This is a note to let you know that I've just added the patch titled perf/smmuv3: Fix hotplug callback leak in arm_smmu_pmu_init() to the 5.15-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-smmuv3-fix-hotplug-callback-leak-in-arm_smmu_pm.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 41f663ed5fe4474ac9c6f3ee53e2c0a460a02fe2 Author: Shang XiaoJing <shangxiaojing@xxxxxxxxxx> Date: Tue Nov 15 19:55:40 2022 +0800 perf/smmuv3: Fix hotplug callback leak in arm_smmu_pmu_init() [ Upstream commit 6f2d566b46436a50a80d6445e82879686b89588c ] arm_smmu_pmu_init() won't remove the callback added by cpuhp_setup_state_multi() when platform_driver_register() failed. Remove the callback by cpuhp_remove_multi_state() in fail path. Similar to the handling of arm_ccn_init() in commit 26242b330093 ("bus: arm-ccn: Prevent hotplug callback leak") Fixes: 7d839b4b9e00 ("perf/smmuv3: Add arm64 smmuv3 pmu driver") Signed-off-by: Shang XiaoJing <shangxiaojing@xxxxxxxxxx> Reviewed-by: Punit Agrawal <punit.agrawal@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221115115540.6245-3-shangxiaojing@xxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index 226348822ab3..5933ad151f86 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c @@ -896,6 +896,8 @@ static struct platform_driver smmu_pmu_driver = { static int __init arm_smmu_pmu_init(void) { + int ret; + cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "perf/arm/pmcg:online", NULL, @@ -903,7 +905,11 @@ static int __init arm_smmu_pmu_init(void) if (cpuhp_state_num < 0) return cpuhp_state_num; - return platform_driver_register(&smmu_pmu_driver); + ret = platform_driver_register(&smmu_pmu_driver); + if (ret) + cpuhp_remove_multi_state(cpuhp_state_num); + + return ret; } module_init(arm_smmu_pmu_init);