Hello Stefan,
On Thu, 02 Aug 2012 10:23:13 +0200
Stefan Bader <stefan.bader at canonical.com> wrote:
> > static void
> > adjust_member_offset(Dwarf_Die *die)
> > {
> > long offset;
> >
> > if (dwarf_info.member_offset == NOT_FOUND_STRUCTURE) // this comparison is always true
> > return;
> > if (!get_data_member_location(die, &offset))
> > return;
> > dwarf_info.member_offset += offset;
> > }
> >
> > At least, the change below works fine without regression.
> >
> >
> > diff --git a/dwarf_info.c b/dwarf_info.c
> > index 583df53..03e4c90 100644
> > --- a/dwarf_info.c
> > +++ b/dwarf_info.c
> > @@ -520,7 +520,9 @@ search_member(Dwarf_Die *die)
> > /*
> > * Get the member offset.
> > */
> > - if (!get_data_member_location(walker, &offset))
> > + if (dwarf_tag(die) == DW_TAG_union_type)
>
> Hm, should that not be die_type to check what the walker is on? And in that case
> it seems that check was made just before... So maybe it would be ok to assume 0
> as the offset when getting here...?
As you said, the walker will be a member of union or struct when reaching here,
because is_anonymous_container() already checked the walker.
However, get_data_member_location() must succeed if the walker is a member of struct
while it doesn't succeed if the walker is a member of union.
That's why I added the code to check whether the walker is a member of union or not.
Thanks
Atsushi Kumagai
> > + offset = 0;
> > + else if (!get_data_member_location(walker, &offset))
> > continue;
> > dwarf_info.member_offset = offset;
> > return TRUE;
> >
> >
> > Unless you have better way to fix this issue, I'll merge your patch into
> > the next version with the change above.
> >
> > By the way, this fix enable us also to get the offset of page._mapcount and
> > page.private, it's very helpful for the new method of free page filtering.
> >
> > http://lists.infradead.org/pipermail/kexec/2012-June/006441.html
> >
> >
> > Thanks
> > Atsushi Kumagai
> >
>
>
