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

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

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>
=