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[PATCH v2 2/2] perf/dwc_pcie: fix duplicate pci_dev devices

Yunhui Cui posted 2 patches 1 year ago
There is a newer version of this series
[PATCH v2 2/2] perf/dwc_pcie: fix duplicate pci_dev devices
Posted by Yunhui Cui 1 year ago 
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@bytedance.com>
---
 drivers/perf/dwc_pcie_pmu.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
index 4ac53167d7ab..fd9d87b4f201 100644
--- a/drivers/perf/dwc_pcie_pmu.c
+++ b/drivers/perf/dwc_pcie_pmu.c
@@ -566,9 +566,7 @@ 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);
 
@@ -620,18 +618,26 @@ 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;
 	struct dwc_pcie_pmu *pcie_pmu;
 	char *name;
 	u32 sbdf;
 	u16 vsec;
 	int ret;
 
+	sbdf = plat_dev->id;
+	pdev = pci_get_domain_bus_and_slot(sbdf >> 16, PCI_BUS_NUM(sbdf & 0xffff),
+					   sbdf & 0xff);
+	if (!pdev) {
+		pr_err("No pdev found for the sbdf");
+		return -ENODEV;
+	}
+
 	vsec = dwc_pcie_des_cap(pdev);
 	if (!vsec)
 		return -ENODEV;
 
-	sbdf = plat_dev->id;
+	pci_dev_put(pdev);
 	name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
 	if (!name)
 		return -ENOMEM;
@@ -646,7 +652,7 @@ 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,
@@ -733,7 +739,7 @@ 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 void dwc_pcie_cleanup_devices(void)
-- 
2.39.2
Re: [PATCH v2 2/2] perf/dwc_pcie: fix duplicate pci_dev devices
Posted by Shuai Xue 1 year ago 

在 2025/2/5 11:14, Yunhui Cui 写道:
> 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@bytedance.com>
> ---
>   drivers/perf/dwc_pcie_pmu.c | 20 +++++++++++++-------
>   1 file changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
> index 4ac53167d7ab..fd9d87b4f201 100644
> --- a/drivers/perf/dwc_pcie_pmu.c
> +++ b/drivers/perf/dwc_pcie_pmu.c
> @@ -566,9 +566,7 @@ 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);
>   
> @@ -620,18 +618,26 @@ 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;
>   	struct dwc_pcie_pmu *pcie_pmu;
>   	char *name;
>   	u32 sbdf;
>   	u16 vsec;
>   	int ret;
>   
> +	sbdf = plat_dev->id;
> +	pdev = pci_get_domain_bus_and_slot(sbdf >> 16, PCI_BUS_NUM(sbdf & 0xffff),
> +					   sbdf & 0xff);
> +	if (!pdev) {
> +		pr_err("No pdev found for the sbdf");

How about also adding the sbdf to print?

> +		return -ENODEV;
> +	}
> +
>   	vsec = dwc_pcie_des_cap(pdev);
>   	if (!vsec)
>   		return -ENODEV;
>   
> -	sbdf = plat_dev->id;
> +	pci_dev_put(pdev);
>   	name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
>   	if (!name)
>   		return -ENOMEM;
> @@ -646,7 +652,7 @@ 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,
> @@ -733,7 +739,7 @@ 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 void dwc_pcie_cleanup_devices(void)
Re: [External] Re: [PATCH v2 2/2] perf/dwc_pcie: fix duplicate pci_dev devices
Posted by yunhui cui 1 year ago 
Hi Shuai,

On Fri, Feb 7, 2025 at 10:36 AM Shuai Xue <xueshuai@linux.alibaba.com> wrote:
>
>
>
> 在 2025/2/5 11:14, Yunhui Cui 写道:
> > 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@bytedance.com>
> > ---
> >   drivers/perf/dwc_pcie_pmu.c | 20 +++++++++++++-------
> >   1 file changed, 13 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
> > index 4ac53167d7ab..fd9d87b4f201 100644
> > --- a/drivers/perf/dwc_pcie_pmu.c
> > +++ b/drivers/perf/dwc_pcie_pmu.c
> > @@ -566,9 +566,7 @@ 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);
> >
> > @@ -620,18 +618,26 @@ 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;
> >       struct dwc_pcie_pmu *pcie_pmu;
> >       char *name;
> >       u32 sbdf;
> >       u16 vsec;
> >       int ret;
> >
> > +     sbdf = plat_dev->id;
> > +     pdev = pci_get_domain_bus_and_slot(sbdf >> 16, PCI_BUS_NUM(sbdf & 0xffff),
> > +                                        sbdf & 0xff);
> > +     if (!pdev) {
> > +             pr_err("No pdev found for the sbdf");
>
> How about also adding the sbdf to print?
OK, I'll update to v3.

>
> > +             return -ENODEV;
> > +     }
> > +
> >       vsec = dwc_pcie_des_cap(pdev);
> >       if (!vsec)
> >               return -ENODEV;
> >
> > -     sbdf = plat_dev->id;
> > +     pci_dev_put(pdev);
> >       name = devm_kasprintf(&plat_dev->dev, GFP_KERNEL, "dwc_rootport_%x", sbdf);
> >       if (!name)
> >               return -ENOMEM;
> > @@ -646,7 +652,7 @@ 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,
> > @@ -733,7 +739,7 @@ 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 void dwc_pcie_cleanup_devices(void)
>

Thanks,
Yunhui

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