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, uint32_t CodeAlign,
64                               uintptr_t RODataSize, uint32_t RODataAlign,
65                               uintptr_t RWDataSize,
66                               uint32_t RWDataAlign) override;
67 
68   bool needsToReserveAllocationSpace() override;
69 
70   void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override;
71 
72   void deregisterEHFrames() override;
73 
74   void notifyObjectLoaded(RuntimeDyld &Dyld,
75                           const object::ObjectFile &Obj) override;
76 
77   bool finalizeMemory(std::string *ErrMsg = nullptr) override;
78 
79 private:
80   struct Alloc {
81   public:
AllocAlloc82     Alloc(uint64_t Size, unsigned Align)
83         : Size(Size), Align(Align),
84           Contents(std::make_unique<uint8_t[]>(Size + Align - 1)) {}
85 
86     uint64_t Size;
87     unsigned Align;
88     std::unique_ptr<uint8_t[]> Contents;
89     ExecutorAddr RemoteAddr;
90   };
91 
92   struct EHFrame {
93     ExecutorAddr Addr;
94     uint64_t Size;
95   };
96 
97   // Group of section allocations to be allocated together in the executor. The
98   // RemoteCodeAddr will stand in as the id of the group for deallocation
99   // purposes.
100   struct AllocGroup {
101     AllocGroup() = default;
102     AllocGroup(const AllocGroup &) = delete;
103     AllocGroup &operator=(const AllocGroup &) = delete;
104     AllocGroup(AllocGroup &&) = default;
105     AllocGroup &operator=(AllocGroup &&) = default;
106 
107     ExecutorAddrRange RemoteCode;
108     ExecutorAddrRange RemoteROData;
109     ExecutorAddrRange RemoteRWData;
110     std::vector<EHFrame> UnfinalizedEHFrames;
111     std::vector<Alloc> CodeAllocs, RODataAllocs, RWDataAllocs;
112   };
113 
114   // Maps all allocations in Allocs to aligned blocks
115   void mapAllocsToRemoteAddrs(RuntimeDyld &Dyld, std::vector<Alloc> &Allocs,
116                               ExecutorAddr NextAddr);
117 
118   ExecutorProcessControl &EPC;
119   SymbolAddrs SAs;
120 
121   std::mutex M;
122   std::vector<AllocGroup> Unmapped;
123   std::vector<AllocGroup> Unfinalized;
124   std::vector<ExecutorAddr> FinalizedAllocs;
125   std::string ErrMsg;
126 };
127 
128 } // end namespace orc
129 } // end namespace llvm
130 
131 #undef DEBUG_TYPE
132 
133 #endif // LLVM_EXECUTIONENGINE_ORC_EPCGENERICRTDYLDMEMORYMANAGER_H
134