinks
56                        // (m_L2_cache_line_byte_size bytes in size each)
57   InvalidRanges m_invalid_ranges;
58   Process &m_process;
59   uint32_t m_L2_cache_line_byte_size;
60 
61 private:
62   DISALLOW_COPY_AND_ASSIGN(MemoryCache);
63 };
64 
65 
66 
67 class AllocatedBlock {
68 public:
69   AllocatedBlock(lldb::addr_t addr, uint32_t byte_size, uint32_t permissions,
70                  uint32_t chunk_size);
71 
72   ~AllocatedBlock();
73 
74   lldb::addr_t ReserveBlock(uint32_t size);
75 
76   bool FreeBlock(lldb::addr_t addr);
77 
78   lldb::addr_t GetBaseAddress() const { return m_range.GetRangeBase(); }
79 
80   uint32_t GetByteSize() const { return m_range.GetByteSize(); }
81 
82   uint32_t GetPermissions() const { return m_permissions; }
83 
84   uint32_t GetChunkSize() const { return m_chunk_size; }
85 
86   bool Contains(lldb::addr_t addr) const {
87     return m_range.Contains(addr);
88   }
89 
90 protected:
91   uint32_t TotalChunks() const { return GetByteSize() / GetChunkSize(); }
92 
93   uint32_t CalculateChunksNeededForSize(uint32_t size) const {
94     return (size + m_chunk_size - 1) / m_chunk_size;
95   }
96   // Base address of this block of memory 4GB of chunk should be enough.
97   Range<lldb::addr_t, uint32_t> m_range;
98   // Permissions for this memory (logical OR of lldb::Permissions bits)
99   const uint32_t m_permissions;
100   // The size of chunks that the memory at m_addr is divied up into.
101   const uint32_t m_chunk_size;
102   // A sorted list of free address ranges.
103   RangeVector<lldb::addr_t, uint32_t> m_free_blocks;
104   // A sorted list of reserved address.
105   RangeVector<lldb::addr_t, uint32_t> m_reserved_blocks;
106 };
107 
108 // A class that can track allocated memory and give out allocated memory
109 // without us having to make an allocate/deallocate call every time we need
110 // some memory in a process that is being debugged.
111 class AllocatedMemoryCache {
112 public:
113   // Constructors and Destructors
114   AllocatedMemoryCache(Process &process);
115 
116   ~AllocatedMemoryCache();
117 
118   void Clear();
119 
120   lldb::addr_t AllocateMemory(size_t byte_size, uint32_t permissions,
121                               Status &error);
122 
123   bool DeallocateMemory(lldb::addr_t ptr);
124 
125 protected:
126   typedef std::shared_ptr<AllocatedBlock> AllocatedBlockSP;
127 
128   AllocatedBlockSP AllocatePage(uint32_t byte_size, uint32_t permissions,
129                                 uint32_t chunk_size, Status &error);
130 
131   // Classes that inherit from MemoryCache can see and modify these
132   Process &m_process;
133   std::recursive_mutex m_mutex;
134   typedef std::multimap<uint32_t, AllocatedBlockSP> PermissionsToBlockMap;
135   PermissionsToBlockMap m_memory_map;
136 
137 private:
138   DISALLOW_COPY_AND_ASSIGN(AllocatedMemoryCache);
139 };
140 
141 } // namespace lldb_private
142 
143 #endif // liblldb_Memory_h_
144