drcov: empty log-file is generated when the target app crashes under fuzzing

Created by: shakibrezapor

Describe the bug an empty log file is generated when the target application crashes.

I’m running the below command to execute a 32-bit application (on Windows 10): <<bin32\drrun.exe -t drcov -dump_text --example.exe>>

It starts working, and executing the "example.exe", and keep running till the target app crashes under fuzzing, the log file (drcov.example.exe.17264.0000.proc.log) is also generated, but the log file is empty (zero kb).

However, if the app exits normally (e.g. CTRL+C) and dont crashes, then the generated log file is fine and not empty

To Reproduce Run the below command: bin32\drrun.exe -t drcov -dump_text --example.exe

Please also answer these questions:

• What happens when you run without any client? this is not clear to me

• What happens when you run with debug build ("-debug" flag to drrun/drconfig/drinject)? debug generated result as below: <Application tried to execute from unreadable memory 0x41414141. This may be a result of an unsuccessful attack or a potential application vulnerability.>

Expected behavior a log file which is not empty

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Versions

• What version of DynamoRIO are you using? 8.0.18494
• Does the latest build from https://github.com/DynamoRIO/dynamorio/wiki/Latest-Build solve the problem? No
• What operating system version are you running on? ("Windows 10" is not sufficient: give the release number.) Win 10 build 15063
• Is your application 32-bit or 64-bit? 32-bit

Additional context Add any other context about the problem here.