Re: [PATCH V2 5/9] tools/arch/x86/intel_sdsi: Fix maximum meter bundle length

From: Kuppuswamy Sathyanarayanan
Date: Tue Feb 27 2024 - 21:54:27 EST



On 2/27/24 4:00 PM, David E. Box wrote:
> The maximum number of bundles in the meter certificate was set to 8 which
> is much less than the maximum. Instead, since the bundles appear at the end
> of the file, set it based on the remaining file size from the bundle start
> position.
>
> Fixes: aad129780bae ("platform/x86/intel/sdsi: Add support for reading the current meter state")
> Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
> ---
>
> V2 - Split of V1 patch 7
>
> tools/arch/x86/intel_sdsi/intel_sdsi.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/tools/arch/x86/intel_sdsi/intel_sdsi.c b/tools/arch/x86/intel_sdsi/intel_sdsi.c
> index 2cd92761f171..a02850a710ee 100644
> --- a/tools/arch/x86/intel_sdsi/intel_sdsi.c
> +++ b/tools/arch/x86/intel_sdsi/intel_sdsi.c
> @@ -43,7 +43,6 @@
> #define METER_CERT_MAX_SIZE 4096
> #define STATE_MAX_NUM_LICENSES 16
> #define STATE_MAX_NUM_IN_BUNDLE (uint32_t)8
> -#define METER_MAX_NUM_BUNDLES 8
>
> #define __round_mask(x, y) ((__typeof__(x))((y) - 1))
> #define round_up(x, y) ((((x) - 1) | __round_mask(x, y)) + 1)
> @@ -167,6 +166,9 @@ struct bundle_encoding_counter {
> uint32_t encoding;
> uint32_t counter;
> };
> +#define METER_MAX_NUM_BUNDLES \
> + ((METER_CERT_MAX_SIZE - sizeof(struct meter_certificate)) / \
> + sizeof(struct bundle_encoding_counter))
>
> struct sdsi_dev {
> struct sdsi_regs regs;
> @@ -387,7 +389,7 @@ static int sdsi_meter_cert_show(struct sdsi_dev *s)
> }
>
> if (mc->bundle_length > METER_MAX_NUM_BUNDLES * 8) {
> - fprintf(stderr, "More than %d bundles: %d\n",
> + fprintf(stderr, "More than %ld bundles: actual %d\n",
> METER_MAX_NUM_BUNDLES, mc->bundle_length / 8);

I think you can avoid hardcoding here as well. sizeof(struct bundle_encoding_counter)

> return -1;
> }

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer