File: sanitizer_symbolizer_posix_libcdep.cc

package info (click to toggle)
llvm-toolchain-7 1%3A7.0.1-8
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 733,456 kB
  • sloc: cpp: 3,776,651; ansic: 633,271; asm: 350,301; python: 142,716; objc: 107,612; sh: 22,626; lisp: 11,056; perl: 7,999; pascal: 6,742; ml: 5,537; awk: 3,536; makefile: 2,557; cs: 2,027; xml: 841; ruby: 156
file content (544 lines) | stat: -rw-r--r-- 18,090 bytes parent folder | download | duplicates (4)
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
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
//===-- sanitizer_symbolizer_posix_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.
// POSIX-specific implementation of symbolizer parts.
//===----------------------------------------------------------------------===//

#include "sanitizer_platform.h"
#if SANITIZER_POSIX
#include "sanitizer_allocator_internal.h"
#include "sanitizer_common.h"
#include "sanitizer_file.h"
#include "sanitizer_flags.h"
#include "sanitizer_internal_defs.h"
#include "sanitizer_linux.h"
#include "sanitizer_placement_new.h"
#include "sanitizer_posix.h"
#include "sanitizer_procmaps.h"
#include "sanitizer_symbolizer_internal.h"
#include "sanitizer_symbolizer_libbacktrace.h"
#include "sanitizer_symbolizer_mac.h"
#include "llvm/Config/llvm-config.h" // for LLVM_VERSION_MAJOR

#define TOSTR2(X) #X
#define TOSTR(X) TOSTR2(X)

#include <dlfcn.h>   // for dlsym()
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>

#if SANITIZER_MAC
#include <util.h>  // for forkpty()
#endif  // SANITIZER_MAC

// C++ demangling function, as required by Itanium C++ ABI. This is weak,
// because we do not require a C++ ABI library to be linked to a program
// using sanitizers; if it's not present, we'll just use the mangled name.
namespace __cxxabiv1 {
  extern "C" SANITIZER_WEAK_ATTRIBUTE
  char *__cxa_demangle(const char *mangled, char *buffer,
                                  size_t *length, int *status);
}

namespace __sanitizer {

// Attempts to demangle the name via __cxa_demangle from __cxxabiv1.
const char *DemangleCXXABI(const char *name) {
  // FIXME: __cxa_demangle aggressively insists on allocating memory.
  // There's not much we can do about that, short of providing our
  // own demangler (libc++abi's implementation could be adapted so that
  // it does not allocate). For now, we just call it anyway, and we leak
  // the returned value.
  if (&__cxxabiv1::__cxa_demangle)
    if (const char *demangled_name =
          __cxxabiv1::__cxa_demangle(name, 0, 0, 0))
      return demangled_name;

  return name;
}

// As of now, there are no headers for the Swift runtime. Once they are
// present, we will weakly link since we do not require Swift runtime to be
// linked.
typedef char *(*swift_demangle_ft)(const char *mangledName,
                                   size_t mangledNameLength, char *outputBuffer,
                                   size_t *outputBufferSize, uint32_t flags);
static swift_demangle_ft swift_demangle_f;

// This must not happen lazily at symbolication time, because dlsym uses
// malloc and thread-local storage, which is not a good thing to do during
// symbolication.
static void InitializeSwiftDemangler() {
  swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");
  (void)dlerror(); // Cleanup error message in case of failure
}

// Attempts to demangle a Swift name. The demangler will return nullptr if a
// non-Swift name is passed in.
const char *DemangleSwift(const char *name) {
  if (!name) return nullptr;

  // Check if we are dealing with a Swift mangled name first.
  if (name[0] != '_' || name[1] != 'T') {
    return nullptr;
  }

  if (swift_demangle_f)
    return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);

  return nullptr;
}

const char *DemangleSwiftAndCXX(const char *name) {
  if (!name) return nullptr;
  if (const char *swift_demangled_name = DemangleSwift(name))
    return swift_demangled_name;
  return DemangleCXXABI(name);
}

static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) {
  int *infd = NULL;
  int *outfd = NULL;
  // The client program may close its stdin and/or stdout and/or stderr
  // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
  // In this case the communication between the forked processes may be
  // broken if either the parent or the child tries to close or duplicate
  // these descriptors. The loop below produces two pairs of file
  // descriptors, each greater than 2 (stderr).
  int sock_pair[5][2];
  for (int i = 0; i < 5; i++) {
    if (pipe(sock_pair[i]) == -1) {
      for (int j = 0; j < i; j++) {
        internal_close(sock_pair[j][0]);
        internal_close(sock_pair[j][1]);
      }
      return false;
    } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
      if (infd == NULL) {
        infd = sock_pair[i];
      } else {
        outfd = sock_pair[i];
        for (int j = 0; j < i; j++) {
          if (sock_pair[j] == infd) continue;
          internal_close(sock_pair[j][0]);
          internal_close(sock_pair[j][1]);
        }
        break;
      }
    }
  }
  CHECK(infd);
  CHECK(outfd);
  infd_[0] = infd[0];
  infd_[1] = infd[1];
  outfd_[0] = outfd[0];
  outfd_[1] = outfd[1];
  return true;
}

bool SymbolizerProcess::StartSymbolizerSubprocess() {
  if (!FileExists(path_)) {
    if (!reported_invalid_path_) {
      Report("WARNING: invalid path to external symbolizer!\n");
      reported_invalid_path_ = true;
    }
    return false;
  }

  int pid = -1;

  int infd[2];
  internal_memset(&infd, 0, sizeof(infd));
  int outfd[2];
  internal_memset(&outfd, 0, sizeof(outfd));
  if (!CreateTwoHighNumberedPipes(infd, outfd)) {
    Report("WARNING: Can't create a socket pair to start "
           "external symbolizer (errno: %d)\n", errno);
    return false;
  }

  if (use_forkpty_) {
#if SANITIZER_MAC
    fd_t fd = kInvalidFd;

    // forkpty redirects stdout and stderr into a single stream, so we would
    // receive error messages as standard replies. To avoid that, let's dup
    // stderr and restore it in the child.
    int saved_stderr = dup(STDERR_FILENO);
    CHECK_GE(saved_stderr, 0);

    // We only need one pipe, for stdin of the child.
    close(outfd[0]);
    close(outfd[1]);

    // Use forkpty to disable buffering in the new terminal.
    pid = internal_forkpty(&fd);
    if (pid == -1) {
      // forkpty() failed.
      Report("WARNING: failed to fork external symbolizer (errno: %d)\n",
             errno);
      return false;
    } else if (pid == 0) {
      // Child subprocess.

      // infd[0] is the child's reading end.
      close(infd[1]);

      // Set up stdin to read from the pipe.
      CHECK_GE(dup2(infd[0], STDIN_FILENO), 0);
      close(infd[0]);

      // Restore stderr.
      CHECK_GE(dup2(saved_stderr, STDERR_FILENO), 0);
      close(saved_stderr);

      const char *argv[kArgVMax];
      GetArgV(path_, argv);
      execv(path_, const_cast<char **>(&argv[0]));
      internal__exit(1);
    }

    // Input for the child, infd[1] is our writing end.
    output_fd_ = infd[1];
    close(infd[0]);

    // Continue execution in parent process.
    input_fd_ = fd;

    close(saved_stderr);

    // Disable echo in the new terminal, disable CR.
    struct termios termflags;
    tcgetattr(fd, &termflags);
    termflags.c_oflag &= ~ONLCR;
    termflags.c_lflag &= ~ECHO;
    tcsetattr(fd, TCSANOW, &termflags);
#else  // SANITIZER_MAC
    UNIMPLEMENTED();
#endif  // SANITIZER_MAC
  } else {
    const char *argv[kArgVMax];
    GetArgV(path_, argv);
    pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
                          /* stdout */ infd[1]);
    if (pid < 0) {
      internal_close(infd[0]);
      internal_close(outfd[1]);
      return false;
    }

    input_fd_ = infd[0];
    output_fd_ = outfd[1];
  }

  CHECK_GT(pid, 0);

  // Check that symbolizer subprocess started successfully.
  SleepForMillis(kSymbolizerStartupTimeMillis);
  if (!IsProcessRunning(pid)) {
    // Either waitpid failed, or child has already exited.
    Report("WARNING: external symbolizer didn't start up correctly!\n");
    return false;
  }

  return true;
}

class Addr2LineProcess : public SymbolizerProcess {
 public:
  Addr2LineProcess(const char *path, const char *module_name)
      : SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {}

  const char *module_name() const { return module_name_; }

 private:
  void GetArgV(const char *path_to_binary,
               const char *(&argv)[kArgVMax]) const override {
    int i = 0;
    argv[i++] = path_to_binary;
    argv[i++] = "-iCfe";
    argv[i++] = module_name_;
    argv[i++] = nullptr;
  }

  bool ReachedEndOfOutput(const char *buffer, uptr length) const override;

  bool ReadFromSymbolizer(char *buffer, uptr max_length) override {
    if (!SymbolizerProcess::ReadFromSymbolizer(buffer, max_length))
      return false;
    // The returned buffer is empty when output is valid, but exceeds
    // max_length.
    if (*buffer == '\0')
      return true;
    // We should cut out output_terminator_ at the end of given buffer,
    // appended by addr2line to mark the end of its meaningful output.
    // We cannot scan buffer from it's beginning, because it is legal for it
    // to start with output_terminator_ in case given offset is invalid. So,
    // scanning from second character.
    char *garbage = internal_strstr(buffer + 1, output_terminator_);
    // This should never be NULL since buffer must end up with
    // output_terminator_.
    CHECK(garbage);
    // Trim the buffer.
    garbage[0] = '\0';
    return true;
  }

  const char *module_name_;  // Owned, leaked.
  static const char output_terminator_[];
};

const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n";

bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer,
                                          uptr length) const {
  const size_t kTerminatorLen = sizeof(output_terminator_) - 1;
  // Skip, if we read just kTerminatorLen bytes, because Addr2Line output
  // should consist at least of two pairs of lines:
  // 1. First one, corresponding to given offset to be symbolized
  // (may be equal to output_terminator_, if offset is not valid).
  // 2. Second one for output_terminator_, itself to mark the end of output.
  if (length <= kTerminatorLen) return false;
  // Addr2Line output should end up with output_terminator_.
  return !internal_memcmp(buffer + length - kTerminatorLen,
                          output_terminator_, kTerminatorLen);
}

class Addr2LinePool : public SymbolizerTool {
 public:
  explicit Addr2LinePool(const char *addr2line_path,
                         LowLevelAllocator *allocator)
      : addr2line_path_(addr2line_path), allocator_(allocator) {
    addr2line_pool_.reserve(16);
  }

  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
    if (const char *buf =
            SendCommand(stack->info.module, stack->info.module_offset)) {
      ParseSymbolizePCOutput(buf, stack);
      return true;
    }
    return false;
  }

  bool SymbolizeData(uptr addr, DataInfo *info) override {
    return false;
  }

 private:
  const char *SendCommand(const char *module_name, uptr module_offset) {
    Addr2LineProcess *addr2line = 0;
    for (uptr i = 0; i < addr2line_pool_.size(); ++i) {
      if (0 ==
          internal_strcmp(module_name, addr2line_pool_[i]->module_name())) {
        addr2line = addr2line_pool_[i];
        break;
      }
    }
    if (!addr2line) {
      addr2line =
          new(*allocator_) Addr2LineProcess(addr2line_path_, module_name);
      addr2line_pool_.push_back(addr2line);
    }
    CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name()));
    char buffer[kBufferSize];
    internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n",
                      module_offset, dummy_address_);
    return addr2line->SendCommand(buffer);
  }

  static const uptr kBufferSize = 64;
  const char *addr2line_path_;
  LowLevelAllocator *allocator_;
  InternalMmapVector<Addr2LineProcess*> addr2line_pool_;
  static const uptr dummy_address_ =
      FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX);
};

#if SANITIZER_SUPPORTS_WEAK_HOOKS
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
bool __sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset,
                                char *Buffer, int MaxLength);
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
bool __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,
                                char *Buffer, int MaxLength);
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
void __sanitizer_symbolize_flush();
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
int __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
                                   int MaxLength);
}  // extern "C"

class InternalSymbolizer : public SymbolizerTool {
 public:
  static InternalSymbolizer *get(LowLevelAllocator *alloc) {
    if (__sanitizer_symbolize_code != 0 &&
        __sanitizer_symbolize_data != 0) {
      return new(*alloc) InternalSymbolizer();
    }
    return 0;
  }

  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
    bool result = __sanitizer_symbolize_code(
        stack->info.module, stack->info.module_offset, buffer_, kBufferSize);
    if (result) ParseSymbolizePCOutput(buffer_, stack);
    return result;
  }

  bool SymbolizeData(uptr addr, DataInfo *info) override {
    bool result = __sanitizer_symbolize_data(info->module, info->module_offset,
                                             buffer_, kBufferSize);
    if (result) {
      ParseSymbolizeDataOutput(buffer_, info);
      info->start += (addr - info->module_offset);  // Add the base address.
    }
    return result;
  }

  void Flush() override {
    if (__sanitizer_symbolize_flush)
      __sanitizer_symbolize_flush();
  }

  const char *Demangle(const char *name) override {
    if (__sanitizer_symbolize_demangle) {
      for (uptr res_length = 1024;
           res_length <= InternalSizeClassMap::kMaxSize;) {
        char *res_buff = static_cast<char*>(InternalAlloc(res_length));
        uptr req_length =
            __sanitizer_symbolize_demangle(name, res_buff, res_length);
        if (req_length > res_length) {
          res_length = req_length + 1;
          InternalFree(res_buff);
          continue;
        }
        return res_buff;
      }
    }
    return name;
  }

 private:
  InternalSymbolizer() { }

  static const int kBufferSize = 16 * 1024;
  char buffer_[kBufferSize];
};
#else  // SANITIZER_SUPPORTS_WEAK_HOOKS

class InternalSymbolizer : public SymbolizerTool {
 public:
  static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; }
};

#endif  // SANITIZER_SUPPORTS_WEAK_HOOKS

const char *Symbolizer::PlatformDemangle(const char *name) {
  return DemangleSwiftAndCXX(name);
}

static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
  const char *path = common_flags()->external_symbolizer_path;
  const char *binary_name = path ? StripModuleName(path) : "";
  if (path && path[0] == '\0') {
    VReport(2, "External symbolizer is explicitly disabled.\n");
    return nullptr;
  } else if (!internal_strcmp(binary_name, "llvm-symbolizer")) {
    VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path);
    return new(*allocator) LLVMSymbolizer(path, allocator);
  } else if (!internal_strcmp(binary_name, "atos")) {
#if SANITIZER_MAC
    VReport(2, "Using atos at user-specified path: %s\n", path);
    return new(*allocator) AtosSymbolizer(path, allocator);
#else  // SANITIZER_MAC
    Report("ERROR: Using `atos` is only supported on Darwin.\n");
    Die();
#endif  // SANITIZER_MAC
  } else if (!internal_strcmp(binary_name, "addr2line")) {
    VReport(2, "Using addr2line at user-specified path: %s\n", path);
    return new(*allocator) Addr2LinePool(path, allocator);
  } else if (path) {
    Report("ERROR: External symbolizer path is set to '%s' which isn't "
           "a known symbolizer. Please set the path to the llvm-symbolizer "
           "binary or other known tool.\n", path);
    Die();
  }

  // Otherwise symbolizer program is unknown, let's search $PATH
  CHECK(path == nullptr);
#if SANITIZER_MAC
  if (const char *found_path = FindPathToBinary("atos")) {
    VReport(2, "Using atos found at: %s\n", found_path);
    return new(*allocator) AtosSymbolizer(found_path, allocator);
  }
#endif  // SANITIZER_MAC
  if (const char *found_path = "/usr/bin/llvm-symbolizer-" TOSTR(LLVM_VERSION_MAJOR)) {
    VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
    return new(*allocator) LLVMSymbolizer(found_path, allocator);
  }
  if (common_flags()->allow_addr2line) {
    if (const char *found_path = FindPathToBinary("addr2line")) {
      VReport(2, "Using addr2line found at: %s\n", found_path);
      return new(*allocator) Addr2LinePool(found_path, allocator);
    }
  }
  return nullptr;
}

static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
                                  LowLevelAllocator *allocator) {
  if (!common_flags()->symbolize) {
    VReport(2, "Symbolizer is disabled.\n");
    return;
  }
  if (IsAllocatorOutOfMemory()) {
    VReport(2, "Cannot use internal symbolizer: out of memory\n");
  } else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {
    VReport(2, "Using internal symbolizer.\n");
    list->push_back(tool);
    return;
  }
  if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) {
    VReport(2, "Using libbacktrace symbolizer.\n");
    list->push_back(tool);
    return;
  }

  if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) {
    list->push_back(tool);
  }

#if SANITIZER_MAC
  VReport(2, "Using dladdr symbolizer.\n");
  list->push_back(new(*allocator) DlAddrSymbolizer());
#endif  // SANITIZER_MAC
}

Symbolizer *Symbolizer::PlatformInit() {
  IntrusiveList<SymbolizerTool> list;
  list.clear();
  ChooseSymbolizerTools(&list, &symbolizer_allocator_);
  return new(symbolizer_allocator_) Symbolizer(list);
}

void Symbolizer::LateInitialize() {
  Symbolizer::GetOrInit();
  InitializeSwiftDemangler();
}

}  // namespace __sanitizer

#endif  // SANITIZER_POSIX