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Commit f85567c8 authored by Jiang Liu's avatar Jiang Liu Committed by Bjorn Helgaas
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PCI/vga: Use hotplug-safe pci_get_domain_bus_and_slot() 



Following code has a race window between pci_find_bus() and pci_get_slot()
if PCI hotplug operation happens between them which removes the pci_bus.
So use PCI hotplug safe interface pci_get_domain_bus_and_slot() instead,
which also reduces code complexity.

    struct pci_bus *pci_bus = pci_find_bus(domain, busno);
    struct pci_dev *pci_dev = pci_get_slot(pci_bus, devfn);

Signed-off-by: default avatarJiang Liu <jiang.liu@huawei.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent ddec11b1

drivers/gpu/vga/vgaarb.c

+3 −12
Original line number Diff line number Diff line
@@ -1066,7 +1066,6 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf, 
		}



	} else if (strncmp(curr_pos, "target ", 7) == 0) {

		struct pci_bus *pbus;

		unsigned int domain, bus, devfn;

		struct vga_device *vgadev;
@@ -1085,19 +1084,11 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf, 
			pr_debug("vgaarb: %s ==> %x:%x:%x.%x\n", curr_pos,

				domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));



			pbus = pci_find_bus(domain, bus);

			pr_debug("vgaarb: pbus %p\n", pbus);

			if (pbus == NULL) {

				pr_err("vgaarb: invalid PCI domain and/or bus address %x:%x\n",

					domain, bus);

				ret_val = -ENODEV;

				goto done;

			}

			pdev = pci_get_slot(pbus, devfn);

			pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);

			pr_debug("vgaarb: pdev %p\n", pdev);

			if (!pdev) {

				pr_err("vgaarb: invalid PCI address %x:%x\n",

					bus, devfn);

				pr_err("vgaarb: invalid PCI address %x:%x:%x\n",

					domain, bus, devfn);

				ret_val = -ENODEV;

				goto done;

			}