Re: [PATCH 3/4] pc-bios/s390-ccw: Move the stack array into start.S

[Thomas Huth]

On 26/06/2023 17.25, Richard Henderson wrote:
> On 6/26/23 16:54, Christian Borntraeger wrote:
> > Am 26.06.23 um 15:21 schrieb Thomas Huth:
> >
> > > diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S
> > > index 29b0a9ece0..47ef6e8aa8 100644
> > > --- a/pc-bios/s390-ccw/start.S
> > > +++ b/pc-bios/s390-ccw/start.S
> > > @@ -120,3 +120,8 @@ external_new_mask:
> > >       .quad   0x0000000180000000
> > >   io_new_mask:
> > >       .quad   0x0000000180000000
> > > +
> > > +.bss
> > > +
> > > +    .align  16
> > > +    .lcomm  stack,STACK_SIZE
> >
> > IIRC, the ELF ABI defines the stack to be 8 byte aligned, but 16 certainly 
> > does not hurt.
>
> This doesn't do what you think it does.
>
> .lcomm produces a COMMON symbol, which is merged with .bss at link time.  
> Thus the .align does nothing.  Even switching to .bss section does nothing 
> here.
>
> You want
>
> .bss
>      .align 16
> stack:
>      .space    STACK_SIZE
>      .size    stack, STACK_SIZE

Oh, thanks! I'll fix it in v2.

 Thomas