Re: [PATCH 1/9] xen/arm: Check Xen size when linking

[Julien Grall <julien@xxxxxxx>]

Hi Michal,

On 26/06/2023 12:24, Michal Orzel wrote:
> On 25/06/2023 22:48, Julien Grall wrote:
> > The linker will happily link Xen if it is bigger than what we can handle
> > (e.g 2MB). This will result to unexpected failure after boot.
> >
> > This unexpected failure can be prevented by forbidding linking if Xen is
> > bigger than the area we reversed.
> s/reversed/reserved
>
> > Signed-off-by: Julien Grall <julien@xxxxxxx>
> > ---
> >   xen/arch/arm/xen.lds.S | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> > index be58c2c39514..c5d8c6201423 100644
> > --- a/xen/arch/arm/xen.lds.S
> > +++ b/xen/arch/arm/xen.lds.S
> > @@ -241,3 +241,4 @@ ASSERT(IS_ALIGNED(__init_begin,     4), "__init_begin is 
> > misaligned")
> >   ASSERT(IS_ALIGNED(__init_end,       4), "__init_end is misaligned")
> >   ASSERT(IS_ALIGNED(__bss_start,      POINTER_ALIGN), "__bss_start is 
> > misaligned")
> >   ASSERT(IS_ALIGNED(__bss_end,        POINTER_ALIGN), "__bss_end is misaligned")
> > +ASSERT((_end - start) <= XEN_VIRT_SIZE, "Xen is too big")
> Would it be possible to use _start so that we can have a consolidated way of 
> calculating xen size
> across arch linker scripts and C code? It makes it easier for grepping.
Fair point. I have renamed to _start.

> All in all,
> Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
Thanks!

Cheers,

--
Julien Grall