summaryrefslogtreecommitdiff
path: root/indra/newview/llwindebug.cpp
blob: 08e30d81df10dd270e183fd783318f1b7f823bd7 (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
/** 
 * @file llwindebug.cpp
 * @brief Windows debugging functions
 *
 * $LicenseInfo:firstyear=2004&license=viewergpl$
 * 
 * Copyright (c) 2004-2007, Linden Research, Inc.
 * 
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlife.com/developers/opensource/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at http://secondlife.com/developers/opensource/flossexception
 * 
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 * 
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include <tchar.h>
#include <tlhelp32.h>
#include "llwindebug.h"
#include "llviewercontrol.h"
#include "lldir.h"
#include "llsd.h"
#include "llsdserialize.h"

#pragma warning(disable: 4200)	//nonstandard extension used : zero-sized array in struct/union
#pragma warning(disable: 4100)	//unreferenced formal parameter


/*
LLSD Block for Windows Dump Information
<llsd>
  <map>
    <key>Platform</key>
    <string></string>
    <key>Process</key>
    <string></string>
    <key>Module</key>
    <string></string>
    <key>DateModified</key>
    <string></string>
    <key>ExceptionCode</key>
    <string></string>
    <key>ExceptionRead/WriteAddress</key>
    <string></string>
    <key>Instruction</key>
    <string></string>
    <key>Registers</key>
    <map>
      <!-- Continued for all registers -->
      <key>EIP</key>
      <string>...</string>
      <!-- ... -->
    </map>
    <key>Call Stack</key>
    <array>
      <!-- One map per stack frame -->
      <map>
	<key>ModuleName</key>
	<string></string>
	<key>ModuleBaseAddress</key>
	<string></string>
	<key>ModuleOffsetAddress</key>
	<string></string>
	<key>Parameters</key>
	<array>
	  <string></string>
	</array>
      </map>
      <!-- ... -->
    </array>
  </map>
</llsd>

*/


extern void (*gCrashCallback)(void);

// based on dbghelp.h
typedef BOOL (WINAPI *MINIDUMPWRITEDUMP)(HANDLE hProcess, DWORD dwPid, HANDLE hFile, MINIDUMP_TYPE DumpType,
									CONST PMINIDUMP_EXCEPTION_INFORMATION ExceptionParam,
									CONST PMINIDUMP_USER_STREAM_INFORMATION UserStreamParam,
									CONST PMINIDUMP_CALLBACK_INFORMATION CallbackParam
									);

MINIDUMPWRITEDUMP f_mdwp = NULL;

#undef UNICODE

static LPTOP_LEVEL_EXCEPTION_FILTER gFilterFunc = NULL;

HMODULE	hDbgHelp;

// Tool Help functions.
typedef	HANDLE (WINAPI * CREATE_TOOL_HELP32_SNAPSHOT)(DWORD dwFlags, DWORD th32ProcessID);
typedef	BOOL (WINAPI * MODULE32_FIRST)(HANDLE hSnapshot, LPMODULEENTRY32 lpme);
typedef	BOOL (WINAPI * MODULE32_NEST)(HANDLE hSnapshot, LPMODULEENTRY32 lpme);

CREATE_TOOL_HELP32_SNAPSHOT	CreateToolhelp32Snapshot_;
MODULE32_FIRST	Module32First_;
MODULE32_NEST	Module32Next_;

#define	DUMP_SIZE_MAX	8000	//max size of our dump
#define	CALL_TRACE_MAX	((DUMP_SIZE_MAX - 2000) / (MAX_PATH + 40))	//max number of traced calls
#define	NL				L"\r\n"	//new line

BOOL WINAPI Get_Module_By_Ret_Addr(PBYTE Ret_Addr, LPWSTR Module_Name, PBYTE & Module_Addr);


void printError( CHAR* msg )
{
  DWORD eNum;
  TCHAR sysMsg[256];
  TCHAR* p;

  eNum = GetLastError( );
  FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
         NULL, eNum,
         MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
         sysMsg, 256, NULL );

  // Trim the end of the line and terminate it with a null
  p = sysMsg;
  while( ( *p > 31 ) || ( *p == 9 ) )
    ++p;
  do { *p-- = 0; } while( ( p >= sysMsg ) &&
                          ( ( *p == '.' ) || ( *p < 33 ) ) );

  // Display the message
  printf( "\n  WARNING: %s failed with error %d (%s)", msg, eNum, sysMsg );
}

BOOL GetProcessThreadIDs(DWORD process_id, std::vector<DWORD>& thread_ids) 
{ 
  HANDLE hThreadSnap = INVALID_HANDLE_VALUE; 
  THREADENTRY32 te32; 
 
  // Take a snapshot of all running threads  
  hThreadSnap = CreateToolhelp32Snapshot( TH32CS_SNAPTHREAD, 0 ); 
  if( hThreadSnap == INVALID_HANDLE_VALUE ) 
    return( FALSE ); 
 
  // Fill in the size of the structure before using it. 
  te32.dwSize = sizeof(THREADENTRY32 ); 
 
  // Retrieve information about the first thread,
  // and exit if unsuccessful
  if( !Thread32First( hThreadSnap, &te32 ) ) 
  {
    printError( "Thread32First" );  // Show cause of failure
    CloseHandle( hThreadSnap );     // Must clean up the snapshot object!
    return( FALSE );
  }

  // Now walk the thread list of the system,
  // and display information about each thread
  // associated with the specified process
  do 
  { 
    if( te32.th32OwnerProcessID == process_id )
    {
      thread_ids.push_back(te32.th32ThreadID); 
    }
  } while( Thread32Next(hThreadSnap, &te32 ) ); 

//  Don't forget to clean up the snapshot object.
  CloseHandle( hThreadSnap );
  return( TRUE );
}

void WINAPI GetCallStackData(const CONTEXT* context_struct, LLSD& info)
{	
    // Fill Str with call stack info.
    // pException can be either GetExceptionInformation() or NULL.
    // If pException = NULL - get current call stack.

    LPWSTR	Module_Name = new WCHAR[MAX_PATH];
	PBYTE	Module_Addr = 0;
	
	typedef struct STACK
	{
		STACK *	Ebp;
		PBYTE	Ret_Addr;
		DWORD	Param[0];
	} STACK, * PSTACK;

	PSTACK	Ebp;

    if(context_struct)
    {
        Ebp = (PSTACK)context_struct->Ebp;
    }
    else
    {
        // The context struct is NULL, 
        // so we will use the current stack.
        Ebp = (PSTACK)&context_struct - 1;

        // Skip frame of GetCallStackData().
		if (!IsBadReadPtr(Ebp, sizeof(PSTACK)))
			Ebp = Ebp->Ebp;		//caller ebp
    }

	// Trace CALL_TRACE_MAX calls maximum - not to exceed DUMP_SIZE_MAX.
	// Break trace on wrong stack frame.
	for (int Ret_Addr_I = 0, i = 0;
		(Ret_Addr_I < CALL_TRACE_MAX) && !IsBadReadPtr(Ebp, sizeof(PSTACK)) && !IsBadCodePtr(FARPROC(Ebp->Ret_Addr));
		Ret_Addr_I++, Ebp = Ebp->Ebp, ++i)
	{
		// If module with Ebp->Ret_Addr found.

		if (Get_Module_By_Ret_Addr(Ebp->Ret_Addr, Module_Name, Module_Addr))
		{
			// Save module's address and full path.
			info["CallStack"][i]["ModuleName"] = ll_convert_wide_to_string(Module_Name);
			info["CallStack"][i]["ModuleAddress"] = (int)Module_Addr;
			info["CallStack"][i]["CallOffset"] = (int)(Ebp->Ret_Addr - Module_Addr);

			LLSD params;
			// Save 5 params of the call. We don't know the real number of params.
			if (!IsBadReadPtr(Ebp, sizeof(PSTACK) + 5 * sizeof(DWORD)))
			{
				for(int j = 0; j < 5; ++j)
				{
					params[j] = (int)Ebp->Param[j];
				}
			}
			info["CallStack"][i]["Parameters"] = params;
		}
		info["CallStack"][i]["ReturnAddress"] = (int)Ebp->Ret_Addr;			
	}
}

BOOL GetThreadCallStack(DWORD thread_id, LLSD& info)
{
    if(GetCurrentThreadId() == thread_id)
    {
        // Early exit for the current thread.
        // Suspending the current thread would be a bad idea.
        // Plus you can't retrieve a valid current thread context.
        return false;
    }

    HANDLE thread_handle = INVALID_HANDLE_VALUE; 
    thread_handle = OpenThread(THREAD_ALL_ACCESS, FALSE, thread_id);
    if(INVALID_HANDLE_VALUE == thread_handle)
    {
        return FALSE;
    }

    BOOL result = false;
    if(-1 != SuspendThread(thread_handle))
    {
        CONTEXT context_struct;
        context_struct.ContextFlags = CONTEXT_FULL;
        if(GetThreadContext(thread_handle, &context_struct))
        {
            GetCallStackData(&context_struct, info);
            result = true;
        }
        ResumeThread(thread_handle);
    }
    else
    {
        // Couldn't suspend thread.
    }

    CloseHandle(thread_handle);
    return result;
}


//Windows Call Stack Construction idea from 
//http://www.codeproject.com/tools/minidump.asp

//****************************************************************************************
BOOL WINAPI Get_Module_By_Ret_Addr(PBYTE Ret_Addr, LPWSTR Module_Name, PBYTE & Module_Addr)
//****************************************************************************************
// Find module by Ret_Addr (address in the module).
// Return Module_Name (full path) and Module_Addr (start address).
// Return TRUE if found.
{
	MODULEENTRY32	M = {sizeof(M)};
	HANDLE	hSnapshot;

	bool found = false;
	
	if (CreateToolhelp32Snapshot_)
	{
		hSnapshot = CreateToolhelp32Snapshot_(TH32CS_SNAPMODULE, 0);
		
		if ((hSnapshot != INVALID_HANDLE_VALUE) &&
			Module32First_(hSnapshot, &M))
		{
			do
			{
				if (DWORD(Ret_Addr - M.modBaseAddr) < M.modBaseSize)
				{
					lstrcpyn(Module_Name, M.szExePath, MAX_PATH);
					Module_Addr = M.modBaseAddr;
					found = true;
					break;
				}
			} while (Module32Next_(hSnapshot, &M));
		}

		CloseHandle(hSnapshot);
	}

	return found;
} //Get_Module_By_Ret_Addr

//******************************************************************
void WINAPI Get_Call_Stack(PEXCEPTION_POINTERS pException, LLSD& info)
//******************************************************************
// Fill Str with call stack info.
// pException can be either GetExceptionInformation() or NULL.
// If pException = NULL - get current call stack.
{	
	LPWSTR	Module_Name = new WCHAR[MAX_PATH];
	PBYTE	Module_Addr = 0;
	
	typedef struct STACK
	{
		STACK *	Ebp;
		PBYTE	Ret_Addr;
		DWORD	Param[0];
	} STACK, * PSTACK;

	STACK	Stack = {0, 0};
	PSTACK	Ebp;

	if (pException)		//fake frame for exception address
	{
		Stack.Ebp = (PSTACK)pException->ContextRecord->Ebp;
		Stack.Ret_Addr = (PBYTE)pException->ExceptionRecord->ExceptionAddress;
		Ebp = &Stack;
	}
	else
	{
		Ebp = (PSTACK)&pException - 1;	//frame addr of Get_Call_Stack()

		// Skip frame of Get_Call_Stack().
		if (!IsBadReadPtr(Ebp, sizeof(PSTACK)))
			Ebp = Ebp->Ebp;		//caller ebp
	}

	// Trace CALL_TRACE_MAX calls maximum - not to exceed DUMP_SIZE_MAX.
	// Break trace on wrong stack frame.
	for (int Ret_Addr_I = 0, i = 0;
		(Ret_Addr_I < CALL_TRACE_MAX) && !IsBadReadPtr(Ebp, sizeof(PSTACK)) && !IsBadCodePtr(FARPROC(Ebp->Ret_Addr));
		Ret_Addr_I++, Ebp = Ebp->Ebp, ++i)
	{
		// If module with Ebp->Ret_Addr found.

		if (Get_Module_By_Ret_Addr(Ebp->Ret_Addr, Module_Name, Module_Addr))
		{
			// Save module's address and full path.
			info["CallStack"][i]["ModuleName"] = ll_convert_wide_to_string(Module_Name);
			info["CallStack"][i]["ModuleAddress"] = (int)Module_Addr;
			info["CallStack"][i]["CallOffset"] = (int)(Ebp->Ret_Addr - Module_Addr);

			LLSD params;
			// Save 5 params of the call. We don't know the real number of params.
			if (pException && !Ret_Addr_I)	//fake frame for exception address
				params[0] = "Exception Offset";
			else if (!IsBadReadPtr(Ebp, sizeof(PSTACK) + 5 * sizeof(DWORD)))
			{
				for(int j = 0; j < 5; ++j)
				{
					params[j] = (int)Ebp->Param[j];
				}
			}
			info["CallStack"][i]["Parameters"] = params;
		}
		info["CallStack"][i]["ReturnAddress"] = (int)Ebp->Ret_Addr;			
	}
} //Get_Call_Stack

//***********************************
void WINAPI Get_Version_Str(LLSD& info)
//***********************************
// Fill Str with Windows version.
{
	OSVERSIONINFOEX	V = {sizeof(OSVERSIONINFOEX)};	//EX for NT 5.0 and later

	if (!GetVersionEx((POSVERSIONINFO)&V))
	{
		ZeroMemory(&V, sizeof(V));
		V.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
		GetVersionEx((POSVERSIONINFO)&V);
	}

	if (V.dwPlatformId != VER_PLATFORM_WIN32_NT)
		V.dwBuildNumber = LOWORD(V.dwBuildNumber);	//for 9x HIWORD(dwBuildNumber) = 0x04xx

	info["Platform"] = llformat("Windows:  %d.%d.%d, SP %d.%d, Product Type %d",	//SP - service pack, Product Type - VER_NT_WORKSTATION,...
		V.dwMajorVersion, V.dwMinorVersion, V.dwBuildNumber, V.wServicePackMajor, V.wServicePackMinor, V.wProductType);
} //Get_Version_Str

//*************************************************************
LLSD WINAPI Get_Exception_Info(PEXCEPTION_POINTERS pException)
//*************************************************************
// Allocate Str[DUMP_SIZE_MAX] and return Str with dump, if !pException - just return call stack in Str.
{
	LLSD info;
	LPWSTR		Str;
	int			Str_Len;
//	int			i;
	LPWSTR		Module_Name = new WCHAR[MAX_PATH];
	PBYTE		Module_Addr;
	HANDLE		hFile;
	FILETIME	Last_Write_Time;
	FILETIME	Local_File_Time;
	SYSTEMTIME	T;

	Str = new WCHAR[DUMP_SIZE_MAX];
	Str_Len = 0;
	if (!Str)
		return NULL;
	
	Get_Version_Str(info);
	
	GetModuleFileName(NULL, Str, MAX_PATH);
	info["Process"] = ll_convert_wide_to_string(Str);
	info["ThreadID"] = (S32)GetCurrentThreadId();

	// If exception occurred.
	if (pException)
	{
		EXCEPTION_RECORD &	E = *pException->ExceptionRecord;
		CONTEXT &			C = *pException->ContextRecord;

		// If module with E.ExceptionAddress found - save its path and date.
		if (Get_Module_By_Ret_Addr((PBYTE)E.ExceptionAddress, Module_Name, Module_Addr))
		{
			info["Module"] = ll_convert_wide_to_string(Module_Name);

			if ((hFile = CreateFile(Module_Name, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING,
				FILE_ATTRIBUTE_NORMAL, NULL)) != INVALID_HANDLE_VALUE)
			{
				if (GetFileTime(hFile, NULL, NULL, &Last_Write_Time))
				{
					FileTimeToLocalFileTime(&Last_Write_Time, &Local_File_Time);
					FileTimeToSystemTime(&Local_File_Time, &T);

					info["DateModified"] = llformat("%02d/%02d/%d", T.wMonth, T.wDay, T.wYear);
				}
				CloseHandle(hFile);
			}
		}
		else
		{
			info["ExceptionAddr"] = (int)E.ExceptionAddress;
		}
		
		info["ExceptionCode"] = (int)E.ExceptionCode;
		
		/*
		//TODO: Fix this
		if (E.ExceptionCode == EXCEPTION_ACCESS_VIOLATION)
		{
			// Access violation type - Write/Read.
			LLSD exception_info;
			exception_info["Type"] = E.ExceptionInformation[0] ? "Write" : "Read";
			exception_info["Address"] = llformat("%08x", E.ExceptionInformation[1]);
			info["Exception Information"] = exception_info;
		}
		*/

		
		// Save instruction that caused exception.
		/*
		std::string str;
		for (i = 0; i < 16; i++)
			str += llformat(" %02X", PBYTE(E.ExceptionAddress)[i]);
		info["Instruction"] = str;
		*/
		LLSD registers;
		registers["EAX"] = (int)C.Eax;
		registers["EBX"] = (int)C.Ebx;
		registers["ECX"] = (int)C.Ecx;
		registers["EDX"] = (int)C.Edx;
		registers["ESI"] = (int)C.Esi;
		registers["EDI"] = (int)C.Edi;
		registers["ESP"] = (int)C.Esp;
		registers["EBP"] = (int)C.Ebp;
		registers["EIP"] = (int)C.Eip;
		registers["EFlags"] = (int)C.EFlags;
		info["Registers"] = registers;
	} //if (pException)
	
	// Save call stack info.
	Get_Call_Stack(pException, info);

	return info;
} //Get_Exception_Info

#define UNICODE


class LLMemoryReserve {
public:
	LLMemoryReserve();
	~LLMemoryReserve();
	void reserve();
	void release();
protected:
	unsigned char *mReserve;
	static const size_t MEMORY_RESERVATION_SIZE;
};

LLMemoryReserve::LLMemoryReserve() :
	mReserve(NULL)
{
};

LLMemoryReserve::~LLMemoryReserve()
{
	release();
}

// I dunno - this just seemed like a pretty good value.
const size_t LLMemoryReserve::MEMORY_RESERVATION_SIZE = 5 * 1024 * 1024;

void LLMemoryReserve::reserve()
{
	if(NULL == mReserve)
		mReserve = new unsigned char[MEMORY_RESERVATION_SIZE];
};

void LLMemoryReserve::release()
{
	delete [] mReserve;
	mReserve = NULL;
};

static LLMemoryReserve gEmergencyMemoryReserve;

#ifndef _M_IX86
	#error "The following code only works for x86!"
#endif
LPTOP_LEVEL_EXCEPTION_FILTER WINAPI MyDummySetUnhandledExceptionFilter(
	LPTOP_LEVEL_EXCEPTION_FILTER lpTopLevelExceptionFilter)
{
	if(lpTopLevelExceptionFilter ==  gFilterFunc)
		return gFilterFunc;

	llinfos << "Someone tried to set the exception filter. Listing call stack modules" << llendl;
	LLSD cs_info;
	GetCallStackData(NULL, cs_info);
	
	if(cs_info.has("CallStack") && cs_info["CallStack"].isArray())
	{
		LLSD cs = cs_info["CallStack"];
		for(LLSD::array_iterator i = cs.beginArray(); 
			i != cs.endArray(); 
			++i)
		{
			llinfos << "Module: " << (*i)["ModuleName"] << llendl;
		}
	}
	
	return gFilterFunc;
}

BOOL PreventSetUnhandledExceptionFilter()
{
	HMODULE hKernel32 = LoadLibrary(_T("kernel32.dll"));
	if (hKernel32 == NULL) 
		return FALSE;

	void *pOrgEntry = GetProcAddress(hKernel32, "SetUnhandledExceptionFilter");
	if(pOrgEntry == NULL) 
		return FALSE;
	
	unsigned char newJump[ 100 ];
	DWORD dwOrgEntryAddr = (DWORD)pOrgEntry;
	dwOrgEntryAddr += 5; // add 5 for 5 op-codes for jmp far
	void *pNewFunc = &MyDummySetUnhandledExceptionFilter;
	DWORD dwNewEntryAddr = (DWORD) pNewFunc;
	DWORD dwRelativeAddr = dwNewEntryAddr - dwOrgEntryAddr;

	newJump[ 0 ] = 0xE9;  // JMP absolute
	memcpy(&newJump[ 1 ], &dwRelativeAddr, sizeof(pNewFunc));
	SIZE_T bytesWritten;
	BOOL bRet = WriteProcessMemory(GetCurrentProcess(),
	pOrgEntry, newJump, sizeof(pNewFunc) + 1, &bytesWritten);
	return bRet;
}

// static
void  LLWinDebug::initExceptionHandler(LPTOP_LEVEL_EXCEPTION_FILTER filter_func)
{

	static bool s_first_run = true;
	// Load the dbghelp dll now, instead of waiting for the crash.
	// Less potential for stack mangling

	if (s_first_run)
	{
		// First, try loading from the directory that the app resides in.
		std::string local_dll_name = gDirUtilp->findFile("dbghelp.dll", gDirUtilp->getWorkingDir(), gDirUtilp->getExecutableDir());

		HMODULE hDll = NULL;
		hDll = LoadLibraryA(local_dll_name.c_str());
		if (!hDll)
		{
			hDll = LoadLibrary(L"dbghelp.dll");
		}

		if (!hDll)
		{
			LL_WARNS("AppInit") << "Couldn't find dbghelp.dll!" << LL_ENDL;
		}
		else
		{
			f_mdwp = (MINIDUMPWRITEDUMP) GetProcAddress(hDll, "MiniDumpWriteDump");

			if (!f_mdwp)
			{
				FreeLibrary(hDll);
				hDll = NULL;
			}
		}

		gEmergencyMemoryReserve.reserve();

		s_first_run = false;
	}

	// Try to get Tool Help library functions.
	HMODULE hKernel32;
	hKernel32 = GetModuleHandle(_T("KERNEL32"));
	CreateToolhelp32Snapshot_ = (CREATE_TOOL_HELP32_SNAPSHOT)GetProcAddress(hKernel32, "CreateToolhelp32Snapshot");
	Module32First_ = (MODULE32_FIRST)GetProcAddress(hKernel32, "Module32FirstW");
	Module32Next_ = (MODULE32_NEST)GetProcAddress(hKernel32, "Module32NextW");

    LPTOP_LEVEL_EXCEPTION_FILTER prev_filter;
	prev_filter = SetUnhandledExceptionFilter(filter_func);

	// *REMOVE:Mani
	//PreventSetUnhandledExceptionFilter();

	if(prev_filter != gFilterFunc)
	{
		LL_WARNS("AppInit") 
			<< "Replacing unknown exception (" << (void *)prev_filter << ") with (" << (void *)filter_func << ") !" << LL_ENDL;
	}
	
	gFilterFunc = filter_func;
}

bool LLWinDebug::checkExceptionHandler()
{
	bool ok = true;
	LPTOP_LEVEL_EXCEPTION_FILTER prev_filter;
	prev_filter = SetUnhandledExceptionFilter(gFilterFunc);

	if (prev_filter != gFilterFunc)
	{
		LL_WARNS("AppInit") << "Our exception handler (" << (void *)gFilterFunc << ") replaced with " << prev_filter << "!" << LL_ENDL;
		ok = false;
	}

	if (prev_filter == NULL)
	{
		ok = FALSE;
		if (gFilterFunc == NULL)
		{
			LL_WARNS("AppInit") << "Exception handler uninitialized." << LL_ENDL;
		}
		else
		{
			LL_WARNS("AppInit") << "Our exception handler (" << (void *)gFilterFunc << ") replaced with NULL!" << LL_ENDL;
		}
	}

	return ok;
}

void LLWinDebug::writeDumpToFile(MINIDUMP_TYPE type, MINIDUMP_EXCEPTION_INFORMATION *ExInfop, const std::string& filename)
{
	if(f_mdwp == NULL || gDirUtilp == NULL) 
	{
		return;
		//write_debug("No way to generate a minidump, no MiniDumpWriteDump function!\n");
	}
	else
	{
		std::string dump_path = gDirUtilp->getExpandedFilename(LL_PATH_LOGS, filename);

		HANDLE hFile = CreateFileA(dump_path.c_str(),
									GENERIC_WRITE,
									FILE_SHARE_WRITE,
									NULL,
									CREATE_ALWAYS,
									FILE_ATTRIBUTE_NORMAL,
									NULL);

		if (hFile != INVALID_HANDLE_VALUE)
		{
			// Write the dump, ignoring the return value
			f_mdwp(GetCurrentProcess(),
					GetCurrentProcessId(),
					hFile,
					type,
					ExInfop,
					NULL,
					NULL);

			CloseHandle(hFile);
		}

	}
}

// static
void LLWinDebug::generateCrashStacks(struct _EXCEPTION_POINTERS *exception_infop)
{
	// *NOTE:Mani - This method is no longer the exception handler.
	// Its called from viewer_windows_exception_handler() and other places.

	// 
	// Let go of a bunch of reserved memory to give library calls etc
	// a chance to execute normally in the case that we ran out of
	// memory.
	//
	LLSD info;
	std::string dump_path = gDirUtilp->getExpandedFilename(LL_PATH_LOGS,
												"SecondLifeException");
	std::string log_path = dump_path + ".log";

	if (exception_infop)
	{
		// Since there is exception info... Release the hounds.
		gEmergencyMemoryReserve.release();

		if(gSavedSettings.getControl("SaveMinidump").notNull() && gSavedSettings.getBOOL("SaveMinidump"))
		{
			_MINIDUMP_EXCEPTION_INFORMATION ExInfo;

			ExInfo.ThreadId = ::GetCurrentThreadId();
			ExInfo.ExceptionPointers = exception_infop;
			ExInfo.ClientPointers = NULL;

			writeDumpToFile(MiniDumpNormal, &ExInfo, "SecondLife.dmp");
			writeDumpToFile((MINIDUMP_TYPE)(MiniDumpWithDataSegs | MiniDumpWithIndirectlyReferencedMemory), &ExInfo, "SecondLifePlus.dmp");
		}

		info = Get_Exception_Info(exception_infop);
	}

	LLSD threads;
    std::vector<DWORD> thread_ids;
    GetProcessThreadIDs(GetCurrentProcessId(), thread_ids);

    for(std::vector<DWORD>::iterator th_itr = thread_ids.begin(); 
                th_itr != thread_ids.end();
                ++th_itr)
    {
        LLSD thread_info;
        if(*th_itr != GetCurrentThreadId())
        {
            GetThreadCallStack(*th_itr, thread_info);
        }

        if(thread_info)
        {
            threads[llformat("ID %d", *th_itr)] = thread_info;
        }
    }

    info["Threads"] = threads;

	llofstream out_file(log_path);
	LLSDSerialize::toPrettyXML(info, out_file);
	out_file.close();
}

void LLWinDebug::clearCrashStacks()
{
	LLSD info;
	std::string dump_path = gDirUtilp->getExpandedFilename(LL_PATH_LOGS, "SecondLifeException.log");
	LLFile::remove(dump_path);
}