On Mon, Jun 29, 2020 at 09:20:31AM -0700, Kees Cook wrote: > On Mon, Jun 29, 2020 at 06:11:59PM +0200, Ard Biesheuvel wrote: > > On Mon, 29 Jun 2020 at 18:09, Kees Cook <keesc...@chromium.org> wrote: > > > > > > Should these be marked (INFO) as well? > > > > > > > Given that sections marked as (INFO) will still be emitted into the > > ELF image, it does not really make a difference to do this for zero > > sized sections. > > Oh, I misunderstood -- I though they were _not_ emitted; I see now what > you said was not allocated. So, disk space used for the .got.plt case, > but not memory space used. Sorry for the confusion! > > -Kees >
To confuse the issue a bit more, there are subtleties around "disk space used" :) The section will be present in the ELF format file, but at least on x86, that file is then converted into binary format via objcopy. At this point a non-allocated section at the end of the file will be stripped off. So on 32-bit x86, moving .got.plt to the end and marking it INFO will shave 16 bytes off the bzImage kernel.
