Re: [PATCH v3] x86/boot: discard .eh_frame sections

[Nick Desaulniers]

Bumping for review (I couldn't find if this was merged already in tip/tip)

On Tue, Nov 26, 2019 at 9:16 AM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> On Tue, Nov 26, 2019 at 6:46 AM Ilie Halip <ilie.halip@xxxxxxxxx> wrote:
> >
> > When using GCC as compiler and LLVM's lld as linker, linking
> > setup.elf fails:
> >       LD      arch/x86/boot/setup.elf
> >     ld.lld: error: init sections too big!
> >
> > This happens because GCC generates .eh_frame sections for most
> > of the files in that directory, then ld.lld places the merged
> > section before __end_init, triggering an assert in the linker
> > script.
> >
> > Fix this by discarding the .eh_frame sections, as suggested by
> > Boris. The kernel proper linker script discards them too.
> >
> > Signed-off-by: Ilie Halip <ilie.halip@xxxxxxxxx>
> > Link: https://lore.kernel.org/lkml/20191118175223.GM6363@xxxxxxx/
> > Link: https://github.com/ClangBuiltLinux/linux/issues/760
> > Suggested-by: Borislav Petkov <bp@xxxxxxxxx>
>
> Ilie, thanks for following up with a v3.
> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>
> > ---
> >
> > Changes in V3:
> >  * discard .eh_frame instead of placing it after .rodata
> >
> > Changes in V2:
> >  * removed wildcard for input sections (.eh_frame* -> .eh_frame)
> >
> >  arch/x86/boot/setup.ld | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/boot/setup.ld b/arch/x86/boot/setup.ld
> > index 0149e41d42c2..3da1c37c6dd5 100644
> > --- a/arch/x86/boot/setup.ld
> > +++ b/arch/x86/boot/setup.ld
> > @@ -51,7 +51,10 @@ SECTIONS
> >         . = ALIGN(16);
> >         _end = .;
> >
> > -       /DISCARD/ : { *(.note*) }
> > +       /DISCARD/       : {
> > +               *(.eh_frame)
> > +               *(.note*)
> > +       }
> >
> >         /*
> >          * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
> > --
> > 2.17.1
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers



-- 
Thanks,
~Nick Desaulniers