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Commit 017ffe64 authored by Yijing Wang's avatar Yijing Wang Committed by Bjorn Helgaas
Browse files

PCI: Hold pci_slot_mutex while searching bus->slots list 



Previously, pci_setup_device() and similar functions searched the
pci_bus->slots list without any locking.  It was possible for another
thread to update the list while we searched it.

Add pci_dev_assign_slot() to search the list while holding pci_slot_mutex.

[bhelgaas: changelog, fold in CONFIG_SYSFS fix]
Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarYijing Wang <wangyijing@huawei.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 67546762

arch/powerpc/kernel/pci_of_scan.c

+1 −5
Original line number Diff line number Diff line
@@ -126,7 +126,6 @@ struct pci_dev *of_create_pci_dev(struct device_node *node, 
{

	struct pci_dev *dev;

	const char *type;

	struct pci_slot *slot;



	dev = pci_alloc_dev(bus);

	if (!dev)
@@ -145,10 +144,7 @@ struct pci_dev *of_create_pci_dev(struct device_node *node, 
	dev->needs_freset = 0;		/* pcie fundamental reset required */

	set_pcie_port_type(dev);



	list_for_each_entry(slot, &dev->bus->slots, list)

		if (PCI_SLOT(dev->devfn) == slot->number)

			dev->slot = slot;



	pci_dev_assign_slot(dev);

	dev->vendor = get_int_prop(node, "vendor-id", 0xffff);

	dev->device = get_int_prop(node, "device-id", 0xffff);

	dev->subsystem_vendor = get_int_prop(node, "subsystem-vendor-id", 0);

arch/sparc/kernel/pci.c

+1 −5
Original line number Diff line number Diff line
@@ -249,7 +249,6 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm, 
					 struct pci_bus *bus, int devfn)

{

	struct dev_archdata *sd;

	struct pci_slot *slot;

	struct platform_device *op;

	struct pci_dev *dev;

	const char *type;
@@ -290,10 +289,7 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm, 
	dev->multifunction = 0;		/* maybe a lie? */

	set_pcie_port_type(dev);



	list_for_each_entry(slot, &dev->bus->slots, list)

		if (PCI_SLOT(dev->devfn) == slot->number)

			dev->slot = slot;



	pci_dev_assign_slot(dev);

	dev->vendor = of_getintprop_default(node, "vendor-id", 0xffff);

	dev->device = of_getintprop_default(node, "device-id", 0xffff);

	dev->subsystem_vendor =

drivers/pci/probe.c

+1 −5
Original line number Diff line number Diff line
@@ -1133,7 +1133,6 @@ int pci_setup_device(struct pci_dev *dev) 
{

	u32 class;

	u8 hdr_type;

	struct pci_slot *slot;

	int pos = 0;

	struct pci_bus_region region;

	struct resource *res;
@@ -1149,10 +1148,7 @@ int pci_setup_device(struct pci_dev *dev) 
	dev->error_state = pci_channel_io_normal;

	set_pcie_port_type(dev);



	list_for_each_entry(slot, &dev->bus->slots, list)

		if (PCI_SLOT(dev->devfn) == slot->number)

			dev->slot = slot;



	pci_dev_assign_slot(dev);

	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)

	   set this higher, assuming the system even supports it.  */

	dev->dma_mask = 0xffffffff;

drivers/pci/slot.c

+11 −0
Original line number Diff line number Diff line
@@ -194,6 +194,17 @@ static int rename_slot(struct pci_slot *slot, const char *name) 
	return result;

}



void pci_dev_assign_slot(struct pci_dev *dev)

{

	struct pci_slot *slot;



	mutex_lock(&pci_slot_mutex);

	list_for_each_entry(slot, &dev->bus->slots, list)

		if (PCI_SLOT(dev->devfn) == slot->number)

			dev->slot = slot;

	mutex_unlock(&pci_slot_mutex);

}



static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)

{

	struct pci_slot *slot;

include/linux/pci.h

+5 −0
Original line number Diff line number Diff line
@@ -798,6 +798,11 @@ struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr, 
				 const char *name,

				 struct hotplug_slot *hotplug);

void pci_destroy_slot(struct pci_slot *slot);

#ifdef CONFIG_SYSFS

void pci_dev_assign_slot(struct pci_dev *dev);

#else

static inline void pci_dev_assign_slot(struct pci_dev *dev) { }

#endif

int pci_scan_slot(struct pci_bus *bus, int devfn);

struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn);

void pci_device_add(struct pci_dev *dev, struct pci_bus *bus);