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Patch "perf/x86/intel/cstate: Prevent hotplug callback leak" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Jan 6, 2017

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This is a note to let you know that I've just added the patch titled

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

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
perf-x86-intel-cstate-prevent-hotplug-callback-leak.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 834fcd298003c10ce450e66960c78893cb1cc4b5 Mon Sep 17 00:00:00 2001

From: Thomas Gleixner <[email protected]>
Date: Thu, 22 Dec 2016 11:02:08 +0100
Subject: perf/x86/intel/cstate: Prevent hotplug callback leak

From: Thomas Gleixner <[email protected]>

commit 834fcd298003c10ce450e66960c78893cb1cc4b5 upstream.

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 <[email protected]>
Cc Sebastian Siewior <[email protected]>
Cc Peter Zijlstra <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 arch/x86/events/intel/cstate.c |   14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)
arch/x86/events/intel/cstate.c +7 -7
@@ -594,6 +594,9 @@ static int __init cstate_probe(const str
 
 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);

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/timekeeping_force_unsigned_clocksource_to_nanoseconds_conversion.patch queue-4.9/perf-x86-fix-exclusion-of-bts-and-lbr-for-goldmont.patch queue-4.9/perf-x86-intel-cstate-prevent-hotplug-callback-leak.patch