On Thu, 2012-04-12 at 15:22 -0700, Josh Stone wrote: > I'm seeing a segfault in your debugtypes.exp test added to systemtap, > with my poor unpatched elfutils-0.153 on F16. The call to > dwarf_offdie_types is returning NULL, which the calling code is not > prepared for. > > So is the NULL return the extent of the failure? Or is elfutils > generally borked after that? > > And even apart from this bug, should we be ready for NULL return from > dwarf_offdie_types() anyway? Same question for dwarf_offdie(), I guess.
NULL can be returned fir dwarf_offdie () or dwarf_offdie_types () when you give an offset that isn't really a DIE offset inside the debug_info or debug_types section or when invalid DWARF is encountered. In such cases NULL is returned and dwarf_errno () is set. The bug was in the code that associated the right CU or TU with the returned Dwarf_Die. The CU/TU is cached, but before the bug the cache could become bad and then even valid offsets could fail, but the bug only impacted dwarf_offdie_types (). Cheers, Mark _______________________________________________ elfutils-devel mailing list [email protected] https://fedorahosted.org/mailman/listinfo/elfutils-devel
