6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hao Chen chenhao418@huawei.com
[ 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@huawei.com Signed-off-by: Jijie Shao shaojijie@huawei.com Reviewed-by: Yicong Yang yangyicong@hisilicon.com Link: https://lore.kernel.org/r/20231019091352.998964-1-shaojijie@huawei.com [will: Rewrote commit message] Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/perf/hisilicon/hns3_pmu.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
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)