Re: [PATCH v3] Check the node argument passed to cpumask_of_node

From: Jesse Barnes
Date: Mon Jan 04 2010 - 12:18:57 EST


On Mon, 4 Jan 2010 20:28:57 +0530
David John <davidjon@xxxxxxxxxxx> wrote:

> Commit e0cd516 "PCI: derive nearby CPUs from device's instead of bus'
> NUMA information" causes an null pointer dereference when reading
> from the sysfs attributes local_cpu* on Intel machines with no ACPI
> NUMA proximity info, since dev->numa_node gets set to -1 for all PCI
> devices, which then gets passed to cpumask_of_node.
>
> Add a check to prevent this.
>
> Signed-off-by: David John <davidjon@xxxxxxxxxxx>
>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index c5df94e..807224e 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -75,7 +75,8 @@ static ssize_t local_cpus_show(struct device *dev,
> int len;
>
> #ifdef CONFIG_NUMA
> - mask = cpumask_of_node(dev_to_node(dev));
> + mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
> +
> cpumask_of_node(dev_to_node(dev)); #else
> mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
> #endif
> @@ -93,7 +94,8 @@ static ssize_t local_cpulist_show(struct device
> *dev, int len;
>
> #ifdef CONFIG_NUMA
> - mask = cpumask_of_node(dev_to_node(dev));
> + mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
> +
> cpumask_of_node(dev_to_node(dev)); #else
> mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
> #endif
>

Applied to my for-linus branch, thanks David.

--
Jesse Barnes, Intel Open Source Technology Center
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