Re: [PATCH] x86: Don't clare __force_order in kaslr_64.c

From: H.J. Lu
Date: Fri Jan 24 2020 - 13:39:51 EST


On Fri, Jan 24, 2020 at 10:24 AM Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
>
>
> > On Jan 24, 2020, at 10:18 AM, H.J. Lu <hjl.tools@xxxxxxxxx> wrote:
> >
> > ïGCC 10 changed the default to -fno-common, which leads to
> >
> > LD arch/x86/boot/compressed/vmlinux
> > ld: arch/x86/boot/compressed/pgtable_64.o:(.bss+0x0): multiple definition of `__force_order'; arch/x86/boot/compressed/kaslr_64.o:(.bss+0x0): first defined here
> > make[2]: *** [arch/x86/boot/compressed/Makefile:119: arch/x86/boot/compressed/vmlinux] Error 1
> >
> > Since __force_order is already provided in pgtable_64.c, there is no
> > need to declare __force_order in kaslr_64.c.
>
> Why does anything actually define that variable? Surely any actual references are just an outright bug. Is it needed for LTO?

It is needed by GCC 10 without LTO.

--
H.J.