WinDBG cheat sheet

Prereqs

Examining the unmanaged environment

• .load sos mscorwks (This command load the sos debugger extension)
• .loadby sos mscorwks
• .dump /mA (filepath) (This command generates a full memory dump)
• ~*k (This command lists all call stacks from all threads)
• ~* e !clrstack (This command dumps all clr stack. This is to show how to execute a command against all threads.))
• dqs (Addr) + 120 (This command shows word and symbols. Use dds (Addr) + 120 for 32bit)
• dc (Addr)
• .chain (Show you all the extensions in the order. Only to check debug extensions are loaded correctly)
• ~20s (This command switches to thread 20.)
• lmf (lists all loaded modules with the full path)
• lmt (lists all loaded modules with the last modified timestamp)
• ~ list (lists unmanaged threads)
• ~thread s (select a thread s for executing thread specific commands)
• !token -n (view the thread permissions)
• k (view unmanaged call stack)
• !runaway (view CPU consumption for the thread)
• bp (set a breakpoint)
• .dump path (dump the small memory image)
• .dump /ma path (dump the complete memory image)
• !heap (list the heaps with index and the heap address)

Managed commands (assumes SOS is available)

• !dae (This command lists all exceptions)
• !waitlist (This command shows waitlist. May be useful to look at hangs or long waits)
• !handle (This command shows handle. May be useful to looking at handle leaks)
• !htrace (Trace handle leak. http://channel9.msdn.com/Blogs/jeff_dailey/Understanding-handle-leaks-and-how-to-use-htrace-to-find-them )
• !dso (see what objects the thread owns. Useful in finding where memory is allocated.)
• !do (dump object array)
• !cce (Check current exception)
• !analyze –v (This command does analysis and tells you what it thinks is wrong. Generate a lot of files. But this is usually useless in user mode debugger.)

Debug managed memory leak

• !dumpdomain (This command list the assemblies. Look for unknown domains for dynamically loaded assemblies)
• !EEHeap (This command gets a summary of CLR memory)
• !DumpHeap –stat
• !gcroot <object address>

References

• http://windbg.info/doc/1-common-cmds.html
• http://en.wikipedia.org/wiki/WinDbg

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