[PATCH] perf/dwc_pcie: fix duplicate pci_dev devices

[Yunhui Cui]

During platform_device_register, wrongly using struct device
pci_dev as platform_data caused a kmemdup copy of pci_dev. Worse
still, accessing the duplicated device leads to list corruption as its
mutex content (e.g., list, magic) remains the same as the original.

Signed-off-by: Yunhui Cui <cuiyunhui@xxxxxxxxxxxxx>
---
 drivers/perf/dwc_pcie_pmu.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
index cccecae9823f..8b208f287a1f 100644
--- a/drivers/perf/dwc_pcie_pmu.c
+++ b/drivers/perf/dwc_pcie_pmu.c
@@ -565,9 +565,7 @@ static int dwc_pcie_register_dev(struct pci_dev *pdev)
 	u32 sbdf;
 
 	sbdf = (pci_domain_nr(pdev->bus) << 16) | PCI_DEVID(pdev->bus->number, pdev->devfn);
-	plat_dev = platform_device_register_data(NULL, "dwc_pcie_pmu", sbdf,
-						 pdev, sizeof(*pdev));
-
+	plat_dev = platform_device_register_simple("platform_dwc_pcie", sbdf, NULL, 0);
 	if (IS_ERR(plat_dev))
 		return PTR_ERR(plat_dev);
 
@@ -614,19 +612,32 @@ static struct notifier_block dwc_pcie_pmu_nb = {
 
 static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)
 {
-	struct pci_dev *pdev = plat_dev->dev.platform_data;
+	struct pci_dev *pdev = NULL;
 	struct dwc_pcie_pmu *pcie_pmu;
+	bool found = false;
 	char *name;
 	u32 sbdf;
 	u16 vsec;
 	int ret;
 
+	for_each_pci_dev(pdev) {
+		sbdf = (pci_domain_nr(pdev->bus) << 16) | PCI_DEVID(pdev->bus->number, pdev->devfn);
+		if (sbdf == plat_dev->id) {
+			found = true;
+			break;
+		}
+	}
+	if (!found) {
+		pr_err("The plat_dev->id does not match the sbdf");
+		return -ENODEV;
+	}
+
 	vsec = dwc_pcie_des_cap(pdev);
 	if (!vsec)
 		return -ENODEV;
 
 	sbdf = plat_dev->id;
-	name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
+	name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%d_pmu", sbdf);
 	if (!name)
 		return -ENOMEM;
 
@@ -640,7 +651,7 @@ static int dwc_pcie_pmu_probe(struct platform_device *plat_dev)
 	pcie_pmu->on_cpu = -1;
 	pcie_pmu->pmu = (struct pmu){
 		.name		= name,
-		.parent		= &pdev->dev,
+		.parent		= &plat_dev->dev,
 		.module		= THIS_MODULE,
 		.attr_groups	= dwc_pcie_attr_groups,
 		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
@@ -727,7 +738,7 @@ static int dwc_pcie_pmu_offline_cpu(unsigned int cpu, struct hlist_node *cpuhp_n
 
 static struct platform_driver dwc_pcie_pmu_driver = {
 	.probe = dwc_pcie_pmu_probe,
-	.driver = {.name = "dwc_pcie_pmu",},
+	.driver = {.name = "platform_dwc_pcie",},
 };
 
 static int __init dwc_pcie_pmu_init(void)
-- 
2.39.2