https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79341
--- Comment #47 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Seems clang doesn't default to -mbackchain for -fsanitize=address, they just force it on when testing: if config.target_arch == 's390x': clang_asan_static_cflags.append("-mbackchain") So, if we just want to go that route, we could add to deep-stack-uaf-1.C // { dg-additional-options "-mbackchain" { target { s390*-*-* } } } It is of course not very kind to users that would need to add it manually if they want accurate backtraces for malloc/free.