windbg - System.TypeLoadException 예외 분석 사례

이상하군요, 겉으로는 응용 프로그램이 잘 동작하는데 특정 타입의 기능이 먹통입니다. 다행히, JIT 컴파일 내역을 로그로 남기는 기능을 Profiler에 구현해 두었는데, 그것을 통해 System.TypeLoadException 예외가 발생한 것을 알게 되었습니다.

좀 더 구체적인 것은, 해당 예외가 발생한 곳에 예외 처리를 해 상세한 오류 메시지를 남기면 되는데요, 그래도 혹시 현재 상태에서 풀 메모리 덤프를 남겨 원인을 밝힐 수도 있지 않을까요?

운이 좋다면, 결국 특정 스레드에서 예외가 발생한 것이므로 해당 스레드의 스택에 아직 예외가 있는 경우 !threads 명령어로 확인하는 것이 가능합니다.

0:030> !threads
ThreadCount:      11
UnstartedThread:  0
BackgroundThread: 11
PendingThread:    0
DeadThread:       0
Hosted Runtime:   no
                                                                         Lock  
       ID OSID ThreadOBJ    State GC Mode     GC Alloc Context  Domain   Count Apt Exception
   6    1 1730 01cce0f8     28220 Preemptive  00000000:00000000 015d4188 0     Ukn 
  18    2 2cd8 01d3b0e8     2b220 Preemptive  0E007FD4:00000000 015d4188 0     MTA (Finalizer) 
  20    3 29cc 1c386b20   102a220 Preemptive  00000000:00000000 015d4188 0     MTA (Threadpool Worker) 
  21    4 2cb4 1c708ed8     21220 Preemptive  00000000:00000000 015d4188 0     Ukn 
  22    5  888 1da5b758   1020220 Preemptive  00000000:00000000 015d4188 0     Ukn (Threadpool Worker) 
  23    6  bcc 1db17800   1029220 Preemptive  0A2D51CC:00000000 015d4188 0     MTA (Threadpool Worker) 
  24    7  380 1ddb5918   1029220 Preemptive  061B44FC:00000000 015d4188 0     MTA (Threadpool Worker) 
  26    8 1ed0 2109a700   1029220 Preemptive  02063BEC:00000000 015d4188 0     MTA (Threadpool Worker) 
  27    9 175c 1e90e278   1029220 Preemptive  01FDD604:00000000 015d4188 0     MTA (Threadpool Worker) 
   3   10  9d4 213922c0     20220 Preemptive  0E0CA490:00000000 015d4188 0     Ukn 
  29   11 2e5c 21263048   1029220 Preemptive  00000000:00000000 015d4188 0     MTA (Threadpool Worker) 

0:030> !dumpheap -type System.TypeLoadException
 Address       MT     Size
01edd214 1ba07334      100     

Statistics:
      MT    Count    TotalSize Class Name
1ba07334        1          100 System.TypeLoadException
Total 1 objects

0:030> !do 01edd214 
Name:        System.TypeLoadException
MethodTable: 1ba07334
EEClass:     1b9f6850
Size:        100(0x64) bytes
File:        C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll
Fields:
      MT    Field   Offset                 Type VT     Attr    Value Name
1ab1fe08  40002a4        4        System.String  0 instance 00000000 _className
1ba032a4  40002a5        8 ...ection.MethodBase  0 instance 00000000 _exceptionMethod
1ab1fe08  40002a6        c        System.String  0 instance 00000000 _exceptionMethodString
1ab1fe08  40002a7       10        System.String  0 instance 01edd31c _message
1afd6a64  40002a8       14 ...tions.IDictionary  0 instance 00000000 _data
1afd059c  40002a9       18     System.Exception  0 instance 00000000 _innerException
1ab1fe08  40002aa       1c        System.String  0 instance 00000000 _helpURL
1ab167d8  40002ab       20        System.Object  0 instance 01edd4c8 _stackTrace
1ab167d8  40002ac       24        System.Object  0 instance 01edd504 _watsonBuckets
1ab1fe08  40002ad       28        System.String  0 instance 00000000 _stackTraceString
1ab1fe08  40002ae       2c        System.String  0 instance 00000000 _remoteStackTraceString
1ab1ca20  40002af       3c         System.Int32  1 instance        0 _remoteStackIndex
1ab167d8  40002b0       30        System.Object  0 instance 00000000 _dynamicMethods
1ab1ca20  40002b1       40         System.Int32  1 instance -2146233054 _HResult
1ab1fe08  40002b2       34        System.String  0 instance 00000000 _source
1ab1e64c  40002b3       44        System.IntPtr  1 instance        0 _xptrs
1ab1ca20  40002b4       48         System.Int32  1 instance -532462766 _xcode
1ab1e814  40002b5       4c       System.UIntPtr  1 instance        0 _ipForWatsonBuckets
1d35cefc  40002b6       38 ...ializationManager  0 instance 01edd278 _safeSerializationManager
1ab167d8  40002a3       84        System.Object  0   shared   static s_EDILock
    >> Domain:Value  015d4188:NotInit  1c6ff840:NotInit  <<
1ab1fe08  40006ed       50        System.String  0 instance 01edd0fc ClassName
1ab1fe08  40006ee       54        System.String  0 instance 01edd174 AssemblyName
1ab1fe08  40006ef       58        System.String  0 instance 00000000 MessageArg
1ab1ca20  40006f0       5c         System.Int32  1 instance     8344 ResourceId

0:030> !do 01edd31c
Name:        System.String
MethodTable: 1ab1fe08
EEClass:     1ab3e3e4
Size:        414(0x19e) bytes
File:        C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll
String:      Inheritance security rules violated by type: 'MyPackage.MyType'. Derived types must either match the security accessibility of the base type or be less accessible.
Fields:
      MT    Field   Offset                 Type VT     Attr    Value Name
1ab1ca20  4000283        4         System.Int32  1 instance      200 m_stringLength
1ab1b1dc  4000284        8          System.Char  1 instance       49 m_firstChar
1ab1fe08  4000288       70        System.String  0   shared   static Empty
    >> Domain:Value  015d4188:NotInit  1c6ff840:NotInit  <<

.NET CLR4 보안 모델 - 1. "Security Level 2"란?
; https://www.sysnet.pe.kr/2/0/1680

using System;
using System.IO;
using System.Security;

namespace MyPackage
{
    [SecuritySafeCritical]
    public class MyType
    {
        // ... [생략]...
    }
}