6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hao Chen <chenhao418@xxxxxxxxxx>
[ 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>
---
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)
--
2.42.0
