Re: [PATCH 3/3] elf/tst-dl_find_object: Disable subtests for non-contiguous maps (bug 28732)

["H.J. Lu" <hjl.tools@gmail.com>]

On Fri, Jan 14, 2022 at 7:10 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * H. J. Lu:
>
> > On Mon, Jan 3, 2022 at 9:13 AM Florian Weimer via Libc-alpha
> > <libc-alpha@sourceware.org> wrote:
> >>
> >> ---
> >>  elf/tst-dl_find_object.c | 29 +++++++++++++++++------------
> >>  1 file changed, 17 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/elf/tst-dl_find_object.c b/elf/tst-dl_find_object.c
> >> index 21cdc0f848..2ad1924088 100644
> >> --- a/elf/tst-dl_find_object.c
> >> +++ b/elf/tst-dl_find_object.c
> >> @@ -71,19 +71,24 @@ check (void *address,
> >>                __FILE__, line, address,
> >>                actual.dlfo_flags, expected->dlfo_flags);
> >>      }
> >> -  if (actual.dlfo_flags != expected->dlfo_flags)
> >> +  if (expected->dlfo_link_map->l_contiguous)
> >>      {
> >> -      support_record_failure ();
> >> -      printf ("%s:%d: error: %p: map start is %p, expected %p\n",
> >> -              __FILE__, line,
> >> -              address, actual.dlfo_map_start, expected->dlfo_map_start);
> >> -    }
> >> -  if (actual.dlfo_map_end != expected->dlfo_map_end)
> >> -    {
> >> -      support_record_failure ();
> >> -      printf ("%s:%d: error: %p: map end is %p, expected %p\n",
> >> -              __FILE__, line,
> >> -              address, actual.dlfo_map_end, expected->dlfo_map_end);
> >> +      /* If the mappings are not contiguous, the actual and execpted
> >> +         mappings may differ, so this subtest will not work.  */
> >> +      if (actual.dlfo_flags != expected->dlfo_flags)
> >> +        {
> >> +          support_record_failure ();
> >> +          printf ("%s:%d: error: %p: map start is %p, expected %p\n",
> >> +                  __FILE__, line,
> >> +                  address, actual.dlfo_map_start, expected->dlfo_map_start);
> >> +        }
> >> +      if (actual.dlfo_map_end != expected->dlfo_map_end)
> >> +        {
> >> +          support_record_failure ();
> >> +          printf ("%s:%d: error: %p: map end is %p, expected %p\n",
> >> +                  __FILE__, line,
> >> +                  address, actual.dlfo_map_end, expected->dlfo_map_end);
> >> +        }
> >>      }
> >>    if (actual.dlfo_link_map != expected->dlfo_link_map)
> >>      {
> >> --
> >> 2.33.1
> >>
> >
> > I still see
> >
> > FAIL: elf/tst-dl_find_object
> >
> > even when using the new linker with the fix for
> >
> > https://sourceware.org/bugzilla/show_bug.cgi?id=28743
> >
> > to remove the 1-page gap.  Which file doesn't have
> > non-contiguous mapping?
>
> We never set l_contiguous for the main executable, so it doesn't matter
> what the link editor does.  And none of the glibc fixes went in so far.
>
> Thanks,
> Florian
>

Should l_contiguous be set on the main executable? If not, why?

-- 
H.J.