Software Diagnostics Library

A page to reference all different kinds of process related patterns is necessary, so I created this post:

• Virtualized Process (WOW64)
• Coupled Processes (strong)
• Coupled Processes (weak)
• Coupled Processes (semantics)
• Manual Dump (process)
• Wait Chain (process objects)
• No Process Dumps
• Special Process
• Zombie Processes
• Process Factory
• Missing Process
• Fat Process Dump
• Value Adding Process
• Frozen Process
• Hidden Process
• One-Thread Process
• Crashed Process
• Past Process

I’ll update it as soon as I add more similar patterns.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

A page to reference all different kinds of thread related patterns is necessary, so I created this post:

• Spiking Thread
• Waiting Thread Time (kernel dumps)
• Waiting Thread Time (user dumps)
• Missing Thread (user space)
• Missing Thread (kernel space)
• Passive Thread (user space)
• Passive System Thread (kernel space)
• Main Thread
• Wait Chain (thread objects)
• Suspended Thread
• Blocked Thread (software)
• Blocked Thread (hardware)
• Blocked Thread (timeout)
• Thread Starvation (realtime priority)
• Thread Starvation (normal priority)
• Affine Thread
• CLR Thread
• Thread Age
• Special Thread (.NET CLR)
• No Current Thread
• Active Thread (Mac OS X)
• One-Thread Process
• Thread Cluster
• Ghost Thread
• Thread Poset
• Active Thread (Windows)
• Not My Thread
• Data Correlation (CPU times)
• Shared Thread

I’ll update it as soon as I add more similar patterns.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Before deciding on whether to retrospect on 2012 we found that since March 14, 2008 this site has had more than 1 million visitors with more than 33% returning. So instead of just 2012 we decided to retrospect on that interval up to December 31, 2012. Google Analytics has improved since last January, 2012 and now made our task easier. So we start with the first one hundred sites referring to us:

Next table is distribution of visits among countries:

Then the first 100 network locations:

Then the first 100 search keywords and phrases that led to us:

Then browser stats (we have never thought that there are so many of them):

Browser	Visits
Internet Explorer	446051
Firefox	356686
Chrome	184535
Opera	45787
Safari	24123
Mozilla	3780
Mozilla Compatible Agent	2401
Android Browser	1337
Konqueror	1057
IE with Chrome Frame	982
Opera Mini	705
SeaMonkey	503
Safari (in-app)	197
Lunascape	144
BlackBerry8900	128
Camino	126
RockMelt	124
(not set)	96
Netscape	72
Playstation 3	36
IUC	34
Googlebot	29
Lynx	24
Unsupported Browser Version	22
BlackBerry9630	21
NetFront	17
BlackBerry9700	15
Microsoft-Symbol-Server	14
BlackBerry9000	12
Galeon	11
Midori	9
NokiaE63	9
Yahoo! Slurp	9
BlackBerry8530	8
BlackBerry8520	7
PagePeeker.com	7
SAMSUNG-SGH-I617	7
BlackBerry9530	6
JUC	6
MSR-ISRCCrawler	6
OpenWave	6
anonimo	5
BlackBerry9300	5
HTC_HD2_T8585 Opera	5
Nokia5233	5
Space Bison	5
-Vasya	4
Blazer	4
Uzbl	4
-^_^- Hello	3
<?echo ‘<pre>’; system	3
12345	3
BlackBerry9330	3
BlackBerry9650	3
HTC_P3700 Opera	3
HTC_TyTN_II Mozilla	3
NOKIAN78	3
Playstation Portable	3
PPC; 240×320; HTC_P3450	3
undefined GoogleToolbarBB	3
anonymous	2
Empty	2
GreatBrowse	2
Helyi user agent	2
HTC_Touch_Pro2_T7373 Opera	2
HTC_Touch2_T3333 Opera	2
J2ME	2
Mozilla 5.0	2
NokiaC1-01	2
NokiaC3-00	2
NokiaC7-00	2
NokiaX2-01	2
nwzfq	2
test	2
—	1
?M5	1
“PagePeeker.com”	1
<?include	1
<script>alert	1
<SCRIPT>window.location=’http:	1
2.0.0.11	1
31337′	1
8900b	1
AltaVista Intranet V2.0 evreka.com crawler@evreka.com	1
annoying	1
AppEngine-Google;	1
BlackBerry9500	1
BlackBerry9550	1
bwh3_user_agent	1
Citrix	1
EBABrowser	1
EY	1
fake_user_agent Mozilla	1
FAST Enterprise Crawler 6 used by Reed Exhibitions	1
foo	1
General Browser	1
GOOGLEBOT	1
HD_mini_T5555 Opera	1
Hellbrowser 6.66	1
holy_teacher FirePHP	1
HTC_P3490 Opera	1
HTC_P4550 Mozilla	1
HTC_Polaris Mozilla	1
HTC_Touch_3G_T3232 Opera	1
HTC_Touch_HD_T8282 Opera	1
HTC_Touch_Pro_T7272 Opera	1
HTC_Touch2_T3320 Opera	1
HTC-8900	1
IE 8	1
IE6	1
iTunes	1
Keep Out	1
KraftwayBrowser2	1
Links	1
Maemo Browser	1
Medusa	1
MERONG	1
Motorola_ES405B	1
mozilla	1
Mozilla Firefox	1
MS-OC 4.0	1
msie	1
NCSA Mosaic	1
NightDynamo AdminPanel v0.2.1	1
Nokia2700c-2	1
Nokia2730c-1	1
Nokia305	1
Nokia5230	1
Nokia5310XpressMusic	1
Nokia5800 XpressMusic	1
Nokia6300	1
Nokia6700c-1	1
NokiaC2-01	1
NokiaC2-02	1
NokiaC2-03	1
NokiaC5-03	1
nokiac6-00	1
NokiaC6-00	1
NOKIAE65	1
NokiaE66	1
NokiaE71	1
NokiaE71-2;Mozilla	1
NokiaE72-1	1
NokiaN-GageQD	1
NokiaN70-1	1
NokiaNokia 6210s	1
NoneOfYourBusiness	1
nothisname_wangxiaoyang3	1
OmniWeb	1
Palm750	1
Peeplo Screenshot Bot	1
PerTrUsTsQuiD	1
pippos.7	1
PPC; 480×800; HTC_Touch_HD_T8282; OpVer 34.159.1.612	1
PriceGoblin User Agent	1
Private	1
Privoxy	1
Read Later	1
SAMSUNG-GT-E2222	1
samsung-gt-s3653	1
samsung-gt-s3653 UNTRUSTED	1
SAMSUNG-S8000	1
SAMSUNG-SGH-I637	1
Samsung-SPHM540 Polaris	1
SmallProxy 3.5.4	1
SonyEricssonK750	1
Surf	1
tdhbrowser	1
TiFiC Client Z	1
union update table sd_users set userid=9 where username=’coco	1
unknown	1
Unknown	1
UNTRUSTED	1
Updownerbot	1
WIN	1
WinXP SP2	1
Wlwap	1
WM5 PIE	1
Xda_orbit_2; 240×320	1
Xyi znat kakoi browser MRA 5.7	1
ZooShot 0.1a	1
ZooShot 0.42	1

and finally mobile devices stats (you may find your own device there):

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

This pattern is called Opposition Messages (borrowed from binary opposition originated in Saussure’s structuralism). It covers the following pairs of messages usually found in software traces and logs such as:

• open / close
• create / destroy
• allocate / free (deallocate)
• call / return
• enter / exit (leave)
• load / unload
• save / load
• lock / unlock
• map / unmap

The absence of an opposite may point to some problems such as synchronization and leaks or Incomplete History (wait chains). There can always be a possibility that a second term is missing due to Sparse Trace but this is a poor implementation choice that leads to confusion during troubleshooting and debugging.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Some tracing tools such as Citrix CDFControl have an option to split software traces and logs into several files during long recording. Although this should be done judiciously it is really necessary sometimes. We call this pattern Split Trace. What to do if we get several trace files and we want to use some other analysis tool such as Citrix CDFAnalyzer? If we know that the problem happened just before the tracing was stopped we can look at the last few such files from the file sequence (although we recommend a circular trace here). Otherwise we can convert them into CVS files and import into Excel which also supports adjoint threading.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

We have decided to factor out Anchor Messages example of message interleave into another pattern called Message Interleave. It covers superposition of different anchor messages, for example, process launch and exit, or DLL load and unload:

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Sometimes we don’t see anything in the trace or see very little because particular source code fragment was not covered by trace statements (see also PLOTs):

We call this pattern Sparse Trace and this is different from Missing Component pattern where some modules were not included for tracing explicitly although there is tracing code there or Visibility Limit pattern where tracing is intrinsically impossible. Often technical support and escalation engineers request to add more trace statements and software engineers extend tracing coverage iteratively as needed.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

I get many questions on whether software log analysis patterns from Software Diagnostics Institute are OS or platform or product specific. My answer is that they are independent from all of them because they are based on viewing software logs as stories of computation and were discovered by application of narratological analysis (software narratology). In addition to these patterns there exist domain specific problem patterns such as wrong hotfix level or specific product error code during software installation or execution. Typical examples of support for such platform and product specific type of patterns include Microsoft Windows Problem Reporting and Citrix Auto Support.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

A page to reference all different kinds of optimization patterns is necessary, so I created this post:

• Optimized Code (function parameter reuse)
• OMAP Code Optimization
• Optimized VM Layout
• Inline Function Optimization (unmanaged code)
• Inline Function Optimization (managed code)
• False Function Parameters
• Hidden Parameter

I’ll update it as soon as I add more similar patterns.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Finally, the new version of WinDbg: A Reference Poster and Learning Cards is under development. This time every page is published online for comments, suggestions and corrections which are very welcome. The format of every page follows colored memory space diagram where red cards are for native kernel space commands, blue cards are for unmanaged user space, and green cards are for managed .NET space (click on a picture to open a PDF file):

Download page 1 PDF file

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Pattern-driven software post-construction problem solving involves using preexisting pattern languages and pattern catalogs for software diagnostics, troubleshooting and debugging. Pattern-based software post-construction problem solving addresses PLS (Pattern Life Cycle) - from the discovery of a new pattern through its integration into an existing catalog and language, testing, packaging and delivering to pattern consumers with subsequent usage, refactoring and writing case studies:

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

While working on Accelerated Windows Software Trace Analysis training I discovered some missing patterns needed for completeness despite their triviality. One of them is called Error Message. Here an error is reported either explicitly (”operation failed”) or implicitly as an operation status result such as 0xC00000XX. Sometimes, a trace message designer specifies that the number value was supplied for information only and should be ignored. Some error messages may contain information that is not relevant for the current software incident, the so called false positive errors. Some tracing architectures and tools include message information category for errors, such as Citrix CDF (ETW-based) where you filter by error category to get an adjoint thread. Note, that the association of a trace statement with an error category is left at the discretion of an engineer writing code and information category messages may contain implicit errors such as last error and return status reports.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

The case of an error reporting fault chain led me to First Fault Stack Trace memory dump analysis pattern that corresponds to First Fault software diagnostics pattern proper. Here the term first fault is used for an exception that was either ignored by surrounding code or led to other exceptions or error message boxes with stack traces that masked the first one. Typical examples where it is sometimes possible to get a first exception stack trace include but not limited to:

• Fault in error reporting started as a fault in in some other process
• Hidden exception in user or kernel space
• Double fault
• Nested exception in unmanaged and managed code
• Nested offender

It is also sometimes possible unless a stack region was paged out to get partial stack traces from execution residue when the sequence of return addresses was partially overwritten by subsequently executed code.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Periodic Message Block is similar to Periodic Error but not limited to errors or failure reports. One such example we recently encountered is when some adjoint activity (such as messages from specific PID) stop to appear after the middle of the trace and after that there are repeated blocks of similar messages from different PIDs with their threads checking for some condition (waiting for event and reporting timeouts):

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Forthcoming Accelerated Windows Software Trace Analysis Training.

These are important meta-patterns of monitoring and software problem analysis reports. It is often the case that we have software artifacts and some problem description and we need to provide recommendations on further troubleshooting. Most of the time such an analysis and associated response fit into abstract schemes where we can just substitute variables for concrete states, actions, artifacts and behavioral descriptions. Sometimes we also have difficulty to write such analysis reports so we hope report schemes is of help here to provide organizing templates for thought process. The first such scheme we call Missing Cause Trace:

1. If Action then Behavior
2. We have a trace of Behavior
3. We need a trace of Action and Behavior

The difference with Truncated Trace pattern here is that in a truncated trace it was intended to trace certain behaviour but the tracing session was stopped prematurely or started too late. In a missing cause trace only a part of necessary activity was traced and the missing part wasn’t thought of or considered for tracing.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

The modern software trace recording, visualization and analysis tools such as Process Monitor, Xperf, WPR and WPA provide stack traces associated with trace messages. Consider stack traces as software traces we have, in a more general case, traces (fibers) bundled together on (attached to) a base software trace. For example, a trace message, that mentions an IRP can have its I/O stack attached together with thread stack trace with function calls leading to a function that emitted the trace message. Another example is association of different types of traces with trace messages such as managed and unmanaged ones. This general trace analysis pattern needs a name so we opted for Fiber Bundle as analogy with a fiber bundle from mathematics. Here’s a graphical representation of stack traces recorded for each trace message where one message also has an associated I/O stack trace:

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

This is a high contention pattern variant where the contention is around a monitor object. For example, we have a distributed CPU spike for some threads:

0:000> !runaway
 User Mode Time
  Thread       Time
   9:6ff4      0 days 0:07:39.019
  12:6b88      0 days 0:06:19.786
  11:6bf0      0 days 0:06:13.889
  10:6930      0 days 0:06:09.240
  16:3964      0 days 0:05:44.483
  17:6854      0 days 0:05:35.326
  13:668c      0 days 0:05:35.123
  14:5594      0 days 0:05:34.858
  15:7248      0 days 0:05:23.111
   2:c54       0 days 0:00:41.215
   4:1080      0 days 0:00:00.349
   7:10f0      0 days 0:00:00.302
   0:c3c       0 days 0:00:00.271
[...]

If we look at their stack traces we find them all blocked trying to enter a monitor, for example:

0:000> ~*k

[...]

  12  Id: d50.6b88 Suspend: 0 Teb: 000007ff`fffd8000 Unfrozen
Child-SP          RetAddr           Call Site
00000000`1a98e798 000007fe`fd0c1420 ntdll!ZwWaitForMultipleObjects+0xa
00000000`1a98e7a0 00000000`76e82cf3 KERNELBASE!WaitForMultipleObjectsEx+0xe8
00000000`1a98e8a0 000007fe`f82e0669 kernel32!WaitForMultipleObjectsExImplementation+0xb3
00000000`1a98e930 000007fe`f82dbec9 mscorwks!WaitForMultipleObjectsEx_SO_TOLERANT+0xc1
00000000`1a98e9d0 000007fe`f82a0569 mscorwks!Thread::DoAppropriateAptStateWait+0x41
00000000`1a98ea30 000007fe`f82beaec mscorwks!Thread::DoAppropriateWaitWorker+0x191
00000000`1a98eb30 000007fe`f81f1b9a mscorwks!Thread::DoAppropriateWait+0x5c
00000000`1a98eba0 000007fe`f82fd3c9 mscorwks!CLREvent::WaitEx+0xbe
00000000`1a98ec50 000007fe`f81ac6be mscorwks!AwareLock::EnterEpilog+0xc9
00000000`1a98ed20 000007fe`f81c7b2b mscorwks!AwareLock::Enter+0x72
00000000`1a98ed50 000007fe`f87946af mscorwks!AwareLock::Contention+0x1fb
00000000`1a98ee20 000007ff`00161528 mscorwks!JITutil_MonContention+0xdf
00000000`1a98efd0 000007ff`0016140e 0×7ff`00161528
00000000`1a98f040 000007ff`00167271 0×7ff`0016140e
00000000`1a98f0a0 000007fe`f74e2bbb 0×7ff`00167271
00000000`1a98f130 000007fe`f753ed76 mscorlib_ni+0×2f2bbb
00000000`1a98f180 000007fe`f8390282 mscorlib_ni+0×34ed76
00000000`1a98f1d0 000007fe`f8274363 mscorwks!CallDescrWorker+0×82
00000000`1a98f220 000007fe`f8274216 mscorwks!CallDescrWorkerWithHandler+0xd3
00000000`1a98f2c0 000007fe`f81c96a7 mscorwks!DispatchCallDebuggerWrapper+0×3e
00000000`1a98f320 000007fe`f830ae42 mscorwks!DispatchCallNoEH+0×5f
00000000`1a98f3a0 000007fe`f81bdc00 mscorwks!AddTimerCallback_Worker+0×92
00000000`1a98f430 000007fe`f82a41a5 mscorwks!ManagedThreadCallState::IsAppDomainEqual+0×4c
00000000`1a98f480 000007fe`f82df199 mscorwks!SVR::gc_heap::make_heap_segment+0×155
00000000`1a98f550 000007fe`f82ececa mscorwks!DoOpenIAssemblyStress::DoOpenIAssemblyStress+0×99
00000000`1a98f590 000007fe`f830c0db mscorwks!AddTimerCallbackEx+0xba
00000000`1a98f650 000007fe`f81ebb37 mscorwks!ThreadpoolMgr::AsyncTimerCallbackCompletion+0×53
00000000`1a98f6b0 000007fe`f81fe92a mscorwks!UnManagedPerAppDomainTPCount::DispatchWorkItem+0×157
00000000`1a98f750 000007fe`f81bb1fc mscorwks!ThreadpoolMgr::WorkerThreadStart+0×1ba
00000000`1a98f7f0 00000000`76e7652d mscorwks!Thread::intermediateThreadProc+0×78
00000000`1a98fcc0 00000000`76fac521 kernel32!BaseThreadInitThunk+0xd
00000000`1a98fcf0 00000000`00000000 ntdll!RtlUserThreadStart+0×1d

[...]

  15  Id: d50.7248 Suspend: 0 Teb: 000007ff`ffee6000 Unfrozen
Child-SP          RetAddr           Call Site
00000000`1c16e6f0 000007fe`f87946af mscorwks!AwareLock::Contention+0×13b
00000000`1c16e7c0 000007ff`0016135e mscorwks!JITutil_MonContention+0xdf
00000000`1c16e970 000007ff`0016726b 0×7ff`0016135e
00000000`1c16e9c0 000007fe`f74e2bbb 0×7ff`0016726b
00000000`1c16ea50 000007fe`f753ed76 mscorlib_ni+0×2f2bbb
00000000`1c16eaa0 000007fe`f8390282 mscorlib_ni+0×34ed76
00000000`1c16eaf0 000007fe`f8274363 mscorwks!CallDescrWorker+0×82
00000000`1c16eb40 000007fe`f8274216 mscorwks!CallDescrWorkerWithHandler+0xd3
00000000`1c16ebe0 000007fe`f81c96a7 mscorwks!DispatchCallDebuggerWrapper+0×3e
00000000`1c16ec40 000007fe`f830ae42 mscorwks!DispatchCallNoEH+0×5f
00000000`1c16ecc0 000007fe`f81bdc00 mscorwks!AddTimerCallback_Worker+0×92
00000000`1c16ed50 000007fe`f82a41a5 mscorwks!ManagedThreadCallState::IsAppDomainEqual+0×4c
00000000`1c16eda0 000007fe`f82df199 mscorwks!SVR::gc_heap::make_heap_segment+0×155
00000000`1c16ee70 000007fe`f82ececa mscorwks!DoOpenIAssemblyStress::DoOpenIAssemblyStress+0×99
00000000`1c16eeb0 000007fe`f830c0db mscorwks!AddTimerCallbackEx+0xba
00000000`1c16ef70 000007fe`f81ebb37 mscorwks!ThreadpoolMgr::AsyncTimerCallbackCompletion+0×53
00000000`1c16efd0 000007fe`f81fe92a mscorwks!UnManagedPerAppDomainTPCount::DispatchWorkItem+0×157
00000000`1c16f070 000007fe`f81bb1fc mscorwks!ThreadpoolMgr::WorkerThreadStart+0×1ba
00000000`1c16f110 00000000`76e7652d mscorwks!Thread::intermediateThreadProc+0×78
00000000`1c16f9e0 00000000`76fac521 kernel32!BaseThreadInitThunk+0xd
00000000`1c16fa10 00000000`00000000 ntdll!RtlUserThreadStart+0×1d

[...]

Thread #15 seems was caught at the time it was trying to enter and not waiting yet. If we check a monitor object the thread #12 tries to enter we see it has an address 01af0be8:

0:000> !u 000007ff`00161528
Normal JIT generated code
[…]
000007ff`00161505 90              nop
000007ff`00161506 48b8f089ae1100000000 mov rax,11AE89F0h
000007ff`00161510 488b00          mov     rax,qword ptr [rax]
000007ff`00161513 48894528        mov     qword ptr [rbp+28h],rax
000007ff`00161517 488b4528        mov     rax,qword ptr [rbp+28h]
000007ff`0016151b 48894518        mov     qword ptr [rbp+18h],rax
000007ff`0016151f 488b4d28        mov     rcx,qword ptr [rbp+28h]
000007ff`00161523 e8b8d422f8      call    mscorwks!JIT_MonEnter (000007fe`f838e9e0)
>>> 000007ff`00161528 90              nop
000007ff`00161529 90              nop
000007ff`0016152a 90              nop
[…]
000007ff`001615d2 4883c430        add     rsp,30h
000007ff`001615d6 5d              pop     rbp
000007ff`001615d7 f3c3            rep ret

0:000> dps 11AE89F0h l1
00000000`11ae89f0  00000000`01af0be8

This object seems to be owned by the thread #17:

0:000> !syncblk
Index         SyncBlock MonitorHeld Recursion Owning Thread Info          SyncBlock Owner
 1362 000000001ba7b6c0           15         1 000000001c0173b0  6854  17   0000000001af0be8 System.Object
[…]

This thread seems to be blocked in ALPC:

0:017> k
Child-SP          RetAddr           Call Site
00000000`1d55c9e8 000007fe`fee1a776 ntdll!NtAlpcSendWaitReceivePort+0xa
00000000`1d55c9f0 000007fe`fee14e42 rpcrt4!LRPC_CCALL::SendReceive+0x156
00000000`1d55cab0 000007fe`ff0828c0 rpcrt4!I_RpcSendReceive+0x42
00000000`1d55cae0 000007fe`ff08282f ole32!ThreadSendReceive+0x40
00000000`1d55cb30 000007fe`ff08265b ole32!CRpcChannelBuffer::SwitchAptAndDispatchCall+0xa3
00000000`1d55cbd0 000007fe`fef3daaa ole32!CRpcChannelBuffer::SendReceive2+0x11b
00000000`1d55cd90 000007fe`fef3da0c ole32!CAptRpcChnl::SendReceive+0x52
00000000`1d55ce60 000007fe`ff08205d ole32!CCtxComChnl::SendReceive+0x68
00000000`1d55cf10 000007fe`feebfd61 ole32!NdrExtpProxySendReceive+0x45
00000000`1d55cf40 000007fe`ff07f82f rpcrt4!NdrpClientCall2+0x9ea
00000000`1d55d6b0 000007fe`fef3d8a2 ole32!ObjectStublessClient+0x1ad
00000000`1d55da40 000007fe`fa511ba8 ole32!ObjectStubless+0x42
[...] 

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Learn from this Webinar about phenomenological, hermeneutical and analytical approaches to software diagnostics and its knowledge, foundations, norms, theories, logic, methodology, language, ontology, nature and truth. This seminar is hosted by Software Diagnostics Services.

Title: Introduction to Philosophy of Software Diagnostics
Date: 17th of December, 2012
Time: 19:00 GMT
Duration: 60 minutes

Space is limited.
Reserve your Webinar seat now at:
https://www3.gotomeeting.com/register/872846486

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

This is the first pattern that emerged after applying the same pattern-driven software diagnostics methodology to Mac OS X. I had problems using GDB which is so portable that hardly has operating system support like WinDbg has. Fortunately, I found a workaround by complementing core dumps with logs and reports from OS such as crash reports and vmmap data. I call this pattern Paratext which I borrowed from the concept of an extended software trace and software narratology where it borrowed the same concept from literary interpretation (paratext). Typical examples of such pattern usage can be the list of modules with version and path info, application crash specific information, memory region names with attribution and boundaries:

// from .crash reports

0x108f99000 - 0x109044ff7 com.apple.FontBook (198.4 - 198) <7244D36E-4563-3E42-BA46-1F279D30A6CE> /Applications/Font Book.app/Contents/MacOS/Font Book

Exception Type: EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes: 0x0000000000000001, 0x0000000000000000

Application Specific Information:
objc[195]: garbage collection is OFF
*** error for object 0x7fd7fb818e08: incorrect checksum for freed object - object was probably modified after being freed.

// from vmmap logs

[...]
==== Writable regions for process 966
[...]
Stack 0000000101f71000-0000000101ff3000 [ 520K] rw-/rwx SM=PRV thread 1
MALLOC_LARGE 0000000103998000-00000001039b8000 [ 128K] rw-/rwx SM=PRV DefaultMallocZone_0x101e6e000
MALLOC_SMALL (freed) 00000001039b9000-00000001039bb000 [ 8K] rw-/rwx SM=PRV
mapped file 0000000103a05000-0000000103f32000 [ 5300K] rw-/rwx SM=COW ...box.framework/Versions/A/Resources/Extras2.rsrc
mapped file 0000000104409000-00000001046d2000 [ 2852K] rw-/rwx SM=COW /System/Library/Fonts/Helvetica.dfont
MALLOC_LARGE 0000000104f6e000-0000000104f8e000 [ 128K] rw-/rwx SM=PRV DefaultMallocZone_0x101e6e000
MALLOC_LARGE (freed) 0000000108413000-0000000108540000 [ 1204K] rw-/rwx SM=COW
MALLOC_LARGE (freed) 0000000108540000-0000000108541000 [ 4K] rw-/rwx SM=PRV
MALLOC_TINY 00007fefe0c00000-00007fefe0d00000 [ 1024K] rw-/rwx SM=COW DefaultMallocZone_0x101e6e000
MALLOC_TINY 00007fefe0d00000-00007fefe0e00000 [ 1024K] rw-/rwx SM=PRV DispatchContinuations_0x101f38000
MALLOC_TINY 00007fefe0e00000-00007fefe0f00000 [ 1024K] rw-/rwx SM=COW DefaultMallocZone_0x101e6e000
MALLOC_SMALL 00007fefe1000000-00007fefe107b000 [ 492K] rw-/rwx SM=ZER DefaultMallocZone_0x101e6e000
MALLOC_SMALL 00007fefe107b000-00007fefe1083000 [ 32K] rw-/rwx SM=PRV DefaultMallocZone_0x101e6e000
MALLOC_SMALL 00007fefe1083000-00007fefe1149000 [ 792K] rw-/rwx SM=ZER DefaultMallocZone_0x101e6e000
MALLOC_SMALL (freed) 00007fefe1149000-00007fefe1166000 [ 116K] rw-/rwx SM=PRV DefaultMallocZone_0x101e6e000
MALLOC_SMALL (freed) 00007fefe1166000-00007fefe1800000 [ 6760K] rw-/rwx SM=ZER DefaultMallocZone_0x101e6e000
MALLOC_SMALL 00007fefe1800000-00007fefe18ff000 [ 1020K] rw-/rwx SM=ZER DefaultMallocZone_0x101e6e000
MALLOC_SMALL (freed) 00007fefe18ff000-00007fefe1901000 [ 8K] rw-/rwx SM=PRV DefaultMallocZone_0x101e6e000
MALLOC_SMALL 00007fefe1901000-00007fefe2000000 [ 7164K] rw-/rwx SM=ZER DefaultMallocZone_0x101e6e000
MALLOC_TINY (freed) 00007fefe2000000-00007fefe2100000 [ 1024K] rw-/rwx SM=PRV DispatchContinuations_0x101f38000
MALLOC_TINY 00007fefe2100000-00007fefe2200000 [ 1024K] rw-/rwx SM=PRV DefaultMallocZone_0x101e6e000
Stack 00007fff61186000-00007fff61985000 [ 8188K] rw-/rwx SM=ZER thread 0
Stack 00007fff61985000-00007fff61986000 [ 4K] rw-/rwx SM=COW
[...]

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -

Forthcoming Training: Accelerated Mac OS X Core Dump Analysis

A page to reference all different kinds of module and component related patterns is necessary, so I created this post:

• Duplicated Module
• Unloaded Module
• Module Variety
• Hidden Module
• Template Module
• Well-Tested Module
• Blocking Module
• Top Module
• Directing Module
• Module Hint
• Coupled Modules
• Problem Module
• Unknown Component
• No Component Symbols
• Missing Component (general)
• Missing Component (static linking, user mode)
• Ubiquitous Component (user space)
• Ubiquitous Component (kernel space)
• Nested Offender
• Effect Component
• Deviant Module
• Module Collection
• Module Product Process
• Module Collection (predicate)
• Dry Weight
• Exception Module
• Origin Module
• Hooked Modules
• Insufficient Memory (module fragmentation)
• Wait Chain (modules)
• Diachronic Module
• Foreign Module Frame
• Subsystem Modules

I’ll update it as soon as I add more similar patterns.

- Dmitry Vostokov @ DumpAnalysis.org + TraceAnalysis.org -