Re: [PATCH] hyperv: fix build if KEXEC not enabled

[Vitaly Kuznetsov <vkuznets@redhat.com>]

Ingo Molnar <mingo@kernel.org> writes:

> * Stephen Hemminger <stephen@networkplumber.org> wrote:
>
>> Fixes regression 4.3 mergw window in my config 
>> where hyperv is enable but CONFIG_KEXEC not enabled.
>> 
>> arch/x86/kernel/cpu/mshyperv.c:112: undefined reference to `native_machine_crash_shutdown'
>> 
>> Introduced by:
>>    commit b4370df2b1f5158de028e167974263c5757b34a6
>>    Author: Vitaly Kuznetsov <vkuznets@redhat.com>
>>    Date:   Sat Aug 1 16:08:09 2015 -0700
>> 
>>        Drivers: hv: vmbus: add special crash handler
>> 
>> 
>> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
>> 
>> 
>> --- a/arch/x86/kernel/cpu/mshyperv.c	2015-09-07 10:11:24.994885115 -0700
>> +++ b/arch/x86/kernel/cpu/mshyperv.c	2015-09-07 10:14:20.995698615 -0700
>> @@ -109,7 +109,9 @@ static void hv_machine_crash_shutdown(st
>>  {
>>  	if (hv_crash_handler)
>>  		hv_crash_handler(regs);
>> +#ifdef CONFIG_KEXEC
>>  	native_machine_crash_shutdown(regs);
>> +#endif
>
> I think there's another related bug as well:
>
>         machine_ops.crash_shutdown = hv_machine_crash_shutdown;
>
> that should be #ifdef CONFIG_KEXEC as well AFAICS.
>

Why? crash_shutdown is defined in machine_ops unconditionally, I don't
see why we _need_ #ifdef here (and btw Greg insisted on removing them).

> These bugs came upstream via the driver tree:
>
>  b4370df2b1f5 ("Drivers: hv: vmbus: add special crash handler")
>  2517281d63a2 ("Drivers: hv: vmbus: add special kexec handler")
>
> Thanks,
>
> 	Ingo

-- 
  Vitaly