https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79341
--- Comment #46 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Or shall we use -mbackchain for -fsanitize=address by default and tweak the
unwinding code sanitizer_common/sanitizer_stacktrace.{cc,h} to use the
backchain?
AFAIK libsanitizer uses the .eh_frame unwinding for printing error dumps but
the fast unwinding (through frame pointer) by default when capturing backtraces
of malloc and free. Always using .eh_frame would be done by defining
SANITIZER_CAN_FAST_UNWIND to 0 in sanitizer_common/sanitizer_stacktrace.h if
__s390__ (e.g. sparc and mips do this). Wonder if LLVM emits backchain by
default or what.
