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 #ifndef _LIBUNWINDSTACK_ELF_INTERFACE_ARM_H
18 #define _LIBUNWINDSTACK_ELF_INTERFACE_ARM_H
19 
20 #include <elf.h>
21 #include <stdint.h>
22 
23 #include <iterator>
24 #include <unordered_map>
25 
26 #include <unwindstack/ElfInterface.h>
27 #include <unwindstack/Memory.h>
28 
29 namespace unwindstack {
30 
31 class ElfInterfaceArm : public ElfInterface32 {
32  public:
ElfInterfaceArm(Memory * memory)33   ElfInterfaceArm(Memory* memory) : ElfInterface32(memory) {}
34   virtual ~ElfInterfaceArm() = default;
35 
36   class iterator : public std::iterator<std::bidirectional_iterator_tag, uint32_t> {
37    public:
iterator(ElfInterfaceArm * interface,size_t index)38     iterator(ElfInterfaceArm* interface, size_t index) : interface_(interface), index_(index) { }
39 
40     iterator& operator++() { index_++; return *this; }
41     iterator& operator++(int increment) { index_ += increment; return *this; }
42     iterator& operator--() { index_--; return *this; }
43     iterator& operator--(int decrement) { index_ -= decrement; return *this; }
44 
45     bool operator==(const iterator& rhs) { return this->index_ == rhs.index_; }
46     bool operator!=(const iterator& rhs) { return this->index_ != rhs.index_; }
47 
48     uint32_t operator*() {
49       uint32_t addr = interface_->addrs_[index_];
50       if (addr == 0) {
51         if (!interface_->GetPrel31Addr(interface_->start_offset_ + index_ * 8, &addr)) {
52           return 0;
53         }
54         interface_->addrs_[index_] = addr;
55       }
56       return addr;
57     }
58 
59    private:
60     ElfInterfaceArm* interface_ = nullptr;
61     size_t index_ = 0;
62   };
63 
begin()64   iterator begin() { return iterator(this, 0); }
end()65   iterator end() { return iterator(this, total_entries_); }
66 
67   bool Init(int64_t* section_bias) override;
68 
69   bool GetPrel31Addr(uint32_t offset, uint32_t* addr);
70 
71   bool FindEntry(uint32_t pc, uint64_t* entry_offset);
72 
73   void HandleUnknownType(uint32_t type, uint64_t ph_offset, uint64_t ph_filesz) override;
74 
75   bool Step(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished) override;
76 
77   bool StepExidx(uint64_t pc, Regs* regs, Memory* process_memory, bool* finished);
78 
79   bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* offset) override;
80 
start_offset()81   uint64_t start_offset() { return start_offset_; }
82 
total_entries()83   size_t total_entries() { return total_entries_; }
84 
set_load_bias(uint64_t load_bias)85   void set_load_bias(uint64_t load_bias) { load_bias_ = load_bias; }
86 
87  protected:
88   uint64_t start_offset_ = 0;
89   size_t total_entries_ = 0;
90   uint64_t load_bias_ = 0;
91 
92   std::unordered_map<size_t, uint32_t> addrs_;
93 };
94 
95 }  // namespace unwindstack
96 
97 #endif  // _LIBUNWINDSTACK_ELF_INTERFACE_ARM_H
98