1 //===---- EPCGenericRTDyldMemoryManager.h - EPC-based MemMgr ----*- 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 // Defines a RuntimeDyld::MemoryManager that uses EPC and the ORC runtime
10 // bootstrap functions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_EXECUTIONENGINE_ORC_EPCGENERICRTDYLDMEMORYMANAGER_H
15 #define LLVM_EXECUTIONENGINE_ORC_EPCGENERICRTDYLDMEMORYMANAGER_H
16 
17 #include "llvm/ExecutionEngine/Orc/ExecutorProcessControl.h"
18 #include "llvm/ExecutionEngine/RuntimeDyld.h"
19 
20 #define DEBUG_TYPE "orc"
21 
22 namespace llvm {
23 namespace orc {
24 
25 /// Remote-mapped RuntimeDyld-compatible memory manager.
26 class EPCGenericRTDyldMemoryManager : public RuntimeDyld::MemoryManager {
27 public:
28   /// Symbol addresses for memory access.
29   struct SymbolAddrs {
30     ExecutorAddr Instance;
31     ExecutorAddr Reserve;
32     ExecutorAddr Finalize;
33     ExecutorAddr Deallocate;
34     ExecutorAddr RegisterEHFrame;
35     ExecutorAddr DeregisterEHFrame;
36   };
37 
38   /// Create an EPCGenericRTDyldMemoryManager using the given EPC, looking up
39   /// the default symbol names in the bootstrap symbol set.
40   static Expected<std::unique_ptr<EPCGenericRTDyldMemoryManager>>
41   CreateWithDefaultBootstrapSymbols(ExecutorProcessControl &EPC);
42 
43   /// Create an EPCGenericRTDyldMemoryManager using the given EPC and symbol
44   /// addrs.
45   EPCGenericRTDyldMemoryManager(ExecutorProcessControl &EPC, SymbolAddrs SAs);
46 
47   EPCGenericRTDyldMemoryManager(const EPCGenericRTDyldMemoryManager &) = delete;
48   EPCGenericRTDyldMemoryManager &
49   operator=(const EPCGenericRTDyldMemoryManager &) = delete;
50   EPCGenericRTDyldMemoryManager(EPCGenericRTDyldMemoryManager &&) = delete;
51   EPCGenericRTDyldMemoryManager &
52   operator=(EPCGenericRTDyldMemoryManager &&) = delete;
53   ~EPCGenericRTDyldMemoryManager();
54 
55   uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
56                                unsigned SectionID,
57                                StringRef SectionName) override;
58 
59   uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
60                                unsigned SectionID, StringRef SectionName,
61                                bool IsReadOnly) override;
62 
63   void reserveAllocationSpace(uintptr_t CodeSize, Align CodeAlign,
64                               uintptr_t RODataSize, Align RODataAlign,
65                               uintptr_t RWDataSize, Align RWDataAlign) override;
66 
67   bool needsToReserveAllocationSpace() override;
68 
69   void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override;
70 
71   void deregisterEHFrames() override;
72 
73   void notifyObjectLoaded(RuntimeDyld &Dyld,
74                           const object::ObjectFile &Obj) override;
75 
76   bool finalizeMemory(std::string *ErrMsg = nullptr) override;
77 
78 private:
79   struct SectionAlloc {
80   public:
81     SectionAlloc(uint64_t Size, unsigned Align)
82         : Size(Size), Align(Align),
83           Contents(std::make_unique<uint8_t[]>(Size + Align - 1)) {}
84 
85     uint64_t Size;
86     unsigned Align;
87     std::unique_ptr<uint8_t[]> Contents;
88     ExecutorAddr RemoteAddr;
89   };
90 
91   // Group of section allocations to be allocated together in the executor. The
92   // RemoteCodeAddr will stand in as the id of the group for deallocation
93   // purposes.
94   struct SectionAllocGroup {
95     SectionAllocGroup() = default;
96     SectionAllocGroup(const SectionAllocGroup &) = delete;
97     SectionAllocGroup &operator=(const SectionAllocGroup &) = delete;
98     SectionAllocGroup(SectionAllocGroup &&) = default;
99     SectionAllocGroup &operator=(SectionAllocGroup &&) = default;
100 
101     ExecutorAddrRange RemoteCode;
102     ExecutorAddrRange RemoteROData;
103     ExecutorAddrRange RemoteRWData;
104     std::vector<ExecutorAddrRange> UnfinalizedEHFrames;
105     std::vector<SectionAlloc> CodeAllocs, RODataAllocs, RWDataAllocs;
106   };
107 
108   // Maps all allocations in SectionAllocs to aligned blocks
109   void mapAllocsToRemoteAddrs(RuntimeDyld &Dyld,
110                               std::vector<SectionAlloc> &SecAllocs,
111                               ExecutorAddr NextAddr);
112 
113   ExecutorProcessControl &EPC;
114   SymbolAddrs SAs;
115 
116   std::mutex M;
117   std::vector<SectionAllocGroup> Unmapped;
118   std::vector<SectionAllocGroup> Unfinalized;
119   std::vector<ExecutorAddr> FinalizedAllocs;
120   std::string ErrMsg;
121 };
122 
123 } // end namespace orc
124 } // end namespace llvm
125 
126 #undef DEBUG_TYPE
127 
128 #endif // LLVM_EXECUTIONENGINE_ORC_EPCGENERICRTDYLDMEMORYMANAGER_H
129