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Commit fc87e919 authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Jesse Barnes
Browse files

PCI ASPM: fix possible null pointer dereference 



Fix possible NULL dereference in pcie_aspm_exit_link_state(). This
patch also cleanup some code.

Acked-by: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 8a339e73

drivers/pci/pcie/aspm.c

+9 −8
Original line number Original line Diff line number Diff line
@@ -665,16 +665,16 @@ out: 
void pcie_aspm_exit_link_state(struct pci_dev *pdev)

void pcie_aspm_exit_link_state(struct pci_dev *pdev)

{

{

	struct pci_dev *parent = pdev->bus->self;

	struct pci_dev *parent = pdev->bus->self;

	struct pcie_link_state *link_state = parent->link_state;

	struct pcie_link_state *link;





	if (aspm_disabled || !pdev->is_pcie || !parent || !link_state)

	if (aspm_disabled || !pdev->is_pcie || !parent || !parent->link_state)

		return;

		return;

	if (parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&

	if (parent->pcie_type != PCI_EXP_TYPE_ROOT_PORT &&

	    parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)

	    parent->pcie_type != PCI_EXP_TYPE_DOWNSTREAM)

		return;

		return;



	down_read(&pci_bus_sem);

	down_read(&pci_bus_sem);

	mutex_lock(&aspm_lock);

	mutex_lock(&aspm_lock);



	/*

	/*

	 * All PCIe functions are in one slot, remove one function will remove

	 * All PCIe functions are in one slot, remove one function will remove

	 * the whole slot, so just wait until we are the last function left.

	 * the whole slot, so just wait until we are the last function left.
@@ -682,13 +682,14 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev) 
	if (!list_is_last(&pdev->bus_list, &parent->subordinate->devices))

	if (!list_is_last(&pdev->bus_list, &parent->subordinate->devices))

		goto out;

		goto out;





	link = parent->link_state;



	/* All functions are removed, so just disable ASPM for the link */

	/* All functions are removed, so just disable ASPM for the link */

	__pcie_aspm_config_one_dev(parent, 0);

	__pcie_aspm_config_one_dev(parent, 0);

	list_del(&link_state->sibling);

	list_del(&link->sibling);

	list_del(&link_state->link);

	list_del(&link->link);

	/* Clock PM is for endpoint device */

	/* Clock PM is for endpoint device */



	free_link_state(link);

	free_link_state(link_state);

out:

out:

	mutex_unlock(&aspm_lock);

	mutex_unlock(&aspm_lock);

	up_read(&pci_bus_sem);

	up_read(&pci_bus_sem);