Re: [PATCH v2] tools/power turbostat: Fix RAPL summary collection on AMD processors

[Borislav Petkov]

On Fri, Apr 23, 2021 at 08:16:07PM +0800, Chen Yu wrote:
> From b2e63fe4f02e17289414b4f61237da822df115fb Mon Sep 17 00:00:00 2001
> From: Calvin Walton <calvin.walton@xxxxxxxxxx>
> Date: Fri, 23 Apr 2021 17:32:13 +0800
> Subject: [PATCH 3/5] tools/power turbostat: Fix offset overflow issue in index
>  converting
> 
> The idx_to_offset() function returns type int (32-bit signed), but
> MSR_PKG_ENERGY_STAT is greater than INT_MAX (or rather, would be
> interpreted as a negative number). The end result is that it hits
> the if (offset < 0) check in update_msr_sum() resulting in the timer
> callback for updating the stat in the background when long durations
> are used to not happen. The similar issue exists in offset_to_idx()
> and update_msr_sum().
> 
> This patch fixes this issue by converting the 'int' type to 'off_t'
> accordingly.
> 
> Fixes: 9972d5d84d76 ("tools/power turbostat: Enable accumulate RAPL display")
> Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>

This patch's authorship is weird: it says From: Calvin but doesn't have
his SOB here - only yours.

> ---
>  tools/power/x86/turbostat/turbostat.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
> index a211264b57fd..77557122b292 100644
> --- a/tools/power/x86/turbostat/turbostat.c
> +++ b/tools/power/x86/turbostat/turbostat.c
> @@ -296,9 +296,9 @@ struct msr_sum_array {
>  /* The percpu MSR sum array.*/
>  struct msr_sum_array *per_cpu_msr_sum;
>  
> -int idx_to_offset(int idx)
> +off_t idx_to_offset(int idx)

And this is silly. MSRs are unsigned int. Fullstop.

So that function should either return u32 or unsigned int or so.

Thx.

-- 
Regards/Gruss,
    Boris.

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