Re: [Xen-devel] [PATCH v3 1/3] xen/x86: replace '||' usage in the linker script

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Thu, Jul 12, 2018 at 01:38:21PM +0200, Daniel Kiper wrote:
> On Wed, Jul 11, 2018 at 05:34:48PM +0200, Roger Pau Monne wrote:
> > With '|'. The result is the same, and the later works with lld. Fixes
> > the following error when building Xen with lld:
> >
> > ld    -melf_x86_64_fbsd  -T xen.lds -N prelink.o --build-id=sha1 \
> >     /root/src/xen/xen/common/symbols-dummy.o -o 
> > /root/src/xen/xen/.xen-syms.0
> > ld: error: xen.lds:260: malformed number: |
> > >>> ASSERT(__image_base__ > (((((((((261 >> 8) * 0xffff000000000000) | (261 
> > >>> << 39))) + ((1 << 39) / 2)) + (64 << 30)) + (1 << 30)) + (1 << 30))) ||
> > >>>                                                                         
> > >>>                                                                       ^
> >
> > Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> > ---
> > Cc: Jan Beulich <jbeulich@xxxxxxxx>
> > Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> > Cc: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
> > ---
> >  xen/arch/x86/xen.lds.S | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
> > index 70afedd31d..326e885402 100644
> > --- a/xen/arch/x86/xen.lds.S
> > +++ b/xen/arch/x86/xen.lds.S
> > @@ -331,7 +331,7 @@ SECTIONS
> >    .comment 0 : { *(.comment) }
> >  }
> >
> > -ASSERT(__image_base__ > XEN_VIRT_START ||
> > +ASSERT(__image_base__ > XEN_VIRT_START |
> >         __2M_rwdata_end <= XEN_VIRT_END - NR_CPUS * PAGE_SIZE,
> >         "Xen image overlaps stubs area")
> 
> I am not happy with this change. Is the same needed for any "&&"?

I haven't tried, but I assume both '||' and '&&' would be equally
broken. There's no '&&' ATM anyway.

> Anyway, if maintainers are OK with that I will just ask you to put
> the comment before the ASSERT() why you use "|" instead of "||".

OK, I can add something like:

"lld (LLVM linker) version 6.0.0 doesn't support '||', so use '|'
instead."

Thanks, Roger.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel