This is a note to let you know that I've just added the patch titled drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process to the 6.6-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: drivers-perf-hisi-use-cpuhp_state_remove_instance_no.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 687186ce1b6f5bf12065e322ffde89b607d40190 Author: Hao Chen <chenhao418@xxxxxxxxxx> Date: Thu Oct 19 17:13:52 2023 +0800 drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process [ Upstream commit 50b560783f7f71790bcf70e9e9855155fb0af8c1 ] When tearing down a 'hisi_hns3' PMU, we mistakenly run the CPU hotplug callbacks after the device has been unregistered, leading to fireworks when we try to execute empty function callbacks within the driver: | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 | CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G W O 5.12.0-rc4+ #1 | Hardware name: , BIOS KpxxxFPGA 1P B600 V143 04/22/2021 | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) | pc : perf_pmu_migrate_context+0x98/0x38c | lr : perf_pmu_migrate_context+0x94/0x38c | | Call trace: | perf_pmu_migrate_context+0x98/0x38c | hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu] Use cpuhp_state_remove_instance_nocalls() instead of cpuhp_state_remove_instance() so that the notifiers don't execute after the PMU device has been unregistered. Fixes: 66637ab137b4 ("drivers/perf: hisi: add driver for HNS3 PMU") Signed-off-by: Hao Chen <chenhao418@xxxxxxxxxx> Signed-off-by: Jijie Shao <shaojijie@xxxxxxxxxx> Reviewed-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20231019091352.998964-1-shaojijie@xxxxxxxxxx [will: Rewrote commit message] Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/perf/hisilicon/hns3_pmu.c b/drivers/perf/hisilicon/hns3_pmu.c index e0457d84af6b3..16869bf5bf4cc 100644 --- a/drivers/perf/hisilicon/hns3_pmu.c +++ b/drivers/perf/hisilicon/hns3_pmu.c @@ -1556,8 +1556,8 @@ static int hns3_pmu_init_pmu(struct pci_dev *pdev, struct hns3_pmu *hns3_pmu) ret = perf_pmu_register(&hns3_pmu->pmu, hns3_pmu->pmu.name, -1); if (ret) { pci_err(pdev, "failed to register perf PMU, ret = %d.\n", ret); - cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE, - &hns3_pmu->node); + cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE, + &hns3_pmu->node); } return ret; @@ -1568,8 +1568,8 @@ static void hns3_pmu_uninit_pmu(struct pci_dev *pdev) struct hns3_pmu *hns3_pmu = pci_get_drvdata(pdev); perf_pmu_unregister(&hns3_pmu->pmu); - cpuhp_state_remove_instance(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE, - &hns3_pmu->node); + cpuhp_state_remove_instance_nocalls(CPUHP_AP_PERF_ARM_HNS3_PMU_ONLINE, + &hns3_pmu->node); } static int hns3_pmu_init_dev(struct pci_dev *pdev)