perf/x86/intel/cstate: Prevent hotplug callback leak

If the pmu registration fails the registered hotplug callbacks are not
removed. Wrong in any case, but fatal in case of a modular driver.

Replace the nonsensical state names with proper ones while at it.

Fixes: 77c34ef1c319 ("perf/x86/intel/cstate: Convert Intel CSTATE to hotplug state machine")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org

diff --git a/arch/x86/events/intel/cstate.c b/arch/x86/events/intel/cstate.c
index da51e5a..fec8a46 100644 (file)
--- a/arch/x86/events/intel/cstate.c
+++ b/arch/x86/events/intel/cstate.c
@@ -594,6 +594,9 @@ static int __init cstate_probe(const struct cstate_model *cm)
 
 static inline void cstate_cleanup(void)
 {
+       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_ONLINE);
+       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_STARTING);
+
        if (has_cstate_core)
                perf_pmu_unregister(&cstate_core_pmu);
 
@@ -606,16 +609,16 @@ static int __init cstate_init(void)
        int err;
 
        cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_STARTING,
-                         "AP_PERF_X86_CSTATE_STARTING", cstate_cpu_init,
-                         NULL);
+                         "perf/x86/cstate:starting", cstate_cpu_init, NULL);
        cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_ONLINE,
-                         "AP_PERF_X86_CSTATE_ONLINE", NULL, cstate_cpu_exit);
+                         "perf/x86/cstate:online", NULL, cstate_cpu_exit);
 
        if (has_cstate_core) {
                err = perf_pmu_register(&cstate_core_pmu, cstate_core_pmu.name, -1);
                if (err) {
                        has_cstate_core = false;
                        pr_info("Failed to register cstate core pmu\n");
+                       cstate_cleanup();
                        return err;
                }
        }
@@ -629,8 +632,7 @@ static int __init cstate_init(void)
                        return err;
                }
        }
-
-       return err;
+       return 0;
 }
 
 static int __init cstate_pmu_init(void)
@@ -655,8 +657,6 @@ module_init(cstate_pmu_init);
 
 static void __exit cstate_pmu_exit(void)
 {
-       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_ONLINE);
-       cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_STARTING);
        cstate_cleanup();
 }
 module_exit(cstate_pmu_exit);