RE: [PATCH V5] perf/x86: add sysfs entry to freeze counter on SMI

[Thomas Gleixner]

On Mon, 8 May 2017, Liang, Kan wrote:

> Hi tglx,
> 
> Are you OK with patch?
> Could I get your "acked-by"?

No.

> > > +static void flip_smm_bit(void *data)
> > > +{
> > > +	bool set = *(int *)data;

data points to an unsigned long. So while this works on LE machines this is
still crap.

> > > +	if (set) {
> > > +		msr_set_bit(MSR_IA32_DEBUGCTLMSR,
> > > +			    DEBUGCTLMSR_FREEZE_IN_SMM_BIT);
> > > +	} else {
> > > +		msr_clear_bit(MSR_IA32_DEBUGCTLMSR,
> > > +			      DEBUGCTLMSR_FREEZE_IN_SMM_BIT);
> > > +	}

I probably forgot, but why do we need an open coded version of __flip_bit()
instead of reusing that?

Thanks,

	tglx