1 /*
2  * Copyright (C) 2015 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 _LIBBACKTRACE_UNWIND_OFFLINE_H
18 #define _LIBBACKTRACE_UNWIND_OFFLINE_H
19 
20 #include <libunwind.h>
21 #include <stdint.h>
22 #include <sys/types.h>
23 #include <ucontext.h>
24 
25 #include <unordered_map>
26 #include <unordered_set>
27 
28 #include <backtrace/Backtrace.h>
29 
30 struct Space {
31   uint64_t start;
32   uint64_t end;
33   const uint8_t* data;
34 
SpaceSpace35   Space() {
36     Clear();
37   }
38 
39   void Clear();
40   size_t Read(uint64_t addr, uint8_t* buffer, size_t size);
41 };
42 
43 struct DebugFrameInfo {
44   bool is_eh_frame;
45   struct EhFrame {
46     uint64_t eh_frame_hdr_vaddr;
47     uint64_t eh_frame_vaddr;
48     uint64_t fde_table_offset_in_eh_frame_hdr;
49     std::vector<uint8_t> eh_frame_hdr_data;
50     std::vector<uint8_t> eh_frame_data;
51     struct ProgramHeader {
52       uint64_t vaddr;
53       uint64_t file_offset;
54       uint64_t file_size;
55     };
56     std::vector<ProgramHeader> program_headers;
57   } eh_frame;
58 };
59 
60 class BacktraceOffline : public Backtrace {
61  public:
BacktraceOffline(pid_t pid,pid_t tid,BacktraceMap * map,const backtrace_stackinfo_t & stack,bool cache_file)62   BacktraceOffline(pid_t pid, pid_t tid, BacktraceMap* map, const backtrace_stackinfo_t& stack,
63                    bool cache_file)
64       : Backtrace(pid, tid, map),
65         cache_file_(cache_file),
66         context_(nullptr),
67         last_debug_frame_(nullptr) {
68     stack_space_.start = stack.start;
69     stack_space_.end = stack.end;
70     stack_space_.data = stack.data;
71   }
72 
~BacktraceOffline()73   virtual ~BacktraceOffline() {
74     if (last_debug_frame_ != nullptr) {
75       delete last_debug_frame_;
76     }
77   }
78 
79   bool Unwind(size_t num_ignore_frames, ucontext_t* context) override;
80 
81   bool ReadWord(uintptr_t ptr, word_t* out_value) override;
82 
83   size_t Read(uintptr_t addr, uint8_t* buffer, size_t bytes) override;
84 
85   bool FindProcInfo(unw_addr_space_t addr_space, uint64_t ip, unw_proc_info_t* proc_info,
86                     int need_unwind_info);
87 
88   bool ReadReg(size_t reg_index, uint64_t* value);
89 
90  protected:
91   std::string GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) override;
92   DebugFrameInfo* GetDebugFrameInFile(const std::string& filename);
93 
94   static std::unordered_map<std::string, std::unique_ptr<DebugFrameInfo>> debug_frames_;
95   static std::unordered_set<std::string> debug_frame_missing_files_;
96 
97   bool cache_file_;
98   ucontext_t* context_;
99   Space eh_frame_hdr_space_;
100   Space eh_frame_space_;
101   Space stack_space_;
102   DebugFrameInfo* last_debug_frame_;
103 };
104 
105 #endif  // _LIBBACKTRACE_BACKTRACE_OFFLINE_H
106