On Mon, Jun 29, 2020 at 09:06:07AM -0700, Kees Cook wrote: > On Mon, Jun 29, 2020 at 10:09:27AM -0400, Arvind Sankar wrote: > > The BFD linker generates runtime relocations for z_input_len and > > z_output_len, even though they are absolute symbols. > > > > This is fixed for binutils-2.35 [1]. Work around this for earlier > > versions by defining two variables input_len and output_len in addition > > to the symbols, and use them via position-independent references. > > > > This eliminates the last two runtime relocations in the head code and > > allows us to drop the -z noreloc-overflow flag to the linker. > > > > [1] https://sourceware.org/bugzilla/show_bug.cgi?id=25754 > > > > Signed-off-by: Arvind Sankar <nived...@alum.mit.edu> > > Reviewed-by: Ard Biesheuvel <a...@kernel.org> > > Reviewed-by: Fangrui Song <mask...@google.com> > > --- > > arch/x86/boot/compressed/Makefile | 8 -------- > > arch/x86/boot/compressed/head_32.S | 17 ++++++++--------- > > arch/x86/boot/compressed/head_64.S | 4 ++-- > > arch/x86/boot/compressed/mkpiggy.c | 6 ++++++ > > 4 files changed, 16 insertions(+), 19 deletions(-) > > I continue to really enjoy the smaller code. Anything that makes > mkpiggy.c smaller is a win. :) > > Reviewed-by: Kees Cook <keesc...@chromium.org> > > -- > Kees Cook
It doesn't actually reduce the size? mkpiggy.c _could_ I think be replaced with some carefully written shell code, but this doesn't do anything like that.
