Re: [PATCH v2 4/5] perf/amd/ibs: Avoid calling perf_allow_kernel() from the IBS NMI handler

[Michael Petlan]

On Mon, 9 Mar 2026, Ravi Bangoria wrote:
> Hi Michael,
> 
> > By evaluating the privileges at the event-init moment and using cached
> > value later, couldn't it lead to the cached value being obsolete at
> > some point? E.g. a setuid program later dropping the privileges but
> > still being able to read physical addresses?
> 
> Yes, but wouldn't the same concern apply to all other call sites of
> perf_allow_kernel() ?

Well, I don't say this case is worse than the others, just raising a
more generic question whether this design is fairly acceptable or would
deserve e.g. privilege adjusting at the time when they are dropped or
something... Nothing more, just a note... :)

Michael
> 
> Thanks,
> Ravi
> 
>