On Fri, Jan 25, 2019 at 5:17 AM Tom de Vries <tdevr...@suse.de> wrote: > > On 25-01-19 01:51, Ian Lance Taylor wrote: > > On Thu, Jan 24, 2019 at 4:11 PM Nathan Sidwell <nat...@acm.org> wrote: > >> > >> I just tripped over a segfault in libbacktrace. We apply strrchr to a > >> possibly NULL filename, with predictable results when it is. > >> > >> elf.c:3044 passes NULL as the filename parm: > >> ret = elf_add (state, NULL, d, base_address, error_callback, > >> data, > >> fileline_fn, found_sym, found_dwarf, NULL, 0, 1, > >> NULL, > >> 0); > >> > >> This gets to elf_open_debugfile_by_debuglink which passes it on through: > >> ddescriptor = elf_find_debugfile_by_debuglink (state, filename, > >> debuglink_name, > >> error_callback, data); > >> > >> this patch avoids the strrchr when filename is null. I reordered the > >> way prefix & prefix len got set, finding it prefereable to: > >> slash = filename ? NULL : strrchr (filename, '/'); > >> but if you prefer to avoid the assignment in the conditional I'm fine > >> with that too. > > > > Yeah, please don't do an assignment in a conditional. > > > > Why don't we just pass "" instead of NULL in the call to elf_add? If > > that works, that is OK. > > > > With this refactoring preamble ...
This is OK. Thanks. Ian
