1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <stdint.h>
20 
21 #include <memory>
22 #include <unordered_map>
23 #include <vector>
24 
25 #include <unwindstack/DwarfSection.h>
26 
27 namespace unwindstack {
28 
29 // Forward declarations.
30 class Memory;
31 struct SectionInfo;
32 
33 template <typename AddressType>
34 class DwarfEhFrameWithHdr : public DwarfSectionImpl<AddressType> {
35  public:
36   // Add these so that the protected members of DwarfSectionImpl
37   // can be accessed without needing a this->.
38   using DwarfSectionImpl<AddressType>::memory_;
39   using DwarfSectionImpl<AddressType>::last_error_;
40 
41   struct FdeInfo {
42     AddressType pc;
43     uint64_t offset;
44   };
45 
DwarfEhFrameWithHdr(std::shared_ptr<Memory> & memory)46   DwarfEhFrameWithHdr(std::shared_ptr<Memory>& memory) : DwarfSectionImpl<AddressType>(memory) {}
47   virtual ~DwarfEhFrameWithHdr() = default;
48 
GetCieOffsetFromFde32(uint32_t pointer)49   uint64_t GetCieOffsetFromFde32(uint32_t pointer) override {
50     return memory_.cur_offset() - pointer - 4;
51   }
52 
GetCieOffsetFromFde64(uint64_t pointer)53   uint64_t GetCieOffsetFromFde64(uint64_t pointer) override {
54     return memory_.cur_offset() - pointer - 8;
55   }
56 
AdjustPcFromFde(uint64_t pc)57   uint64_t AdjustPcFromFde(uint64_t pc) override {
58     // The eh_frame uses relative pcs.
59     return pc + memory_.cur_offset() - 4;
60   }
61 
62   bool EhFrameInit(const SectionInfo& info);
63   bool Init(const SectionInfo& info) override;
64 
65   const DwarfFde* GetFdeFromPc(uint64_t pc) override;
66 
67   bool GetFdeOffsetFromPc(uint64_t pc, uint64_t* fde_offset);
68 
69   const FdeInfo* GetFdeInfoFromIndex(size_t index);
70 
71   void GetFdes(std::vector<const DwarfFde*>* fdes) override;
72 
73  protected:
74   uint8_t version_ = 0;
75   uint8_t table_encoding_ = 0;
76   size_t table_entry_size_ = 0;
77 
78   uint64_t hdr_entries_offset_ = 0;
79   uint64_t hdr_entries_data_offset_ = 0;
80   uint64_t hdr_section_bias_ = 0;
81 
82   uint64_t fde_count_ = 0;
83   std::unordered_map<uint64_t, FdeInfo> fde_info_;
84 };
85 
86 }  // namespace unwindstack
87