http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59410
--- Comment #11 from Kostya Serebryany <kcc at gcc dot gnu.org> --- > 555555554000-555555555000 r-xp 00000000 08:11 34221424 > /export/build/gnu/gcc-x32/build-x86_64-linux/gcc/testsuite/atomic_stack.exe So, the executable is loaded into 555555554000, which intersects with tsan's shadow. See tsan/rtl/tsan_platform.h, around "C++ linux memory layout". In our experience this happens when ASLR is off. And this is caused by the kernel patch I mentioned above. https://code.google.com/p/thread-sanitizer/wiki/CppManual?ts=1386348951&updated=CppManual#FAQ We have not seen other reason for such mapping, maybe you know one :)