aboutsummaryrefslogtreecommitdiff
path: root/src/client/windows/handler/exception_handler.cc
blob: c42718cb770b0567e068a3751ccaa0bd76f3df2b (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
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
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
// Copyright (c) 2006, 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.

#include <objbase.h>

#include <algorithm>
#include <cassert>
#include <cstdio>

#include "common/windows/string_utils-inl.h"

#include "client/windows/common/ipc_protocol.h"
#include "client/windows/handler/exception_handler.h"
#include "common/windows/guid_string.h"

namespace google_breakpad {

// This is passed as the context to the MinidumpWriteDump callback.
typedef struct {
  AppMemoryList::const_iterator iter;
  AppMemoryList::const_iterator end;
} MinidumpCallbackContext;

// This define is new to Windows 10.
#ifndef DBG_PRINTEXCEPTION_WIDE_C
#define DBG_PRINTEXCEPTION_WIDE_C ((DWORD)0x4001000A)
#endif

vector<ExceptionHandler*>* ExceptionHandler::handler_stack_ = NULL;
LONG ExceptionHandler::handler_stack_index_ = 0;
CRITICAL_SECTION ExceptionHandler::handler_stack_critical_section_;
volatile LONG ExceptionHandler::instance_count_ = 0;

ExceptionHandler::ExceptionHandler(const wstring& dump_path,
                                   FilterCallback filter,
                                   MinidumpCallback callback,
                                   void* callback_context,
                                   int handler_types,
                                   MINIDUMP_TYPE dump_type,
                                   const wchar_t* pipe_name,
                                   const CustomClientInfo* custom_info) {
  Initialize(dump_path,
             filter,
             callback,
             callback_context,
             handler_types,
             dump_type,
             pipe_name,
             NULL,  // pipe_handle
             NULL,  // crash_generation_client
             custom_info);
}

ExceptionHandler::ExceptionHandler(const wstring& dump_path,
                                   FilterCallback filter,
                                   MinidumpCallback callback,
                                   void* callback_context,
                                   int handler_types,
                                   MINIDUMP_TYPE dump_type,
                                   HANDLE pipe_handle,
                                   const CustomClientInfo* custom_info) {
  Initialize(dump_path,
             filter,
             callback,
             callback_context,
             handler_types,
             dump_type,
             NULL,  // pipe_name
             pipe_handle,
             NULL,  // crash_generation_client
             custom_info);
}

ExceptionHandler::ExceptionHandler(
    const wstring& dump_path,
    FilterCallback filter,
    MinidumpCallback callback,
    void* callback_context,
    int handler_types,
    CrashGenerationClient* crash_generation_client) {
  // The dump_type, pipe_name and custom_info that are passed in to Initialize()
  // are not used.  The ones set in crash_generation_client are used instead.
  Initialize(dump_path,
             filter,
             callback,
             callback_context,
             handler_types,
             MiniDumpNormal,           // dump_type - not used
             NULL,                     // pipe_name - not used
             NULL,                     // pipe_handle
             crash_generation_client,
             NULL);                    // custom_info - not used
}

ExceptionHandler::ExceptionHandler(const wstring &dump_path,
                                   FilterCallback filter,
                                   MinidumpCallback callback,
                                   void* callback_context,
                                   int handler_types) {
  Initialize(dump_path,
             filter,
             callback,
             callback_context,
             handler_types,
             MiniDumpNormal,
             NULL,   // pipe_name
             NULL,   // pipe_handle
             NULL,   // crash_generation_client
             NULL);  // custom_info
}

void ExceptionHandler::Initialize(
    const wstring& dump_path,
    FilterCallback filter,
    MinidumpCallback callback,
    void* callback_context,
    int handler_types,
    MINIDUMP_TYPE dump_type,
    const wchar_t* pipe_name,
    HANDLE pipe_handle,
    CrashGenerationClient* crash_generation_client,
    const CustomClientInfo* custom_info) {
  LONG instance_count = InterlockedIncrement(&instance_count_);
  filter_ = filter;
  callback_ = callback;
  callback_context_ = callback_context;
  dump_path_c_ = NULL;
  next_minidump_id_c_ = NULL;
  next_minidump_path_c_ = NULL;
  dbghelp_module_ = NULL;
  minidump_write_dump_ = NULL;
  dump_type_ = dump_type;
  rpcrt4_module_ = NULL;
  uuid_create_ = NULL;
  handler_types_ = handler_types;
  previous_filter_ = NULL;
#if _MSC_VER >= 1400  // MSVC 2005/8
  previous_iph_ = NULL;
#endif  // _MSC_VER >= 1400
  previous_pch_ = NULL;
  handler_thread_ = NULL;
  is_shutdown_ = false;
  handler_start_semaphore_ = NULL;
  handler_finish_semaphore_ = NULL;
  requesting_thread_id_ = 0;
  exception_info_ = NULL;
  assertion_ = NULL;
  handler_return_value_ = false;
  handle_debug_exceptions_ = false;
  consume_invalid_handle_exceptions_ = false;

  // Attempt to use out-of-process if user has specified a pipe or a
  // crash generation client.
  scoped_ptr<CrashGenerationClient> client;
  if (crash_generation_client) {
    client.reset(crash_generation_client);
  } else if (pipe_name) {
    client.reset(
      new CrashGenerationClient(pipe_name, dump_type_, custom_info));
  } else if (pipe_handle) {
    client.reset(
      new CrashGenerationClient(pipe_handle, dump_type_, custom_info));
  }

  if (client.get() != NULL) {
    // If successful in registering with the monitoring process,
    // there is no need to setup in-process crash generation.
    if (client->Register()) {
      crash_generation_client_.reset(client.release());
    }
  }

  if (!IsOutOfProcess()) {
    // Either client did not ask for out-of-process crash generation
    // or registration with the server process failed. In either case,
    // setup to do in-process crash generation.

    // Set synchronization primitives and the handler thread.  Each
    // ExceptionHandler object gets its own handler thread because that's the
    // only way to reliably guarantee sufficient stack space in an exception,
    // and it allows an easy way to get a snapshot of the requesting thread's
    // context outside of an exception.
    InitializeCriticalSection(&handler_critical_section_);
    handler_start_semaphore_ = CreateSemaphore(NULL, 0, 1, NULL);
    assert(handler_start_semaphore_ != NULL);

    handler_finish_semaphore_ = CreateSemaphore(NULL, 0, 1, NULL);
    assert(handler_finish_semaphore_ != NULL);

    // Don't attempt to create the thread if we could not create the semaphores.
    if (handler_finish_semaphore_ != NULL && handler_start_semaphore_ != NULL) {
      DWORD thread_id;
      const int kExceptionHandlerThreadInitialStackSize = 64 * 1024;
      handler_thread_ = CreateThread(NULL,         // lpThreadAttributes
                                     kExceptionHandlerThreadInitialStackSize,
                                     ExceptionHandlerThreadMain,
                                     this,         // lpParameter
                                     0,            // dwCreationFlags
                                     &thread_id);
      assert(handler_thread_ != NULL);
    }

    dbghelp_module_ = LoadLibrary(L"dbghelp.dll");
    if (dbghelp_module_) {
      minidump_write_dump_ = reinterpret_cast<MiniDumpWriteDump_type>(
          GetProcAddress(dbghelp_module_, "MiniDumpWriteDump"));
    }

    // Load this library dynamically to not affect existing projects.  Most
    // projects don't link against this directly, it's usually dynamically
    // loaded by dependent code.
    rpcrt4_module_ = LoadLibrary(L"rpcrt4.dll");
    if (rpcrt4_module_) {
      uuid_create_ = reinterpret_cast<UuidCreate_type>(
          GetProcAddress(rpcrt4_module_, "UuidCreate"));
    }

    // set_dump_path calls UpdateNextID.  This sets up all of the path and id
    // strings, and their equivalent c_str pointers.
    set_dump_path(dump_path);
  }

  // Reserve one element for the instruction memory
  AppMemory instruction_memory;
  instruction_memory.ptr = NULL;
  instruction_memory.length = 0;
  app_memory_info_.push_back(instruction_memory);

  // There is a race condition here. If the first instance has not yet
  // initialized the critical section, the second (and later) instances may
  // try to use uninitialized critical section object. The feature of multiple
  // instances in one module is not used much, so leave it as is for now.
  // One way to solve this in the current design (that is, keeping the static
  // handler stack) is to use spin locks with volatile bools to synchronize
  // the handler stack. This works only if the compiler guarantees to generate
  // cache coherent code for volatile.
  // TODO(munjal): Fix this in a better way by changing the design if possible.

  // Lazy initialization of the handler_stack_critical_section_
  if (instance_count == 1) {
    InitializeCriticalSection(&handler_stack_critical_section_);
  }

  if (handler_types != HANDLER_NONE) {
    EnterCriticalSection(&handler_stack_critical_section_);

    // The first time an ExceptionHandler that installs a handler is
    // created, set up the handler stack.
    if (!handler_stack_) {
      handler_stack_ = new vector<ExceptionHandler*>();
    }
    handler_stack_->push_back(this);

    if (handler_types & HANDLER_EXCEPTION)
      previous_filter_ = SetUnhandledExceptionFilter(HandleException);

#if _MSC_VER >= 1400  // MSVC 2005/8
    if (handler_types & HANDLER_INVALID_PARAMETER)
      previous_iph_ = _set_invalid_parameter_handler(HandleInvalidParameter);
#endif  // _MSC_VER >= 1400

    if (handler_types & HANDLER_PURECALL)
      previous_pch_ = _set_purecall_handler(HandlePureVirtualCall);

    LeaveCriticalSection(&handler_stack_critical_section_);
  }
}

ExceptionHandler::~ExceptionHandler() {
  if (dbghelp_module_) {
    FreeLibrary(dbghelp_module_);
  }

  if (rpcrt4_module_) {
    FreeLibrary(rpcrt4_module_);
  }

  if (handler_types_ != HANDLER_NONE) {
    EnterCriticalSection(&handler_stack_critical_section_);

    if (handler_types_ & HANDLER_EXCEPTION)
      SetUnhandledExceptionFilter(previous_filter_);

#if _MSC_VER >= 1400  // MSVC 2005/8
    if (handler_types_ & HANDLER_INVALID_PARAMETER)
      _set_invalid_parameter_handler(previous_iph_);
#endif  // _MSC_VER >= 1400

    if (handler_types_ & HANDLER_PURECALL)
      _set_purecall_handler(previous_pch_);

    if (handler_stack_->back() == this) {
      handler_stack_->pop_back();
    } else {
      // TODO(mmentovai): use advapi32!ReportEvent to log the warning to the
      // system's application event log.
      fprintf(stderr, "warning: removing Breakpad handler out of order\n");
      vector<ExceptionHandler*>::iterator iterator = handler_stack_->begin();
      while (iterator != handler_stack_->end()) {
        if (*iterator == this) {
          iterator = handler_stack_->erase(iterator);
        } else {
          ++iterator;
        }
      }
    }

    if (handler_stack_->empty()) {
      // When destroying the last ExceptionHandler that installed a handler,
      // clean up the handler stack.
      delete handler_stack_;
      handler_stack_ = NULL;
    }

    LeaveCriticalSection(&handler_stack_critical_section_);
  }

  // Some of the objects were only initialized if out of process
  // registration was not done.
  if (!IsOutOfProcess()) {
#ifdef BREAKPAD_NO_TERMINATE_THREAD
    // Clean up the handler thread and synchronization primitives. The handler
    // thread is either waiting on the semaphore to handle a crash or it is
    // handling a crash. Coming out of the wait is fast but wait more in the
    // eventuality a crash is handled.  This compilation option results in a
    // deadlock if the exception handler is destroyed while executing code
    // inside DllMain.
    is_shutdown_ = true;
    ReleaseSemaphore(handler_start_semaphore_, 1, NULL);
    const int kWaitForHandlerThreadMs = 60000;
    WaitForSingleObject(handler_thread_, kWaitForHandlerThreadMs);
#else
    TerminateThread(handler_thread_, 1);
#endif  // BREAKPAD_NO_TERMINATE_THREAD

    CloseHandle(handler_thread_);
    handler_thread_ = NULL;
    DeleteCriticalSection(&handler_critical_section_);
    CloseHandle(handler_start_semaphore_);
    CloseHandle(handler_finish_semaphore_);
  }

  // There is a race condition in the code below: if this instance is
  // deleting the static critical section and a new instance of the class
  // is created, then there is a possibility that the critical section be
  // initialized while the same critical section is being deleted. Given the
  // usage pattern for the code, this race condition is unlikely to hit, but it
  // is a race condition nonetheless.
  if (InterlockedDecrement(&instance_count_) == 0) {
    DeleteCriticalSection(&handler_stack_critical_section_);
  }
}

bool ExceptionHandler::RequestUpload(DWORD crash_id) {
  return crash_generation_client_->RequestUpload(crash_id);
}

// static
DWORD ExceptionHandler::ExceptionHandlerThreadMain(void* lpParameter) {
  ExceptionHandler* self = reinterpret_cast<ExceptionHandler *>(lpParameter);
  assert(self);
  assert(self->handler_start_semaphore_ != NULL);
  assert(self->handler_finish_semaphore_ != NULL);

  while (true) {
    if (WaitForSingleObject(self->handler_start_semaphore_, INFINITE) ==
        WAIT_OBJECT_0) {
      // Perform the requested action.
      if (self->is_shutdown_) {
        // The instance of the exception handler is being destroyed.
        break;
      } else {
        self->handler_return_value_ =
            self->WriteMinidumpWithException(self->requesting_thread_id_,
                                             self->exception_info_,
                                             self->assertion_);
      }

      // Allow the requesting thread to proceed.
      ReleaseSemaphore(self->handler_finish_semaphore_, 1, NULL);
    }
  }

  // This statement is not reached when the thread is unconditionally
  // terminated by the ExceptionHandler destructor.
  return 0;
}

// HandleException and HandleInvalidParameter must create an
// AutoExceptionHandler object to maintain static state and to determine which
// ExceptionHandler instance to use.  The constructor locates the correct
// instance, and makes it available through get_handler().  The destructor
// restores the state in effect prior to allocating the AutoExceptionHandler.
class AutoExceptionHandler {
 public:
  AutoExceptionHandler() {
    // Increment handler_stack_index_ so that if another Breakpad handler is
    // registered using this same HandleException function, and it needs to be
    // called while this handler is running (either because this handler
    // declines to handle the exception, or an exception occurs during
    // handling), HandleException will find the appropriate ExceptionHandler
    // object in handler_stack_ to deliver the exception to.
    //
    // Because handler_stack_ is addressed in reverse (as |size - index|),
    // preincrementing handler_stack_index_ avoids needing to subtract 1 from
    // the argument to |at|.
    //
    // The index is maintained instead of popping elements off of the handler
    // stack and pushing them at the end of this method.  This avoids ruining
    // the order of elements in the stack in the event that some other thread
    // decides to manipulate the handler stack (such as creating a new
    // ExceptionHandler object) while an exception is being handled.
    EnterCriticalSection(&ExceptionHandler::handler_stack_critical_section_);
    handler_ = ExceptionHandler::handler_stack_->at(
        ExceptionHandler::handler_stack_->size() -
        ++ExceptionHandler::handler_stack_index_);

    // In case another exception occurs while this handler is doing its thing,
    // it should be delivered to the previous filter.
    SetUnhandledExceptionFilter(handler_->previous_filter_);
#if _MSC_VER >= 1400  // MSVC 2005/8
    _set_invalid_parameter_handler(handler_->previous_iph_);
#endif  // _MSC_VER >= 1400
    _set_purecall_handler(handler_->previous_pch_);
  }

  ~AutoExceptionHandler() {
    // Put things back the way they were before entering this handler.
    SetUnhandledExceptionFilter(ExceptionHandler::HandleException);
#if _MSC_VER >= 1400  // MSVC 2005/8
    _set_invalid_parameter_handler(ExceptionHandler::HandleInvalidParameter);
#endif  // _MSC_VER >= 1400
    _set_purecall_handler(ExceptionHandler::HandlePureVirtualCall);

    --ExceptionHandler::handler_stack_index_;
    LeaveCriticalSection(&ExceptionHandler::handler_stack_critical_section_);
  }

  ExceptionHandler* get_handler() const { return handler_; }

 private:
  ExceptionHandler* handler_;
};

// static
LONG ExceptionHandler::HandleException(EXCEPTION_POINTERS* exinfo) {
  AutoExceptionHandler auto_exception_handler;
  ExceptionHandler* current_handler = auto_exception_handler.get_handler();

  // Ignore EXCEPTION_BREAKPOINT and EXCEPTION_SINGLE_STEP exceptions.  This
  // logic will short-circuit before calling WriteMinidumpOnHandlerThread,
  // allowing something else to handle the breakpoint without incurring the
  // overhead transitioning to and from the handler thread.  This behavior
  // can be overridden by calling ExceptionHandler::set_handle_debug_exceptions.
  DWORD code = exinfo->ExceptionRecord->ExceptionCode;
  LONG action;
  bool is_debug_exception = (code == EXCEPTION_BREAKPOINT) ||
                            (code == EXCEPTION_SINGLE_STEP) ||
                            (code == DBG_PRINTEXCEPTION_C) ||
                            (code == DBG_PRINTEXCEPTION_WIDE_C);

  if (code == EXCEPTION_INVALID_HANDLE &&
      current_handler->consume_invalid_handle_exceptions_) {
    return EXCEPTION_CONTINUE_EXECUTION;
  }

  bool success = false;

  if (!is_debug_exception ||
      current_handler->get_handle_debug_exceptions()) {
    // If out-of-proc crash handler client is available, we have to use that
    // to generate dump and we cannot fall back on in-proc dump generation
    // because we never prepared for an in-proc dump generation

    // In case of out-of-process dump generation, directly call
    // WriteMinidumpWithException since there is no separate thread running.
    if (current_handler->IsOutOfProcess()) {
      success = current_handler->WriteMinidumpWithException(
          GetCurrentThreadId(),
          exinfo,
          NULL);
    } else {
      success = current_handler->WriteMinidumpOnHandlerThread(exinfo, NULL);
    }
  }

  // The handler fully handled the exception.  Returning
  // EXCEPTION_EXECUTE_HANDLER indicates this to the system, and usually
  // results in the application being terminated.
  //
  // Note: If the application was launched from within the Cygwin
  // environment, returning EXCEPTION_EXECUTE_HANDLER seems to cause the
  // application to be restarted.
  if (success) {
    action = EXCEPTION_EXECUTE_HANDLER;
  } else {
    // There was an exception, it was a breakpoint or something else ignored
    // above, or it was passed to the handler, which decided not to handle it.
    // This could be because the filter callback didn't want it, because
    // minidump writing failed for some reason, or because the post-minidump
    // callback function indicated failure.  Give the previous handler a
    // chance to do something with the exception.  If there is no previous
    // handler, return EXCEPTION_CONTINUE_SEARCH, which will allow a debugger
    // or native "crashed" dialog to handle the exception.
    if (current_handler->previous_filter_) {
      action = current_handler->previous_filter_(exinfo);
    } else {
      action = EXCEPTION_CONTINUE_SEARCH;
    }
  }

  return action;
}

#if _MSC_VER >= 1400  // MSVC 2005/8
// static
void ExceptionHandler::HandleInvalidParameter(const wchar_t* expression,
                                              const wchar_t* function,
                                              const wchar_t* file,
                                              unsigned int line,
                                              uintptr_t reserved) {
  // This is an invalid parameter, not an exception.  It's safe to play with
  // sprintf here.
  AutoExceptionHandler auto_exception_handler;
  ExceptionHandler* current_handler = auto_exception_handler.get_handler();

  MDRawAssertionInfo assertion;
  memset(&assertion, 0, sizeof(assertion));
  _snwprintf_s(reinterpret_cast<wchar_t*>(assertion.expression),
               sizeof(assertion.expression) / sizeof(assertion.expression[0]),
               _TRUNCATE, L"%s", expression);
  _snwprintf_s(reinterpret_cast<wchar_t*>(assertion.function),
               sizeof(assertion.function) / sizeof(assertion.function[0]),
               _TRUNCATE, L"%s", function);
  _snwprintf_s(reinterpret_cast<wchar_t*>(assertion.file),
               sizeof(assertion.file) / sizeof(assertion.file[0]),
               _TRUNCATE, L"%s", file);
  assertion.line = line;
  assertion.type = MD_ASSERTION_INFO_TYPE_INVALID_PARAMETER;

  // Make up an exception record for the current thread and CPU context
  // to make it possible for the crash processor to classify these
  // as do regular crashes, and to make it humane for developers to
  // analyze them.
  EXCEPTION_RECORD exception_record = {};
  CONTEXT exception_context = {};
  EXCEPTION_POINTERS exception_ptrs = { &exception_record, &exception_context };

  ::RtlCaptureContext(&exception_context);

  exception_record.ExceptionCode = STATUS_INVALID_PARAMETER;

  // We store pointers to the the expression and function strings,
  // and the line as exception parameters to make them easy to
  // access by the developer on the far side.
  exception_record.NumberParameters = 3;
  exception_record.ExceptionInformation[0] =
      reinterpret_cast<ULONG_PTR>(&assertion.expression);
  exception_record.ExceptionInformation[1] =
      reinterpret_cast<ULONG_PTR>(&assertion.file);
  exception_record.ExceptionInformation[2] = assertion.line;

  bool success = false;
  // In case of out-of-process dump generation, directly call
  // WriteMinidumpWithException since there is no separate thread running.
  if (current_handler->IsOutOfProcess()) {
    success = current_handler->WriteMinidumpWithException(
        GetCurrentThreadId(),
        &exception_ptrs,
        &assertion);
  } else {
    success = current_handler->WriteMinidumpOnHandlerThread(&exception_ptrs,
                                                            &assertion);
  }

  if (!success) {
    if (current_handler->previous_iph_) {
      // The handler didn't fully handle the exception.  Give it to the
      // previous invalid parameter handler.
      current_handler->previous_iph_(expression,
                                     function,
                                     file,
                                     line,
                                     reserved);
    } else {
      // If there's no previous handler, pass the exception back in to the
      // invalid parameter handler's core.  That's the routine that called this
      // function, but now, since this function is no longer registered (and in
      // fact, no function at all is registered), this will result in the
      // default code path being taken: _CRT_DEBUGGER_HOOK and _invoke_watson.
      // Use _invalid_parameter where it exists (in _DEBUG builds) as it passes
      // more information through.  In non-debug builds, it is not available,
      // so fall back to using _invalid_parameter_noinfo.  See invarg.c in the
      // CRT source.
#ifdef _DEBUG
      _invalid_parameter(expression, function, file, line, reserved);
#else  // _DEBUG
      _invalid_parameter_noinfo();
#endif  // _DEBUG
    }
  }

  // The handler either took care of the invalid parameter problem itself,
  // or passed it on to another handler.  "Swallow" it by exiting, paralleling
  // the behavior of "swallowing" exceptions.
  exit(0);
}
#endif  // _MSC_VER >= 1400

// static
void ExceptionHandler::HandlePureVirtualCall() {
  // This is an pure virtual function call, not an exception.  It's safe to
  // play with sprintf here.
  AutoExceptionHandler auto_exception_handler;
  ExceptionHandler* current_handler = auto_exception_handler.get_handler();

  MDRawAssertionInfo assertion;
  memset(&assertion, 0, sizeof(assertion));
  assertion.type = MD_ASSERTION_INFO_TYPE_PURE_VIRTUAL_CALL;

  // Make up an exception record for the current thread and CPU context
  // to make it possible for the crash processor to classify these
  // as do regular crashes, and to make it humane for developers to
  // analyze them.
  EXCEPTION_RECORD exception_record = {};
  CONTEXT exception_context = {};
  EXCEPTION_POINTERS exception_ptrs = { &exception_record, &exception_context };

  ::RtlCaptureContext(&exception_context);

  exception_record.ExceptionCode = STATUS_NONCONTINUABLE_EXCEPTION;

  // We store pointers to the the expression and function strings,
  // and the line as exception parameters to make them easy to
  // access by the developer on the far side.
  exception_record.NumberParameters = 3;
  exception_record.ExceptionInformation[0] =
      reinterpret_cast<ULONG_PTR>(&assertion.expression);
  exception_record.ExceptionInformation[1] =
      reinterpret_cast<ULONG_PTR>(&assertion.file);
  exception_record.ExceptionInformation[2] = assertion.line;

  bool success = false;
  // In case of out-of-process dump generation, directly call
  // WriteMinidumpWithException since there is no separate thread running.

  if (current_handler->IsOutOfProcess()) {
    success = current_handler->WriteMinidumpWithException(
        GetCurrentThreadId(),
        &exception_ptrs,
        &assertion);
  } else {
    success = current_handler->WriteMinidumpOnHandlerThread(&exception_ptrs,
                                                            &assertion);
  }

  if (!success) {
    if (current_handler->previous_pch_) {
      // The handler didn't fully handle the exception.  Give it to the
      // previous purecall handler.
      current_handler->previous_pch_();
    } else {
      // If there's no previous handler, return and let _purecall handle it.
      // This will just put up an assertion dialog.
      return;
    }
  }

  // The handler either took care of the invalid parameter problem itself,
  // or passed it on to another handler.  "Swallow" it by exiting, paralleling
  // the behavior of "swallowing" exceptions.
  exit(0);
}

bool ExceptionHandler::WriteMinidumpOnHandlerThread(
    EXCEPTION_POINTERS* exinfo, MDRawAssertionInfo* assertion) {
  EnterCriticalSection(&handler_critical_section_);

  // There isn't much we can do if the handler thread
  // was not successfully created.
  if (handler_thread_ == NULL) {
    LeaveCriticalSection(&handler_critical_section_);
    return false;
  }

  // The handler thread should only be created when the semaphores are valid.
  assert(handler_start_semaphore_ != NULL);
  assert(handler_finish_semaphore_ != NULL);

  // Set up data to be passed in to the handler thread.
  requesting_thread_id_ = GetCurrentThreadId();
  exception_info_ = exinfo;
  assertion_ = assertion;

  // This causes the handler thread to call WriteMinidumpWithException.
  ReleaseSemaphore(handler_start_semaphore_, 1, NULL);

  // Wait until WriteMinidumpWithException is done and collect its return value.
  WaitForSingleObject(handler_finish_semaphore_, INFINITE);
  bool status = handler_return_value_;

  // Clean up.
  requesting_thread_id_ = 0;
  exception_info_ = NULL;
  assertion_ = NULL;

  LeaveCriticalSection(&handler_critical_section_);

  return status;
}

bool ExceptionHandler::WriteMinidump() {
  // Make up an exception record for the current thread and CPU context
  // to make it possible for the crash processor to classify these
  // as do regular crashes, and to make it humane for developers to
  // analyze them.
  EXCEPTION_RECORD exception_record = {};
  CONTEXT exception_context = {};
  EXCEPTION_POINTERS exception_ptrs = { &exception_record, &exception_context };

  ::RtlCaptureContext(&exception_context);
  exception_record.ExceptionCode = STATUS_NONCONTINUABLE_EXCEPTION;

  return WriteMinidumpForException(&exception_ptrs);
}

bool ExceptionHandler::WriteMinidumpForException(EXCEPTION_POINTERS* exinfo) {
  // In case of out-of-process dump generation, directly call
  // WriteMinidumpWithException since there is no separate thread running.
  if (IsOutOfProcess()) {
    return WriteMinidumpWithException(GetCurrentThreadId(),
                                      exinfo,
                                      NULL);
  }

  bool success = WriteMinidumpOnHandlerThread(exinfo, NULL);
  UpdateNextID();
  return success;
}

// static
bool ExceptionHandler::WriteMinidump(const wstring &dump_path,
                                     MinidumpCallback callback,
                                     void* callback_context,
                                     MINIDUMP_TYPE dump_type) {
  ExceptionHandler handler(dump_path, NULL, callback, callback_context,
                           HANDLER_NONE, dump_type, (HANDLE)NULL, NULL);
  return handler.WriteMinidump();
}

// static
bool ExceptionHandler::WriteMinidumpForChild(HANDLE child,
                                             DWORD child_blamed_thread,
                                             const wstring& dump_path,
                                             MinidumpCallback callback,
                                             void* callback_context,
                                             MINIDUMP_TYPE dump_type) {
  EXCEPTION_RECORD ex;
  CONTEXT ctx;
  EXCEPTION_POINTERS exinfo = { NULL, NULL };
  // As documented on MSDN, on failure SuspendThread returns (DWORD) -1
  const DWORD kFailedToSuspendThread = static_cast<DWORD>(-1);
  DWORD last_suspend_count = kFailedToSuspendThread;
  HANDLE child_thread_handle = OpenThread(THREAD_GET_CONTEXT |
                                          THREAD_QUERY_INFORMATION |
                                          THREAD_SUSPEND_RESUME,
                                          FALSE,
                                          child_blamed_thread);
  // This thread may have died already, so not opening the handle is a
  // non-fatal error.
  if (child_thread_handle != NULL) {
    last_suspend_count = SuspendThread(child_thread_handle);
    if (last_suspend_count != kFailedToSuspendThread) {
      ctx.ContextFlags = CONTEXT_ALL;
      if (GetThreadContext(child_thread_handle, &ctx)) {
        memset(&ex, 0, sizeof(ex));
        ex.ExceptionCode = EXCEPTION_BREAKPOINT;
#if defined(_M_IX86)
        ex.ExceptionAddress = reinterpret_cast<PVOID>(ctx.Eip);
#elif defined(_M_X64)
        ex.ExceptionAddress = reinterpret_cast<PVOID>(ctx.Rip);
#endif
        exinfo.ExceptionRecord = &ex;
        exinfo.ContextRecord = &ctx;
      }
    }
  }

  ExceptionHandler handler(dump_path, NULL, callback, callback_context,
                           HANDLER_NONE, dump_type, (HANDLE)NULL, NULL);
  bool success = handler.WriteMinidumpWithExceptionForProcess(
      child_blamed_thread,
      exinfo.ExceptionRecord ? &exinfo : NULL,
      NULL, child, false);

  if (last_suspend_count != kFailedToSuspendThread) {
    ResumeThread(child_thread_handle);
  }

  CloseHandle(child_thread_handle);

  if (callback) {
    success = callback(handler.dump_path_c_, handler.next_minidump_id_c_,
                       callback_context, NULL, NULL, success);
  }

  return success;
}

bool ExceptionHandler::WriteMinidumpWithException(
    DWORD requesting_thread_id,
    EXCEPTION_POINTERS* exinfo,
    MDRawAssertionInfo* assertion) {
  // Give user code a chance to approve or prevent writing a minidump.  If the
  // filter returns false, don't handle the exception at all.  If this method
  // was called as a result of an exception, returning false will cause
  // HandleException to call any previous handler or return
  // EXCEPTION_CONTINUE_SEARCH on the exception thread, allowing it to appear
  // as though this handler were not present at all.
  if (filter_ && !filter_(callback_context_, exinfo, assertion)) {
    return false;
  }

  bool success = false;
  if (IsOutOfProcess()) {
    success = crash_generation_client_->RequestDump(exinfo, assertion);
  } else {
    success = WriteMinidumpWithExceptionForProcess(requesting_thread_id,
                                                   exinfo,
                                                   assertion,
                                                   GetCurrentProcess(),
                                                   true);
  }

  if (callback_) {
    // TODO(munjal): In case of out-of-process dump generation, both
    // dump_path_c_ and next_minidump_id_ will be NULL. For out-of-process
    // scenario, the server process ends up creating the dump path and dump
    // id so they are not known to the client.
    success = callback_(dump_path_c_, next_minidump_id_c_, callback_context_,
                        exinfo, assertion, success);
  }

  return success;
}

// static
BOOL CALLBACK ExceptionHandler::MinidumpWriteDumpCallback(
    PVOID context,
    const PMINIDUMP_CALLBACK_INPUT callback_input,
    PMINIDUMP_CALLBACK_OUTPUT callback_output) {
  switch (callback_input->CallbackType) {
  case MemoryCallback: {
    MinidumpCallbackContext* callback_context =
        reinterpret_cast<MinidumpCallbackContext*>(context);
    if (callback_context->iter == callback_context->end)
      return FALSE;

    // Include the specified memory region.
    callback_output->MemoryBase = callback_context->iter->ptr;
    callback_output->MemorySize = callback_context->iter->length;
    callback_context->iter++;
    return TRUE;
  }

    // Include all modules.
  case IncludeModuleCallback:
  case ModuleCallback:
    return TRUE;

    // Include all threads.
  case IncludeThreadCallback:
  case ThreadCallback:
    return TRUE;

    // Stop receiving cancel callbacks.
  case CancelCallback:
    callback_output->CheckCancel = FALSE;
    callback_output->Cancel = FALSE;
    return TRUE;
  }
  // Ignore other callback types.
  return FALSE;
}

bool ExceptionHandler::WriteMinidumpWithExceptionForProcess(
    DWORD requesting_thread_id,
    EXCEPTION_POINTERS* exinfo,
    MDRawAssertionInfo* assertion,
    HANDLE process,
    bool write_requester_stream) {
  bool success = false;
  if (minidump_write_dump_) {
    HANDLE dump_file = CreateFile(next_minidump_path_c_,
                                  GENERIC_WRITE,
                                  0,  // no sharing
                                  NULL,
                                  CREATE_NEW,  // fail if exists
                                  FILE_ATTRIBUTE_NORMAL,
                                  NULL);
    if (dump_file != INVALID_HANDLE_VALUE) {
      MINIDUMP_EXCEPTION_INFORMATION except_info;
      except_info.ThreadId = requesting_thread_id;
      except_info.ExceptionPointers = exinfo;
      except_info.ClientPointers = FALSE;

      // Leave room in user_stream_array for possible breakpad and
      // assertion info streams.
      MINIDUMP_USER_STREAM user_stream_array[2];
      MINIDUMP_USER_STREAM_INFORMATION user_streams;
      user_streams.UserStreamCount = 0;
      user_streams.UserStreamArray = user_stream_array;

      if (write_requester_stream) {
        // Add an MDRawBreakpadInfo stream to the minidump, to provide
        // additional information about the exception handler to the Breakpad
        // processor. The information will help the processor determine which
        // threads are relevant.  The Breakpad processor does not require this
        // information but can function better with Breakpad-generated dumps
        // when it is present. The native debugger is not harmed by the
        // presence of this information.
        MDRawBreakpadInfo breakpad_info;
        breakpad_info.validity = MD_BREAKPAD_INFO_VALID_DUMP_THREAD_ID |
                                 MD_BREAKPAD_INFO_VALID_REQUESTING_THREAD_ID;
        breakpad_info.dump_thread_id = GetCurrentThreadId();
        breakpad_info.requesting_thread_id = requesting_thread_id;

        int index = user_streams.UserStreamCount;
        user_stream_array[index].Type = MD_BREAKPAD_INFO_STREAM;
        user_stream_array[index].BufferSize = sizeof(breakpad_info);
        user_stream_array[index].Buffer = &breakpad_info;
        ++user_streams.UserStreamCount;
      }

      if (assertion) {
        int index = user_streams.UserStreamCount;
        user_stream_array[index].Type = MD_ASSERTION_INFO_STREAM;
        user_stream_array[index].BufferSize = sizeof(MDRawAssertionInfo);
        user_stream_array[index].Buffer = assertion;
        ++user_streams.UserStreamCount;
      }

      // Older versions of DbgHelp.dll don't correctly put the memory around
      // the faulting instruction pointer into the minidump. This
      // callback will ensure that it gets included.
      if (exinfo) {
        // Find a memory region of 256 bytes centered on the
        // faulting instruction pointer.
        const ULONG64 instruction_pointer =
#if defined(_M_IX86)
          exinfo->ContextRecord->Eip;
#elif defined(_M_AMD64)
        exinfo->ContextRecord->Rip;
#else
#error Unsupported platform
#endif

        MEMORY_BASIC_INFORMATION info;
        if (VirtualQueryEx(process,
                           reinterpret_cast<LPCVOID>(instruction_pointer),
                           &info,
                           sizeof(MEMORY_BASIC_INFORMATION)) != 0 &&
            info.State == MEM_COMMIT) {
          // Attempt to get 128 bytes before and after the instruction
          // pointer, but settle for whatever's available up to the
          // boundaries of the memory region.
          const ULONG64 kIPMemorySize = 256;
          ULONG64 base =
            (std::max)(reinterpret_cast<ULONG64>(info.BaseAddress),
                       instruction_pointer - (kIPMemorySize / 2));
          ULONG64 end_of_range =
            (std::min)(instruction_pointer + (kIPMemorySize / 2),
                       reinterpret_cast<ULONG64>(info.BaseAddress)
                       + info.RegionSize);
          ULONG size = static_cast<ULONG>(end_of_range - base);

          AppMemory& elt = app_memory_info_.front();
          elt.ptr = base;
          elt.length = size;
        }
      }

      MinidumpCallbackContext context;
      context.iter = app_memory_info_.begin();
      context.end = app_memory_info_.end();

      // Skip the reserved element if there was no instruction memory
      if (context.iter->ptr == 0) {
        context.iter++;
      }

      MINIDUMP_CALLBACK_INFORMATION callback;
      callback.CallbackRoutine = MinidumpWriteDumpCallback;
      callback.CallbackParam = reinterpret_cast<void*>(&context);

      // The explicit comparison to TRUE avoids a warning (C4800).
      success = (minidump_write_dump_(process,
                                      GetProcessId(process),
                                      dump_file,
                                      dump_type_,
                                      exinfo ? &except_info : NULL,
                                      &user_streams,
                                      &callback) == TRUE);

      CloseHandle(dump_file);
    }
  }

  return success;
}

void ExceptionHandler::UpdateNextID() {
  assert(uuid_create_);
  UUID id = {0};
  if (uuid_create_) {
    uuid_create_(&id);
  }
  next_minidump_id_ = GUIDString::GUIDToWString(&id);
  next_minidump_id_c_ = next_minidump_id_.c_str();

  wchar_t minidump_path[MAX_PATH];
  swprintf(minidump_path, MAX_PATH, L"%s\\%s.dmp",
           dump_path_c_, next_minidump_id_c_);

  // remove when VC++7.1 is no longer supported
  minidump_path[MAX_PATH - 1] = L'\0';

  next_minidump_path_ = minidump_path;
  next_minidump_path_c_ = next_minidump_path_.c_str();
}

void ExceptionHandler::RegisterAppMemory(void* ptr, size_t length) {
  AppMemoryList::iterator iter =
    std::find(app_memory_info_.begin(), app_memory_info_.end(), ptr);
  if (iter != app_memory_info_.end()) {
    // Don't allow registering the same pointer twice.
    return;
  }

  AppMemory app_memory;
  app_memory.ptr = reinterpret_cast<ULONG64>(ptr);
  app_memory.length = static_cast<ULONG>(length);
  app_memory_info_.push_back(app_memory);
}

void ExceptionHandler::UnregisterAppMemory(void* ptr) {
  AppMemoryList::iterator iter =
    std::find(app_memory_info_.begin(), app_memory_info_.end(), ptr);
  if (iter != app_memory_info_.end()) {
    app_memory_info_.erase(iter);
  }
}

}  // namespace google_breakpad