aboutsummaryrefslogtreecommitdiff
path: root/src/processor/fast_source_line_resolver.cc
blob: 45c1f0f0a4996f9d44e4eb4ad71dc5093f4b397d (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
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
// 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.
//
// fast_source_line_resolver.cc: FastSourceLineResolver is a concrete class that
// implements SourceLineResolverInterface.  Both FastSourceLineResolver and
// BasicSourceLineResolver inherit from SourceLineResolverBase class to reduce
// code redundancy.
//
// See fast_source_line_resolver.h and fast_source_line_resolver_types.h
// for more documentation.
//
// Author: Siyang Xie (lambxsy@google.com)

#include "google_breakpad/processor/fast_source_line_resolver.h"
#include "processor/fast_source_line_resolver_types.h"

#include <map>
#include <utility>

#include "processor/module_factory.h"
#include "processor/scoped_ptr.h"

using std::map;
using std::make_pair;

namespace google_breakpad {

FastSourceLineResolver::FastSourceLineResolver()
  : SourceLineResolverBase(new FastModuleFactory) { }

bool FastSourceLineResolver::ShouldDeleteMemoryBufferAfterLoadModule() {
  return false;
}

void FastSourceLineResolver::Module::LookupAddress(StackFrame *frame) const {
  MemAddr address = frame->instruction - frame->module->base_address();

  // First, look for a FUNC record that covers address. Use
  // RetrieveNearestRange instead of RetrieveRange so that, if there
  // is no such function, we can use the next function to bound the
  // extent of the PUBLIC symbol we find, below. This does mean we
  // need to check that address indeed falls within the function we
  // find; do the range comparison in an overflow-friendly way.
  scoped_ptr<Function> func(new Function);
  const Function* func_ptr = 0;
  scoped_ptr<PublicSymbol> public_symbol(new PublicSymbol);
  const PublicSymbol* public_symbol_ptr = 0;
  MemAddr function_base;
  MemAddr function_size;
  MemAddr public_address;

  if (functions_.RetrieveNearestRange(address, func_ptr,
                                      &function_base, &function_size) &&
      address >= function_base && address - function_base < function_size) {
    func.get()->CopyFrom(func_ptr);
    frame->function_name = func->name;
    frame->function_base = frame->module->base_address() + function_base;

    scoped_ptr<Line> line(new Line);
    const Line* line_ptr = 0;
    MemAddr line_base;
    if (func->lines.RetrieveRange(address, line_ptr, &line_base, NULL)) {
      line.get()->CopyFrom(line_ptr);
      FileMap::iterator it = files_.find(line->source_file_id);
      if (it != files_.end()) {
        frame->source_file_name =
            files_.find(line->source_file_id).GetValuePtr();
      }
      frame->source_line = line->line;
      frame->source_line_base = frame->module->base_address() + line_base;
    }
  } else if (public_symbols_.Retrieve(address,
                                      public_symbol_ptr, &public_address) &&
             (!func_ptr || public_address > function_base)) {
    public_symbol.get()->CopyFrom(public_symbol_ptr);
    frame->function_name = public_symbol->name;
    frame->function_base = frame->module->base_address() + public_address;
  }
}

// WFI: WindowsFrameInfo.
// Returns a WFI object reading from a raw memory chunk of data
WindowsFrameInfo FastSourceLineResolver::CopyWFI(const char *raw) {
  // The first 4Bytes of int data are unused.
  // They corresponds to "int valid;" data member of WFI.
  const u_int32_t *para_uint32 = reinterpret_cast<const u_int32_t*>(
      raw + sizeof(int32_t));

  u_int32_t prolog_size = para_uint32[0];;
  u_int32_t epilog_size = para_uint32[1];
  u_int32_t parameter_size = para_uint32[2];
  u_int32_t saved_register_size = para_uint32[3];
  u_int32_t local_size = para_uint32[4];
  u_int32_t max_stack_size = para_uint32[5];
  const char *boolean = reinterpret_cast<const char*>(para_uint32 + 6);
  bool allocates_base_pointer = (*boolean != 0);
  std::string program_string = boolean + 1;

  return WindowsFrameInfo(prolog_size,
                          epilog_size,
                          parameter_size,
                          saved_register_size,
                          local_size,
                          max_stack_size,
                          allocates_base_pointer,
                          program_string);
}

// Loads a map from the given buffer in char* type.
// Does NOT take ownership of mem_buffer.
// In addition, treat mem_buffer as const char*.
bool FastSourceLineResolver::Module::LoadMapFromMemory(char *mem_buffer) {
  if (!mem_buffer) return false;

  const u_int32_t *map_sizes = reinterpret_cast<const u_int32_t*>(mem_buffer);

  unsigned int header_size = kNumberMaps_ * sizeof(unsigned int);

  // offsets[]: an array of offset addresses (with respect to mem_buffer),
  // for each "Static***Map" component of Module.
  // "Static***Map": static version of std::map or map wrapper, i.e., StaticMap,
  // StaticAddressMap, StaticContainedRangeMap, and StaticRangeMap.
  unsigned int offsets[kNumberMaps_];
  offsets[0] = header_size;
  for (int i = 1; i < kNumberMaps_; ++i) {
    offsets[i] = offsets[i - 1] + map_sizes[i - 1];
  }

  // Use pointers to construct Static*Map data members in Module:
  int map_id = 0;
  files_ = StaticMap<int, char>(mem_buffer + offsets[map_id++]);
  functions_ =
      StaticRangeMap<MemAddr, Function>(mem_buffer + offsets[map_id++]);
  public_symbols_ =
      StaticAddressMap<MemAddr, PublicSymbol>(mem_buffer + offsets[map_id++]);
  for (int i = 0; i < WindowsFrameInfo::STACK_INFO_LAST; ++i)
    windows_frame_info_[i] =
        StaticContainedRangeMap<MemAddr, char>(mem_buffer + offsets[map_id++]);

  cfi_initial_rules_ =
      StaticRangeMap<MemAddr, char>(mem_buffer + offsets[map_id++]);
  cfi_delta_rules_ = StaticMap<MemAddr, char>(mem_buffer + offsets[map_id++]);

  return true;
}

WindowsFrameInfo *FastSourceLineResolver::Module::FindWindowsFrameInfo(
    const StackFrame *frame) const {
  MemAddr address = frame->instruction - frame->module->base_address();
  scoped_ptr<WindowsFrameInfo> result(new WindowsFrameInfo());

  // We only know about WindowsFrameInfo::STACK_INFO_FRAME_DATA and
  // WindowsFrameInfo::STACK_INFO_FPO. Prefer them in this order.
  // WindowsFrameInfo::STACK_INFO_FRAME_DATA is the newer type that
  // includes its own program string.
  // WindowsFrameInfo::STACK_INFO_FPO is the older type
  // corresponding to the FPO_DATA struct. See stackwalker_x86.cc.
  const char* frame_info_ptr;
  if ((windows_frame_info_[WindowsFrameInfo::STACK_INFO_FRAME_DATA]
       .RetrieveRange(address, frame_info_ptr))
      || (windows_frame_info_[WindowsFrameInfo::STACK_INFO_FPO]
          .RetrieveRange(address, frame_info_ptr))) {
    result->CopyFrom(CopyWFI(frame_info_ptr));
    return result.release();
  }

  // Even without a relevant STACK line, many functions contain
  // information about how much space their parameters consume on the
  // stack. Use RetrieveNearestRange instead of RetrieveRange, so that
  // we can use the function to bound the extent of the PUBLIC symbol,
  // below. However, this does mean we need to check that ADDRESS
  // falls within the retrieved function's range; do the range
  // comparison in an overflow-friendly way.
  scoped_ptr<Function> function(new Function);
  const Function* function_ptr = 0;
  MemAddr function_base, function_size;
  if (functions_.RetrieveNearestRange(address, function_ptr,
                                      &function_base, &function_size) &&
      address >= function_base && address - function_base < function_size) {
    function.get()->CopyFrom(function_ptr);
    result->parameter_size = function->parameter_size;
    result->valid |= WindowsFrameInfo::VALID_PARAMETER_SIZE;
    return result.release();
  }

  // PUBLIC symbols might have a parameter size. Use the function we
  // found above to limit the range the public symbol covers.
  scoped_ptr<PublicSymbol> public_symbol(new PublicSymbol);
  const PublicSymbol* public_symbol_ptr = 0;
  MemAddr public_address;
  if (public_symbols_.Retrieve(address, public_symbol_ptr, &public_address) &&
      (!function_ptr || public_address > function_base)) {
    public_symbol.get()->CopyFrom(public_symbol_ptr);
    result->parameter_size = public_symbol->parameter_size;
  }

  return NULL;
}

CFIFrameInfo *FastSourceLineResolver::Module::FindCFIFrameInfo(
    const StackFrame *frame) const {
  MemAddr address = frame->instruction - frame->module->base_address();
  MemAddr initial_base, initial_size;
  const char* initial_rules = NULL;

  // Find the initial rule whose range covers this address. That
  // provides an initial set of register recovery rules. Then, walk
  // forward from the initial rule's starting address to frame's
  // instruction address, applying delta rules.
  if (!cfi_initial_rules_.RetrieveRange(address, initial_rules,
                                        &initial_base, &initial_size)) {
    return NULL;
  }

  // Create a frame info structure, and populate it with the rules from
  // the STACK CFI INIT record.
  scoped_ptr<CFIFrameInfo> rules(new CFIFrameInfo());
  if (!ParseCFIRuleSet(initial_rules, rules.get()))
    return NULL;

  // Find the first delta rule that falls within the initial rule's range.
  StaticMap<MemAddr, char>::iterator delta =
    cfi_delta_rules_.lower_bound(initial_base);

  // Apply delta rules up to and including the frame's address.
  while (delta != cfi_delta_rules_.end() && delta.GetKey() <= address) {
    ParseCFIRuleSet(delta.GetValuePtr(), rules.get());
    delta++;
  }

  return rules.release();
}

}  // namespace google_breakpad