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From:   Jijie Shao <shaojijie@huawei.com>
To:     <will@kernel.org>, <jonathan.cameron@huawei.com>,
        <mark.rutland@arm.com>, <yangyicong@hisilicon.com>
CC:     <shaojijie@huawei.com>, <chenhao418@huawei.com>,
        <shenjian15@huawei.com>, <wangjie125@huawei.com>,
        <liuyonglong@huawei.com>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>
Subject: [PATCH V3 drivers/perf: hisi:] drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process
Date:   Thu, 19 Oct 2023 17:13:52 +0800
Message-ID: <20231019091352.998964-1-shaojijie@huawei.com>
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From: Hao Chen <chenhao418@huawei.com>

For pmu uninit process, we unregister pmu and then call cpuhp_state_remove_instance()
to call callback function to migrate pmu context. the logic is unreasonable and
may result in NULL pointer call trace.

Found NULL pointer call trace for kernel-5.12 at the first time, log shows as below:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[27169.471153] Mem abort info:
[27169.478859]   ESR = 0x96000006
[27169.485117]   EC = 0x25: DABT (current EL), IL = 32 bits
[27169.501386]   SET = 0, FnV = 0
[27169.508038]   EA = 0, S1PTW = 0
[27169.559839] Data abort info:
[27169.567296]   ISV = 0, ISS = 0x00000006
[27169.585332]   CM = 0, WnR = 0
[27169.592627] user pgtable: 4k pages, 48-bit VAs, pgdp=00000820ac0c2000
[27169.615618] [0000000000000000] pgd=00000820af2bf003, p4d=00000820af2bf003, pud=00000820af2bd003, pmd=0000000000000000
[27169.641348] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[27169.649879] Modules linked in: hisi_hns3_pmu(-) hns3 hclge hclgevf hnae3 hns3_cae(O) vfio_iommu_type1 vfio_pci vfio_virqfd vfio pv680_mii(O) [last unloaded: hisi_hns3_pmu]
[27169.675150] CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G        W  O      5.12.0-rc4+ #1
[27169.686538] Hardware name:  , BIOS KpxxxFPGA 1P B600 V143 04/22/2021
[27169.694884] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
[27169.704199] pc : perf_pmu_migrate_context+0x98/0x38c
[27169.713848] lr : perf_pmu_migrate_context+0x94/0x38c
[27169.723069] sp : ffff80001020bc80
[27169.727938] x29: ffff80001020bc80 x28: 0000000000000000
[27169.737236] x27: 0000000000000001 x26: fffffbffeff951d8
[27169.745245] x25: ffffb7ae1ce36fd0 x24: fffffbffeff95178
[27169.753116] x23: ffff0821f6f82668 x22: 0000000000000001
[27169.760949] x21: ffff80001020bd08 x20: fffffbffeffb5188
[27169.768467] x19: fffffbffeffb5178 x18: 0000000000000020
[27169.776699] x17: 0000000000000000 x16: 0000000000000000
[27169.785042] x15: 0000000000000004 x14: ffff08208093d290
[27169.793254] x13: 0000000000000000 x12: 0000497f0149bafe
[27169.801390] x11: 01262d2f8bbfdccc x10: 3dc70ddec1e5f4f9
[27169.808896] x9 : ffffb7ae1a7eb108 x8 : 0000000000000002
[27169.817000] x7 : 0000000000000000 x6 : 000000000000000e
[27169.824726] x5 : 0000000000000001 x4 : 0000000000000000
[27169.832924] x3 : 0000000000000000 x2 : ffff082080a30e80
[27169.841135] x1 : 0000000000000000 x0 : fffffbffeffb5188
[27169.849059] Call trace:
[27169.853177]  perf_pmu_migrate_context+0x98/0x38c
[27169.862256]  hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu]
[27169.873943]  cpuhp_invoke_callback+0x118/0x634
[27169.882775]  cpuhp_thread_fun+0xe8/0x190
[27169.890345]  smpboot_thread_fn+0x25c/0x290
[27169.898241]  kthread+0x168/0x16c
[27169.904178]  ret_from_fork+0x10/0x18
[27169.911943] Code: 944beda1 aa1403e0 944bed9f f8460f5c (f9400394)

And tested some other uncore pmu driver such as hisi_pcie_pmu and hisi_uncore_l3c_pmu,
hisi_pcie_pmu driver can reproduce it also, and change hisi_uncore_l3c_pmu hotplug
function from cpuhp_state_remove_instance_nocalls() to cpuhp_state_remove_instance(),
it has the same call trace.

This patch change cpuhp_state_remove_instance() to cpuhp_state_remove_instance_nocalls()
after pmu unregistered to fix the problem.

This problem is fixed by commit bd2756811766 ("perf: Rewrite core context handling")
for kernel-6.2.

Hisi_hns3_pmu driver is supported for kernel-5.19, so, use this patch as bugfix for
stable 6.0 and 6.1 tag, and use this patch as cleanup for newest kernel version.

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>
---
ChangeLog:
V2->V3:
	1. Format the name of pmu driver suggested by Yicong
	V2: https://lore.kernel.org/all/20231016105139.1436425-1-shaojijie@huawei.com/
V1->V2:
	1. Add more details for NULL pointer call trace suggested by Yicong
	V1: https://lore.kernel.org/all/20231009105038.126040-1-shaojijie@huawei.com/
---
 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 e0457d84af6b..16869bf5bf4c 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)
-- 
2.30.0