[Patch v8 01/23] perf/x86/intel: Validate return value of intel_pmu_init_hybrid()

[Dapeng Mi]

The memory allocation for the x86_pmu.hybrid_pmu[] array in
intel_pmu_init_hybrid() can theoretically fail due to memory shortages.
If this occurs, the initialization of the x86 hybrid PMU would fail.

Currently, the code does not check the return value of the
intel_pmu_init_hybrid() function, which could lead to attempts to access
the uninitialized x86_pmu.hybrid_pmu[] array, potentially causing a
system panic.

So, adds a check for the return value of intel_pmu_init_hybrid() to
prevent invalid memory access in such scenarios.

Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---

V8: New patch.

 arch/x86/events/intel/core.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 0217e701aeeb..85c329bd52be 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -7870,6 +7870,7 @@ __init int intel_pmu_init(void)
 	int version, i;
 	char *name;
 	struct x86_hybrid_pmu *pmu;
+	int ret;
 
 	/* Architectural Perfmon was introduced starting with Core "Yonah" */
 	if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
@@ -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;
 
 		x86_pmu.pebs_latency_data = grt_latency_data;
 		x86_pmu.get_event_constraints = adl_get_event_constraints;
@@ -8603,7 +8606,9 @@ __init int intel_pmu_init(void)
 	case INTEL_METEORLAKE:
 	case INTEL_METEORLAKE_L:
 	case INTEL_ARROWLAKE_U:
-		intel_pmu_init_hybrid(hybrid_big_small);
+		ret = intel_pmu_init_hybrid(hybrid_big_small);
+		if (ret < 0)
+			return ret;
 
 		x86_pmu.pebs_latency_data = cmt_latency_data;
 		x86_pmu.get_event_constraints = mtl_get_event_constraints;
@@ -8634,7 +8639,9 @@ __init int intel_pmu_init(void)
 		pr_cont("Pantherlake Hybrid events, ");
 		name = "pantherlake_hybrid";
 
-		intel_pmu_init_hybrid(hybrid_big_small);
+		ret = intel_pmu_init_hybrid(hybrid_big_small);
+		if (ret < 0)
+			return ret;
 
 		/* Initialize big core specific PerfMon capabilities.*/
 		pmu = &x86_pmu.hybrid_pmu[X86_HYBRID_PMU_CORE_IDX];
@@ -8649,7 +8656,9 @@ __init int intel_pmu_init(void)
 		pr_cont("Arrowlake Hybrid events, ");
 		name = "arrowlake_hybrid";
 
-		intel_pmu_init_hybrid(hybrid_big_small);
+		ret = intel_pmu_init_hybrid(hybrid_big_small);
+		if (ret < 0)
+			return ret;
 
 		/* Initialize big core specific PerfMon capabilities.*/
 		pmu = &x86_pmu.hybrid_pmu[X86_HYBRID_PMU_CORE_IDX];
@@ -8666,7 +8675,9 @@ __init int intel_pmu_init(void)
 		pr_cont("Lunarlake Hybrid events, ");
 		name = "lunarlake_hybrid";
 
-		intel_pmu_init_hybrid(hybrid_big_small);
+		ret = intel_pmu_init_hybrid(hybrid_big_small);
+		if (ret < 0)
+			return ret;
 
 		/* Initialize big core specific PerfMon capabilities.*/
 		pmu = &x86_pmu.hybrid_pmu[X86_HYBRID_PMU_CORE_IDX];
@@ -8691,7 +8702,9 @@ __init int intel_pmu_init(void)
 		break;
 
 	case INTEL_ARROWLAKE_H:
-		intel_pmu_init_hybrid(hybrid_big_small_tiny);
+		ret = intel_pmu_init_hybrid(hybrid_big_small_tiny);
+		if (ret < 0)
+			return ret;
 
 		x86_pmu.pebs_latency_data = arl_h_latency_data;
 		x86_pmu.get_event_constraints = arl_h_get_event_constraints;
@@ -8726,7 +8739,9 @@ __init int intel_pmu_init(void)
 	case INTEL_NOVALAKE_L:
 		pr_cont("Novalake Hybrid events, ");
 		name = "novalake_hybrid";
-		intel_pmu_init_hybrid(hybrid_big_small);
+		ret = intel_pmu_init_hybrid(hybrid_big_small);
+		if (ret < 0)
+			return ret;
 
 		x86_pmu.pebs_latency_data = nvl_latency_data;
 		x86_pmu.get_event_constraints = mtl_get_event_constraints;
-- 
2.34.1