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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-03-18 22:40:04 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-03-18 22:40:04 +0100
commit71150d226564686ef32d15d29edfd18346f6e929 (patch)
treec591756e18763e1a935b52b7464e5d7b4a77d6ac
parent38f6b38dbb0896511c509fbb6ceabbedbee8e87d (diff)
downloadlinux-71150d226564686ef32d15d29edfd18346f6e929.tar.bz2
PNP: Avoid leaving unregistered device objects in lists
pnp_register_protocol() and __pnp_add_device() both have a problem that if device_register() fails, the objects they create will be left in the lists they have been put one beforehand. Unfortunately, that is not handled by the callers of those routines either, so in case of a device registration errors the PNP bus type's data structures will end up in an inconsistent state. Make pnp_register_protocol() and __pnp_add_device() remove the objects from the lists if device registration fails. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--drivers/pnp/core.c53
1 files changed, 40 insertions, 13 deletions
diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c
index ef2f59c4e57c..b54620e53830 100644
--- a/drivers/pnp/core.c
+++ b/drivers/pnp/core.c
@@ -42,6 +42,13 @@ void *pnp_alloc(long size)
return result;
}
+static void pnp_remove_protocol(struct pnp_protocol *protocol)
+{
+ mutex_lock(&pnp_lock);
+ list_del(&protocol->protocol_list);
+ mutex_unlock(&pnp_lock);
+}
+
/**
* pnp_protocol_register - adds a pnp protocol to the pnp layer
* @protocol: pointer to the corresponding pnp_protocol structure
@@ -50,12 +57,13 @@ void *pnp_alloc(long size)
*/
int pnp_register_protocol(struct pnp_protocol *protocol)
{
- int nodenum;
struct list_head *pos;
+ int nodenum, ret;
INIT_LIST_HEAD(&protocol->devices);
INIT_LIST_HEAD(&protocol->cards);
nodenum = 0;
+
mutex_lock(&pnp_lock);
/* assign the lowest unused number */
@@ -67,12 +75,18 @@ int pnp_register_protocol(struct pnp_protocol *protocol)
}
}
+ protocol->number = nodenum;
+ dev_set_name(&protocol->dev, "pnp%d", nodenum);
+
list_add_tail(&protocol->protocol_list, &pnp_protocols);
+
mutex_unlock(&pnp_lock);
- protocol->number = nodenum;
- dev_set_name(&protocol->dev, "pnp%d", nodenum);
- return device_register(&protocol->dev);
+ ret = device_register(&protocol->dev);
+ if (ret)
+ pnp_remove_protocol(protocol);
+
+ return ret;
}
/**
@@ -81,9 +95,7 @@ int pnp_register_protocol(struct pnp_protocol *protocol)
*/
void pnp_unregister_protocol(struct pnp_protocol *protocol)
{
- mutex_lock(&pnp_lock);
- list_del(&protocol->protocol_list);
- mutex_unlock(&pnp_lock);
+ pnp_remove_protocol(protocol);
device_unregister(&protocol->dev);
}
@@ -158,18 +170,36 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id,
return dev;
}
+static void pnp_delist_device(struct pnp_dev *dev)
+{
+ mutex_lock(&pnp_lock);
+ list_del(&dev->global_list);
+ list_del(&dev->protocol_list);
+ mutex_unlock(&pnp_lock);
+}
+
int __pnp_add_device(struct pnp_dev *dev)
{
+ int ret;
+
pnp_fixup_device(dev);
dev->status = PNP_READY;
+
mutex_lock(&pnp_lock);
+
list_add_tail(&dev->global_list, &pnp_global);
list_add_tail(&dev->protocol_list, &dev->protocol->devices);
+
mutex_unlock(&pnp_lock);
- if (dev->protocol->can_wakeup)
+
+ ret = device_register(&dev->dev);
+ if (ret)
+ pnp_delist_device(dev);
+ else if (dev->protocol->can_wakeup)
device_set_wakeup_capable(&dev->dev,
dev->protocol->can_wakeup(dev));
- return device_register(&dev->dev);
+
+ return ret;
}
/*
@@ -204,10 +234,7 @@ int pnp_add_device(struct pnp_dev *dev)
void __pnp_remove_device(struct pnp_dev *dev)
{
- mutex_lock(&pnp_lock);
- list_del(&dev->global_list);
- list_del(&dev->protocol_list);
- mutex_unlock(&pnp_lock);
+ pnp_delist_device(dev);
device_unregister(&dev->dev);
}