Messages in this thread Patch in this message | | | From | Alex Chiang <> | Subject | [PATCH v4 02/15] PCI Hotplug: serialize pci_hp_register/deregister | Date | Fri, 03 Oct 2008 17:17:37 -0600 |
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Add explicit locking to pci_hp_register/deregister. For a given pci_slot, we want to make sure that the pci_slot->hotplug pointer isn't being changed from underneath us.
Cc: jbarnes@virtuousgeek.org Cc: kristen.c.accardi@intel.com Cc: matthew@wil.cx Cc: kaneshige.kenji@jp.fujitsu.com Signed-off-by: Alex Chiang <achiang@hp.com> ---
drivers/pci/hotplug/pci_hotplug_core.c | 7 +++++++ drivers/pci/slot.c | 4 ++-- 2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c index 0e7a511..e00266b 100644 --- a/drivers/pci/hotplug/pci_hotplug_core.c +++ b/drivers/pci/hotplug/pci_hotplug_core.c @@ -37,6 +37,7 @@ #include <linux/init.h> #include <linux/mount.h> #include <linux/namei.h> +#include <linux/mutex.h> #include <linux/pci.h> #include <linux/pci_hotplug.h> #include <asm/uaccess.h> @@ -554,6 +555,7 @@ out: * * Returns 0 if successful, anything else for an error. */ +static DEFINE_MUTEX(pci_hp_mutex); int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr, const char *name) { @@ -583,7 +585,9 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr, if (IS_ERR(pci_slot)) return PTR_ERR(pci_slot); + mutex_lock(&pci_hp_mutex); if (pci_slot->hotplug) { + mutex_unlock(&pci_hp_mutex); dbg("%s: already claimed\n", __func__); pci_destroy_slot(pci_slot); return -EBUSY; @@ -591,6 +595,7 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr, slot->pci_slot = pci_slot; pci_slot->hotplug = slot; + mutex_unlock(&pci_hp_mutex); /* * Allow pcihp drivers to override the ACPI_PCI_SLOT name. @@ -635,6 +640,7 @@ int pci_hp_deregister(struct hotplug_slot *hotplug) if (temp != hotplug) return -ENODEV; + mutex_lock(&pci_hp_mutex); spin_lock(&pci_hotplug_slot_list_lock); list_del(&hotplug->slot_list); spin_unlock(&pci_hotplug_slot_list_lock); @@ -645,6 +651,7 @@ int pci_hp_deregister(struct hotplug_slot *hotplug) hotplug->release(hotplug); slot->hotplug = NULL; + mutex_unlock(&pci_hp_mutex); pci_destroy_slot(slot); return 0; diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index 0c6db03..1fffb27 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -164,10 +164,10 @@ placeholder: pr_debug("%s: created pci_slot on %04x:%02x:%02x\n", __func__, pci_domain_nr(parent), parent->number, slot_nr); - out: +out: up_write(&pci_bus_sem); return slot; - err: +err: kfree(slot); slot = ERR_PTR(err); goto out;
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