[PATCH 5/6] drm/i915/uc: Reject duplicate entries in firmware table

[Ceraolo Spurio, Daniele]

On 4/20/2023 6:15 PM, John.C.Harrison at Intel.com wrote:
> From: John Harrison <John.C.Harrison at Intel.com>
>
> It was noticed that duplicate entries in the firmware table could cause
> an infinite loop in the firmware loading code if that entry failed to
> load. Duplicate entries are a bug anyway and so should never happen.
> Ensure they don't by tweaking the table validation code to reject
> duplicates.
>
> For full m/m/p files, that can be done by simply tweaking the patch
> level check to reject matching values. For reduced version entries,
> the filename itself must be compared.
>
> Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
> ---
>   drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 27 +++++++++++++++++++++---
>   1 file changed, 24 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> index eb52e8db9ae0b..bc4011d55667c 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c
> @@ -319,7 +319,7 @@ static bool validate_fw_table_type(struct drm_i915_private *i915, enum intel_uc_
>   {
>   	const struct uc_fw_platform_requirement *fw_blobs;
>   	u32 fw_count;
> -	int i;
> +	int i, j;
>   
>   	if (type >= ARRAY_SIZE(blobs_all)) {
>   		drm_err(&i915->drm, "No blob array for %s\n", intel_uc_fw_type_repr(type));
> @@ -334,6 +334,27 @@ static bool validate_fw_table_type(struct drm_i915_private *i915, enum intel_uc_
>   
>   	/* make sure the list is ordered as expected */
>   	for (i = 1; i < fw_count; i++) {
> +		/* Versionless file names must be unique per platform: */
> +		for (j = i + 1; j < fw_count; j++) {
> +			/* Same platform? */
> +			if (fw_blobs[i].p != fw_blobs[j].p)
> +				continue;
> +
> +			if (fw_blobs[i].blob.path != fw_blobs[j].blob.path)
> +				continue;
> +
> +			drm_err(&i915->drm, "Diplicaate %s blobs: %s r%u %s%d.%d.%d [%s] matches %s r%u %s%d.%d.%d [%s]\n",

typo Diplicaate

> +				intel_uc_fw_type_repr(type),
> +				intel_platform_name(fw_blobs[j].p), fw_blobs[j].rev,
> +				fw_blobs[j].blob.legacy ? "L" : "v",
> +				fw_blobs[j].blob.major, fw_blobs[j].blob.minor,
> +				fw_blobs[j].blob.patch, fw_blobs[j].blob.path,
> +				intel_platform_name(fw_blobs[i].p), fw_blobs[i].rev,

nit: we could avoid printing the platform twice because you're 
explicitly checking that it is the same earlier on. Not a blocked.
With the typo fixed:

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Daniele

> +				fw_blobs[i].blob.legacy ? "L" : "v",
> +				fw_blobs[i].blob.major, fw_blobs[i].blob.minor,
> +				fw_blobs[i].blob.patch, fw_blobs[i].blob.path);
> +		}
> +
>   		/* Next platform is good: */
>   		if (fw_blobs[i].p < fw_blobs[i - 1].p)
>   			continue;
> @@ -377,8 +398,8 @@ static bool validate_fw_table_type(struct drm_i915_private *i915, enum intel_uc_
>   		if (fw_blobs[i].blob.minor != fw_blobs[i - 1].blob.minor)
>   			goto bad;
>   
> -		/* Patch versions must be in order: */
> -		if (fw_blobs[i].blob.patch <= fw_blobs[i - 1].blob.patch)
> +		/* Patch versions must be in order and unique: */
> +		if (fw_blobs[i].blob.patch < fw_blobs[i - 1].blob.patch)
>   			continue;
>   
>   bad: