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

[Richard Henderson]

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


r~