Re: [Patch v8 01/23] 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:
- [Medium] The patch introduces new early returns on `intel_pmu_init_hybrid()` failure, which leaks previously allocated resources such as the LBR kmem_cache.
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commit a727042ce1ace4502dce4dc723479df37ff50da5
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()
in intel_pmu_init() to prevent attempts to access an uninitialized
x86_pmu.hybrid_pmu[] array if memory allocation fails.

> diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
> index 0217e701aeebb..85c329bd52be3 100644
> --- a/arch/x86/events/intel/core.c
> +++ b/arch/x86/events/intel/core.c
[ ... ]
> @@ -8545,7 +8546,9 @@ __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)
> +			return ret;

[Severity: Medium]
Does returning early here leak the LBR kmem_cache?

Earlier in intel_pmu_init(), if the CPU supports it, the LBR cache is
allocated:

	if (boot_cpu_has(X86_FEATURE_ARCH_LBR))
		intel_pmu_arch_lbr_init();

When intel_pmu_init() returns an error, its caller init_hw_perf_events()
will zero out the global x86_pmu struct, but it doesn't appear to call
kmem_cache_destroy() on the newly allocated task_ctx_cache. Could this
leave the cache leaked?

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260529075645.580362-1-dapeng1.mi@linux.intel.com?part=1