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: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
drivers/gpu/vga/vgaarb.c | 15 +++------------
1 file changed, 3 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index 3df8fc0..b6852b7 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -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;
}
--
1.7.9.5
--
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