On 07.02.2024 11:46, Juergen Gross wrote:
> On 07.02.24 11:39, Jan Beulich wrote:
>> On 07.02.2024 11:31, Juergen Gross wrote:
>>> --- a/arch/x86/setup.c
>>> +++ b/arch/x86/setup.c
>>> @@ -184,6 +184,8 @@ arch_init(void *par)
>>> {
>>> static char hello[] = "Bootstrapping...\n";
>>>
>>> + memset(&__bss_start, 0, &_end - &__bss_start);
>>
>> Doesn't / shouldn't the loader guarantee this? I ask in particular
>> because doing this here implies earlier assembly code may not write
>> to any variable in .bss (nothing like that looks to exist right now,
>> but who knows what may be added at some point).
>
> Oh, am I misremembering that the hypervisor doesn't do the clearing?
>
> I do remember a bug when dom0 Linux crashed due to a not zeroed .bss,
> so I added the zeroing in the paravirt startup code of the kernel.
>
> But maybe this was due to a bug in the linker script of the kernel.
That's what I recall.
Jan
