Re: [Patch v2 6/9] perf/x86/intel: Validate return value of intel_pmu_init_hybrid()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Unnecessary error handling logic for memory allocation failure in early boot (__init) function
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commit 3dd0c7770a2df131c0ee92d24ad34bc579754b8e
Author: Dapeng Mi <dapeng1.mi@linux.intel.com>

perf/x86/intel: Validate return value of intel_pmu_init_hybrid()

This commit adds checks for the return value of intel_pmu_init_hybrid()
to prevent accessing the uninitialized x86_pmu.hybrid_pmu[] array on
allocation failure. It also introduces an error path to free the created
task_ctx_cache kmem cache if this failure occurs.

> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index 532a089e16762..57b1a4bd3facf 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c

[ ... ]

> @@ -8540,7 +8541,9 @@ __init int intel_pmu_init(void)
>  		 *
>  		 * Initialize the common PerfMon capabilities here.
>  		 */
> -		intel_pmu_init_hybrid(hybrid_big_small);
> +		ret = intel_pmu_init_hybrid(hybrid_big_small);
> +		if (ret < 0)
> +			goto err;

[ ... ]

> @@ -8886,6 +8901,10 @@ __init int intel_pmu_init(void)
>  	intel_aux_output_init();
>  
>  	return 0;
> +
> +err:
> +	kmem_cache_destroy(x86_get_pmu(smp_processor_id())->task_ctx_cache);
> +	return ret;
>  }

[Severity: Low]
Is this cleanup logic necessary for an __init function? 

Memory allocation failures during early boot generally mean the system cannot
boot anyway. Functions executed only at this stage typically do not need to
handle memory allocation failures gracefully, making this kind of error
handling and cleanup logic effectively dead code.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260609050222.2458129-1-dapeng1.mi@linux.intel.com?part=6