Re: [PATCH v2 2/4] pc-bios/s390-ccw: Provide space for initial stack frame in start.S

[Philippe Mathieu-Daudé]

On 27/6/23 10:26, Marc Hartmayer wrote:
> Thomas Huth <thuth@redhat.com> writes:
>
> > Providing the space of a stack frame is the duty of the caller,
> > so we should reserve 160 bytes before jumping into the main function.
> > Otherwise the main() function might write past the stack array.
> >
> > While we're at it, add a proper STACK_SIZE macro for the stack size
> > instead of using magic numbers (this is also required for the following
> > patch).
> >
> > Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
> > Reviewed-by: Cédric Le Goater <clg@redhat.com>
> > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > ---
> >   pc-bios/s390-ccw/start.S | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)


> > +#define STACK_SIZE 0x8000
> > +
> >       .globl _start
> >   _start:
> >   
> > -    larl    %r15,stack + 0x8000     /* Set up stack */
> > +    larl    %r15,stack + STACK_SIZE - 160   /* Set up stack */
>                                           ^^^
>                                           You can also add a macro for this
>                                           - e.g. STACK_FRAME_SIZE.

Yes please :) No need to respin.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> Besides that,
> Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
=