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: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/arch/powerpc/kernel/pci_of_scan.c b/arch/powerpc/kernel/pci_of_scan.c
index 42e02a2..5e2debf 100644
--- a/arch/powerpc/kernel/pci_of_scan.c
+++ b/arch/powerpc/kernel/pci_of_scan.c
@@ -126,7 +126,6 @@
{
struct pci_dev *dev;
const char *type;
- struct pci_slot *slot;
dev = pci_alloc_dev(bus);
if (!dev)
@@ -145,10 +144,7 @@
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);
diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index c928bc6..3a0e1a9 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -249,7 +249,6 @@
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 @@
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 =
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index cefd636..2a9ce16 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1133,7 +1133,6 @@
{
u32 class;
u8 hdr_type;
- struct pci_slot *slot;
int pos = 0;
struct pci_bus_region region;
struct resource *res;
@@ -1149,10 +1148,7 @@
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;
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index 4bd3fce..429d34c 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -194,6 +194,17 @@
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;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aaee493..b3ba7fe 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -798,6 +798,11 @@
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);