Re: [PATCH] x86/pmstat: correct PMSTAT_get_pxstat buffer size checking

[Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>]

On Mon, Jun 16, 2025 at 1:00 PM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> min(pmpt->perf.state_count, op->u.getpx.total) == op->u.getpx.total can
> be expressed differently as pmpt->perf.state_count >= op->u.getpx.total.
> Copying when the two are equal is fine; (partial) copying when the state
> count is larger than the number of array elements that a buffer was
> allocated to hold is what - as per the comment - we mean to avoid. Drop
> the use of min() again, but retain its effect for the subsequent copying
> from pxpt->u.pt.
>
> Fixes: aa70996a6896 ("x86/pmstat: Check size of PMSTAT_get_pxstat buffers")
> Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>

Reviewed-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

Thanks,
Ross