aboutsummaryrefslogtreecommitdiff
path: root/lib/sanitizer_common/sanitizer_symbolizer_libcdep.cc
blob: 7c377a729638d269f6425ade168c7b1e68b52d8b (plain) (blame)
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
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
//===-- sanitizer_symbolizer_libcdep.cc -----------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
//===----------------------------------------------------------------------===//

#include "sanitizer_allocator_internal.h"
#include "sanitizer_internal_defs.h"
#include "sanitizer_symbolizer_internal.h"

namespace __sanitizer {

const char *ExtractToken(const char *str, const char *delims, char **result) {
  uptr prefix_len = internal_strcspn(str, delims);
  *result = (char*)InternalAlloc(prefix_len + 1);
  internal_memcpy(*result, str, prefix_len);
  (*result)[prefix_len] = '\0';
  const char *prefix_end = str + prefix_len;
  if (*prefix_end != '\0') prefix_end++;
  return prefix_end;
}

const char *ExtractInt(const char *str, const char *delims, int *result) {
  char *buff;
  const char *ret = ExtractToken(str, delims, &buff);
  if (buff != 0) {
    *result = (int)internal_atoll(buff);
  }
  InternalFree(buff);
  return ret;
}

const char *ExtractUptr(const char *str, const char *delims, uptr *result) {
  char *buff;
  const char *ret = ExtractToken(str, delims, &buff);
  if (buff != 0) {
    *result = (uptr)internal_atoll(buff);
  }
  InternalFree(buff);
  return ret;
}

const char *ExtractTokenUpToDelimiter(const char *str, const char *delimiter,
                                      char **result) {
  const char *found_delimiter = internal_strstr(str, delimiter);
  uptr prefix_len =
      found_delimiter ? found_delimiter - str : internal_strlen(str);
  *result = (char *)InternalAlloc(prefix_len + 1);
  internal_memcpy(*result, str, prefix_len);
  (*result)[prefix_len] = '\0';
  const char *prefix_end = str + prefix_len;
  if (*prefix_end != '\0') prefix_end += internal_strlen(delimiter);
  return prefix_end;
}

SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
  BlockingMutexLock l(&mu_);
  const char *module_name;
  uptr module_offset;
  ModuleArch arch;
  SymbolizedStack *res = SymbolizedStack::New(addr);
  if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset,
                                         &arch))
    return res;
  // Always fill data about module name and offset.
  res->info.FillModuleInfo(module_name, module_offset, arch);
  for (auto &tool : tools_) {
    SymbolizerScope sym_scope(this);
    if (tool.SymbolizePC(addr, res)) {
      return res;
    }
  }
  return res;
}

bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
  BlockingMutexLock l(&mu_);
  const char *module_name;
  uptr module_offset;
  ModuleArch arch;
  if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset,
                                         &arch))
    return false;
  info->Clear();
  info->module = internal_strdup(module_name);
  info->module_offset = module_offset;
  info->module_arch = arch;
  for (auto &tool : tools_) {
    SymbolizerScope sym_scope(this);
    if (tool.SymbolizeData(addr, info)) {
      return true;
    }
  }
  return true;
}

bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
                                             uptr *module_address) {
  BlockingMutexLock l(&mu_);
  const char *internal_module_name = nullptr;
  ModuleArch arch;
  if (!FindModuleNameAndOffsetForAddress(pc, &internal_module_name,
                                         module_address, &arch))
    return false;

  if (module_name)
    *module_name = module_names_.GetOwnedCopy(internal_module_name);
  return true;
}

void Symbolizer::Flush() {
  BlockingMutexLock l(&mu_);
  for (auto &tool : tools_) {
    SymbolizerScope sym_scope(this);
    tool.Flush();
  }
}

const char *Symbolizer::Demangle(const char *name) {
  BlockingMutexLock l(&mu_);
  for (auto &tool : tools_) {
    SymbolizerScope sym_scope(this);
    if (const char *demangled = tool.Demangle(name))
      return demangled;
  }
  return PlatformDemangle(name);
}

void Symbolizer::PrepareForSandboxing() {
  BlockingMutexLock l(&mu_);
  PlatformPrepareForSandboxing();
}

bool Symbolizer::FindModuleNameAndOffsetForAddress(uptr address,
                                                   const char **module_name,
                                                   uptr *module_offset,
                                                   ModuleArch *module_arch) {
  const LoadedModule *module = FindModuleForAddress(address);
  if (module == nullptr)
    return false;
  *module_name = module->full_name();
  *module_offset = address - module->base_address();
  *module_arch = module->arch();
  return true;
}

const LoadedModule *Symbolizer::FindModuleForAddress(uptr address) {
  bool modules_were_reloaded = false;
  if (!modules_fresh_) {
    modules_.init();
    RAW_CHECK(modules_.size() > 0);
    modules_fresh_ = true;
    modules_were_reloaded = true;
  }
  for (uptr i = 0; i < modules_.size(); i++) {
    if (modules_[i].containsAddress(address)) {
      return &modules_[i];
    }
  }
  // Reload the modules and look up again, if we haven't tried it yet.
  if (!modules_were_reloaded) {
    // FIXME: set modules_fresh_ from dlopen()/dlclose() interceptors.
    // It's too aggressive to reload the list of modules each time we fail
    // to find a module for a given address.
    modules_fresh_ = false;
    return FindModuleForAddress(address);
  }
  return 0;
}

Symbolizer *Symbolizer::GetOrInit() {
  SpinMutexLock l(&init_mu_);
  if (symbolizer_)
    return symbolizer_;
  symbolizer_ = PlatformInit();
  CHECK(symbolizer_);
  return symbolizer_;
}

// For now we assume the following protocol:
// For each request of the form
//   <module_name> <module_offset>
// passed to STDIN, external symbolizer prints to STDOUT response:
//   <function_name>
//   <file_name>:<line_number>:<column_number>
//   <function_name>
//   <file_name>:<line_number>:<column_number>
//   ...
//   <empty line>
class LLVMSymbolizerProcess : public SymbolizerProcess {
 public:
  explicit LLVMSymbolizerProcess(const char *path) : SymbolizerProcess(path) {}

 private:
  bool ReachedEndOfOutput(const char *buffer, uptr length) const override {
    // Empty line marks the end of llvm-symbolizer output.
    return length >= 2 && buffer[length - 1] == '\n' &&
           buffer[length - 2] == '\n';
  }

  // When adding a new architecture, don't forget to also update
  // script/asan_symbolize.py and sanitizer_common.h.
  void GetArgV(const char *path_to_binary,
               const char *(&argv)[kArgVMax]) const override {
#if defined(__x86_64h__)
    const char* const kSymbolizerArch = "--default-arch=x86_64h";
#elif defined(__x86_64__)
    const char* const kSymbolizerArch = "--default-arch=x86_64";
#elif defined(__i386__)
    const char* const kSymbolizerArch = "--default-arch=i386";
#elif defined(__aarch64__)
    const char* const kSymbolizerArch = "--default-arch=arm64";
#elif defined(__arm__)
    const char* const kSymbolizerArch = "--default-arch=arm";
#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
    const char* const kSymbolizerArch = "--default-arch=powerpc64";
#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
    const char* const kSymbolizerArch = "--default-arch=powerpc64le";
#elif defined(__s390x__)
    const char* const kSymbolizerArch = "--default-arch=s390x";
#elif defined(__s390__)
    const char* const kSymbolizerArch = "--default-arch=s390";
#else
    const char* const kSymbolizerArch = "--default-arch=unknown";
#endif

    const char *const inline_flag = common_flags()->symbolize_inline_frames
                                        ? "--inlining=true"
                                        : "--inlining=false";
    int i = 0;
    argv[i++] = path_to_binary;
    argv[i++] = inline_flag;
    argv[i++] = kSymbolizerArch;
    argv[i++] = nullptr;
  }
};

LLVMSymbolizer::LLVMSymbolizer(const char *path, LowLevelAllocator *allocator)
    : symbolizer_process_(new(*allocator) LLVMSymbolizerProcess(path)) {}

// Parse a <file>:<line>[:<column>] buffer. The file path may contain colons on
// Windows, so extract tokens from the right hand side first. The column info is
// also optional.
static const char *ParseFileLineInfo(AddressInfo *info, const char *str) {
  char *file_line_info = 0;
  str = ExtractToken(str, "\n", &file_line_info);
  CHECK(file_line_info);

  if (uptr size = internal_strlen(file_line_info)) {
    char *back = file_line_info + size - 1;
    for (int i = 0; i < 2; ++i) {
      while (back > file_line_info && IsDigit(*back)) --back;
      if (*back != ':' || !IsDigit(back[1])) break;
      info->column = info->line;
      info->line = internal_atoll(back + 1);
      // Truncate the string at the colon to keep only filename.
      *back = '\0';
      --back;
    }
    ExtractToken(file_line_info, "", &info->file);
  }

  InternalFree(file_line_info);
  return str;
}

// Parses one or more two-line strings in the following format:
//   <function_name>
//   <file_name>:<line_number>[:<column_number>]
// Used by LLVMSymbolizer, Addr2LinePool and InternalSymbolizer, since all of
// them use the same output format.
void ParseSymbolizePCOutput(const char *str, SymbolizedStack *res) {
  bool top_frame = true;
  SymbolizedStack *last = res;
  while (true) {
    char *function_name = 0;
    str = ExtractToken(str, "\n", &function_name);
    CHECK(function_name);
    if (function_name[0] == '\0') {
      // There are no more frames.
      InternalFree(function_name);
      break;
    }
    SymbolizedStack *cur;
    if (top_frame) {
      cur = res;
      top_frame = false;
    } else {
      cur = SymbolizedStack::New(res->info.address);
      cur->info.FillModuleInfo(res->info.module, res->info.module_offset,
                               res->info.module_arch);
      last->next = cur;
      last = cur;
    }

    AddressInfo *info = &cur->info;
    info->function = function_name;
    str = ParseFileLineInfo(info, str);

    // Functions and filenames can be "??", in which case we write 0
    // to address info to mark that names are unknown.
    if (0 == internal_strcmp(info->function, "??")) {
      InternalFree(info->function);
      info->function = 0;
    }
    if (0 == internal_strcmp(info->file, "??")) {
      InternalFree(info->file);
      info->file = 0;
    }
  }
}

// Parses a two-line string in the following format:
//   <symbol_name>
//   <start_address> <size>
// Used by LLVMSymbolizer and InternalSymbolizer.
void ParseSymbolizeDataOutput(const char *str, DataInfo *info) {
  str = ExtractToken(str, "\n", &info->name);
  str = ExtractUptr(str, " ", &info->start);
  str = ExtractUptr(str, "\n", &info->size);
}

bool LLVMSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
  AddressInfo *info = &stack->info;
  const char *buf = FormatAndSendCommand(
      /*is_data*/ false, info->module, info->module_offset, info->module_arch);
  if (buf) {
    ParseSymbolizePCOutput(buf, stack);
    return true;
  }
  return false;
}

bool LLVMSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
  const char *buf = FormatAndSendCommand(
      /*is_data*/ true, info->module, info->module_offset, info->module_arch);
  if (buf) {
    ParseSymbolizeDataOutput(buf, info);
    info->start += (addr - info->module_offset); // Add the base address.
    return true;
  }
  return false;
}

const char *LLVMSymbolizer::FormatAndSendCommand(bool is_data,
                                                 const char *module_name,
                                                 uptr module_offset,
                                                 ModuleArch arch) {
  CHECK(module_name);
  const char *is_data_str = is_data ? "DATA " : "";
  if (arch == kModuleArchUnknown) {
    internal_snprintf(buffer_, kBufferSize, "%s\"%s\" 0x%zx\n", is_data_str,
                      module_name, module_offset);
  } else {
    internal_snprintf(buffer_, kBufferSize, "%s\"%s:%s\" 0x%zx\n", is_data_str,
                      module_name, ModuleArchToString(arch), module_offset);
  }
  return symbolizer_process_->SendCommand(buffer_);
}

SymbolizerProcess::SymbolizerProcess(const char *path, bool use_forkpty)
    : path_(path),
      input_fd_(kInvalidFd),
      output_fd_(kInvalidFd),
      times_restarted_(0),
      failed_to_start_(false),
      reported_invalid_path_(false),
      use_forkpty_(use_forkpty) {
  CHECK(path_);
  CHECK_NE(path_[0], '\0');
}

const char *SymbolizerProcess::SendCommand(const char *command) {
  for (; times_restarted_ < kMaxTimesRestarted; times_restarted_++) {
    // Start or restart symbolizer if we failed to send command to it.
    if (const char *res = SendCommandImpl(command))
      return res;
    Restart();
  }
  if (!failed_to_start_) {
    Report("WARNING: Failed to use and restart external symbolizer!\n");
    failed_to_start_ = true;
  }
  return 0;
}

const char *SymbolizerProcess::SendCommandImpl(const char *command) {
  if (input_fd_ == kInvalidFd || output_fd_ == kInvalidFd)
      return 0;
  if (!WriteToSymbolizer(command, internal_strlen(command)))
      return 0;
  if (!ReadFromSymbolizer(buffer_, kBufferSize))
      return 0;
  return buffer_;
}

bool SymbolizerProcess::Restart() {
  if (input_fd_ != kInvalidFd)
    CloseFile(input_fd_);
  if (output_fd_ != kInvalidFd)
    CloseFile(output_fd_);
  return StartSymbolizerSubprocess();
}

bool SymbolizerProcess::ReadFromSymbolizer(char *buffer, uptr max_length) {
  if (max_length == 0)
    return true;
  uptr read_len = 0;
  while (true) {
    uptr just_read = 0;
    bool success = ReadFromFile(input_fd_, buffer + read_len,
                                max_length - read_len - 1, &just_read);
    // We can't read 0 bytes, as we don't expect external symbolizer to close
    // its stdout.
    if (!success || just_read == 0) {
      Report("WARNING: Can't read from symbolizer at fd %d\n", input_fd_);
      return false;
    }
    read_len += just_read;
    if (ReachedEndOfOutput(buffer, read_len))
      break;
  }
  buffer[read_len] = '\0';
  return true;
}

bool SymbolizerProcess::WriteToSymbolizer(const char *buffer, uptr length) {
  if (length == 0)
    return true;
  uptr write_len = 0;
  bool success = WriteToFile(output_fd_, buffer, length, &write_len);
  if (!success || write_len != length) {
    Report("WARNING: Can't write to symbolizer at fd %d\n", output_fd_);
    return false;
  }
  return true;
}

}  // namespace __sanitizer