Re: [PATCH] perf/dwc_pcie: fix duplicate pci_dev devices
From: Shuai Xue <xueshuai@linux.alibaba.com>
Date: 2025-01-23 09:50:00
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在 2025/1/23 15:48, Yunhui Cui 写道:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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; + } +
How about using pci_get_domain_bus_and_slot() to find pci_dev?
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);
A new name will break previous user tools.
quoted hunk ↗ jump to hunk
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)
Thanks. Best Regards, Shuai