aboutsummaryrefslogtreecommitdiff
path: root/src/google_breakpad/processor/stackwalker.h
blob: 614e31b56c5d610cfb76957cea4f18db16dc8388 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
// Copyright (c) 2010 Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// stackwalker.h: Generic stackwalker.
//
// The Stackwalker class is an abstract base class providing common generic
// methods that apply to stacks from all systems.  Specific implementations
// will extend this class by providing GetContextFrame and GetCallerFrame
// methods to fill in system-specific data in a StackFrame structure.
// Stackwalker assembles these StackFrame strucutres into a CallStack.
//
// Author: Mark Mentovai


#ifndef GOOGLE_BREAKPAD_PROCESSOR_STACKWALKER_H__
#define GOOGLE_BREAKPAD_PROCESSOR_STACKWALKER_H__

#include <set>
#include <string>
#include "google_breakpad/common/breakpad_types.h"
#include "google_breakpad/processor/code_modules.h"
#include "google_breakpad/processor/memory_region.h"

namespace google_breakpad {

class CallStack;
class MinidumpContext;
class SourceLineResolverInterface;
struct StackFrame;
class SymbolSupplier;
class SystemInfo;

using std::set;


class Stackwalker {
 public:
  virtual ~Stackwalker() {}

  // Populates the given CallStack by calling GetContextFrame and
  // GetCallerFrame.  The frames are further processed to fill all available
  // data.  Returns true if the stackwalk completed, or false if it was
  // interrupted by SymbolSupplier::GetSymbolFile().
  bool Walk(CallStack *stack);

  // Returns a new concrete subclass suitable for the CPU that a stack was
  // generated on, according to the CPU type indicated by the context
  // argument.  If no suitable concrete subclass exists, returns NULL.
  static Stackwalker* StackwalkerForCPU(const SystemInfo *system_info,
                                        MinidumpContext *context,
                                        MemoryRegion *memory,
                                        const CodeModules *modules,
                                        SymbolSupplier *supplier,
                                        SourceLineResolverInterface *resolver);

  static void set_max_frames(u_int32_t max_frames) { max_frames_ = max_frames; }
  static u_int32_t max_frames() { return max_frames_; }

 protected:
  // system_info identifies the operating system, NULL or empty if unknown.
  // memory identifies a MemoryRegion that provides the stack memory
  // for the stack to walk.  modules, if non-NULL, is a CodeModules
  // object that is used to look up which code module each stack frame is
  // associated with.  supplier is an optional caller-supplied SymbolSupplier
  // implementation.  If supplier is NULL, source line info will not be
  // resolved.  resolver is an instance of SourceLineResolverInterface
  // (see source_line_resolver_interface.h and basic_source_line_resolver.h).
  // If resolver is NULL, source line info will not be resolved.
  Stackwalker(const SystemInfo *system_info,
              MemoryRegion *memory,
              const CodeModules *modules,
              SymbolSupplier *supplier,
              SourceLineResolverInterface *resolver);

  // This can be used to filter out potential return addresses when
  // the stack walker resorts to stack scanning.
  // Returns true if any of:
  // * This address is within a loaded module, but we don't have symbols
  //   for that module.
  // * This address is within a loaded module for which we have symbols,
  //   and falls inside a function in that module.
  // Returns false otherwise.
  bool InstructionAddressSeemsValid(u_int64_t address);

  template<typename InstructionType>
  bool ScanForReturnAddress(InstructionType location_start,
                            InstructionType *location_found,
                            InstructionType *ip_found) {
    const int kRASearchWords = 30;
    return ScanForReturnAddress(location_start, location_found, ip_found,
                                kRASearchWords);
  }

  // Scan the stack starting at location_start, looking for an address
  // that looks like a valid instruction pointer. Addresses must
  // 1) be contained in the current stack memory
  // 2) pass the checks in InstructionAddressSeemsValid
  //
  // Returns true if a valid-looking instruction pointer was found.
  // When returning true, sets location_found to the address at which
  // the value was found, and ip_found to the value contained at that
  // location in memory.
  template<typename InstructionType>
  bool ScanForReturnAddress(InstructionType location_start,
                            InstructionType *location_found,
                            InstructionType *ip_found,
                            int searchwords) {
    for (InstructionType location = location_start;
         location <= location_start + searchwords * sizeof(InstructionType);
         location += sizeof(InstructionType)) {
      InstructionType ip;
      if (!memory_->GetMemoryAtAddress(location, &ip))
        break;

      if (modules_ && modules_->GetModuleForAddress(ip) &&
          InstructionAddressSeemsValid(ip)) {

        *ip_found = ip;
        *location_found = location;
        return true;
      }
    }
    // nothing found
    return false;
  }

  // Information about the system that produced the minidump.  Subclasses
  // and the SymbolSupplier may find this information useful.
  const SystemInfo *system_info_;

  // The stack memory to walk.  Subclasses will require this region to
  // get information from the stack.
  MemoryRegion *memory_;

  // A list of modules, for populating each StackFrame's module information.
  // This field is optional and may be NULL.
  const CodeModules *modules_;

 protected:
  // The SourceLineResolver implementation.
  SourceLineResolverInterface *resolver_;

 private:
  // Obtains the context frame, the innermost called procedure in a stack
  // trace.  Returns NULL on failure.  GetContextFrame allocates a new
  // StackFrame (or StackFrame subclass), ownership of which is taken by
  // the caller.
  virtual StackFrame* GetContextFrame() = 0;

  // Obtains a caller frame.  Each call to GetCallerFrame should return the
  // frame that called the last frame returned by GetContextFrame or
  // GetCallerFrame.  To aid this purpose, stack contains the CallStack
  // made of frames that have already been walked.  GetCallerFrame should
  // return NULL on failure or when there are no more caller frames (when
  // the end of the stack has been reached).  GetCallerFrame allocates a new
  // StackFrame (or StackFrame subclass), ownership of which is taken by
  // the caller.
  virtual StackFrame* GetCallerFrame(const CallStack *stack) = 0;

  // The optional SymbolSupplier for resolving source line info.
  SymbolSupplier *supplier_;

  // A list of modules that we haven't found symbols for.  We track
  // this in order to avoid repeatedly looking them up again within
  // one minidump.
  set<std::string> no_symbol_modules_;

  // The maximum number of frames Stackwalker will walk through.
  // This defaults to 1024 to prevent infinite loops.
  static u_int32_t max_frames_;
};


}  // namespace google_breakpad


#endif  // GOOGLE_BREAKPAD_PROCESSOR_STACKWALKER_H__