PCI: Fix reference counting bug (c4ed02fa) · Commits · 戴 / test

pci_get_subsys() will decrement the reference count of the device that it starts searching from. Unfortunately, the pci_find_device() interface will already have decremented the reference count of the device earlier, so the device will end up losing all reference counts and be freed. We can fix this by incrementing the reference count of the device to start searching from before calling pci_get_subsys(). Signed-off-by:

Matthew Wilcox <willy@linux.intel.com> Signed-off-by:

Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/search.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -166,6 +166,7 @@ struct pci_dev *pci_find_device(unsigned int vendor, unsigned int device,
		{
		struct pci_dev *pdev;

		pci_dev_get(from);
		pdev = pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
		pci_dev_put(pdev);
		return pdev;
		@@ -270,12 +271,8 @@ static struct pci_dev pci_get_dev_by_id(const struct pci_device_id id,
		struct pci_dev *pdev = NULL;

		WARN_ON(in_interrupt());
		if (from) {
		/* FIXME
		* take the cast off, when bus_find_device is made const.
		*/
		dev_start = (struct device *)&from->dev;
		}
		if (from)
		dev_start = &from->dev;
		dev = bus_find_device(&pci_bus_type, dev_start, (void *)id,
		match_pci_dev_by_id);
		if (dev)

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