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Diffstat (limited to 'qemu_mode')
| -rw-r--r-- | qemu_mode/README.wine.md | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/qemu_mode/README.wine.md b/qemu_mode/README.wine.md new file mode 100644 index 00000000..567901cd --- /dev/null +++ b/qemu_mode/README.wine.md @@ -0,0 +1,21 @@ +# 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. \ No newline at end of file |