AFLplusplus/qemu_mode/README.wine.md

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# How to troubleshoot AFL++'s wine mode
## 1) Debugging
To turn on wine debugging use the `WINEDEBUG` environment variable,
e.g. `WINEDEBUG=+timestamp,+tid,+loaddll`.
## 2) LoadLibraryA workaround
The forked process fails to load libraries loaded via `LoadLibrary`
if the load happens after the entry point (error code: 87). To resolve
this issue, one needs to load any external libraries before the fork happens.
An early DLL load can be achieved by adding the DLL name into the `Import Directory`
in the PE file. Such an entry can be added manually in any PE editor.
Alternativly, one can generate a `.lib` file from the DLL exports and link
them together with the harness to create an entry in the `Import Directory`.
Use `dumpbin /exports <filename>.dll` to extract the exports and paste the
exported function names into a `.def` file. Use `lib /def:<deffile> /OUT:<libfile>`
to generate a `.lib` and add the library to the linker options. Once the usage of
an export is detected (`__declspec(dllimport)`), the
linker adds the early DLL load.