diff options
Diffstat (limited to 'llvm_mode')
| -rw-r--r-- | llvm_mode/README.lto.md | 11 | ||||
| -rw-r--r-- | llvm_mode/afl-llvm-lto-instrim.so.cc | 3 |
2 files changed, 10 insertions, 4 deletions
diff --git a/llvm_mode/README.lto.md b/llvm_mode/README.lto.md index f930c560..fa5b8665 100644 --- a/llvm_mode/README.lto.md +++ b/llvm_mode/README.lto.md @@ -145,16 +145,21 @@ Known issues: Hence if building a target with afl-clang-lto fails try to build it with llvm11 and LTO enabled (`CC=clang-11` `CXX=clang++-11` `CFLAGS=-flto=full` and `CXXFLAGS=-flto=full`). + +An example that does not build with llvm 11 and LTO is ffmpeg. + If this succeeeds then there is an issue with afl-clang-lto. Please report at [https://github.com/AFLplusplus/AFLplusplus/issues/226](https://github.com/AFLplusplus/AFLplusplus/issues/226) ### Target crashes immediately -If the target is using early constructors (values smaller than 6) or have their -own _init/.init functions and these are instrumented then the target will -likely crash when started. This can be avoided by compiling with +If the target is using early constructors (priority values smaller than 6) +or have their own _init/.init functions and these are instrumented then the +target will likely crash when started. This can be avoided by compiling with `AFL_LLVM_MAP_DYNAMIC=1` . +This can e.g. happen with OpenSSL. + ## Upcoming Work 1. Currently the LTO whitelist feature does not allow to instrument main, diff --git a/llvm_mode/afl-llvm-lto-instrim.so.cc b/llvm_mode/afl-llvm-lto-instrim.so.cc index a686bb81..a7d9b756 100644 --- a/llvm_mode/afl-llvm-lto-instrim.so.cc +++ b/llvm_mode/afl-llvm-lto-instrim.so.cc @@ -10,7 +10,8 @@ http://www.apache.org/licenses/LICENSE-2.0 - This library is plugged into LLVM when invoking clang through afl-clang-fast. + This library is plugged into LLVM when invoking clang through afl-clang-fast + or afl-clang-lto with AFL_LLVM_INSTRUMENT=CFG or =INSTRIM */ |