diff --git a/docs/ASAN-notes.txt b/docs/ASAN-notes.txt new file mode 100644 index 0000000..759e29e --- /dev/null +++ b/docs/ASAN-notes.txt @@ -0,0 +1,60 @@ +/* + * This document explain how to run analyse the virglrenderer + * code base using ASAN, the address sanitizer tools include + * in Clang and gcc. + */ + +VIRGLRENDERER: + +Compiling virglrenderer with the following flags: +`-fsanitize=address` +or +`-fsanitize=memory` +Sadly, we can't use both of them in the same time. + +For example, +``` +export CFLAGS="-fsanitize=address -fno-omit-frame-pointer" +export CXXFLAGS="-fsanitize=address -fno-omit-frame-pointer" +mkdir build && cd build +../autogen.sh --prefix=/home/user/virglrenderer/install --enable-debug +make +``` + +The `-fsanitize=leak` flag don't have to be add for Linux as +it is set by default. This flag can be add to the toolchain of other platform. + + +MESA: + +Since mesa unloads the drivers before a program finished, but ASAN only +resolves stack traces at the end. It is almost impossible to get meaningful +backtraces and so check whether the culprit is mesa or virglrenderer. +Hence, it is useful to override *dlclose* by pre-loading a shared library +that implements a stub, e.g. like: +``` +int dlclose(void *handle) { + return 0; +} +``` +It seems that you need to pre-load ASAN before your dummie library. +`export LD_PRELOAD="/usr/lib64/gcc/x86_64-pc-linux-gnu/7.3.0/libasan.so $HOME/libfake-dlclose.so"` + + +VTEST: + +Then run virglrenderer with the following flag: +`ASAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer` +On platform other than Linux, `ASAN_OPTIONS=detect_leaks=1` +should be added. + +Start the vtest server with the command: +`ASAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer ./virgl_test_server` + +Then connect to the server +``` +export LIBGL_ALWAYS_SOFTWARE=true +export GALLIUM_DRIVER=virpipe +``` + +Run any payload.