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authorSergey Klyaus <Sergey.Klyaus@tune-it.ru>2014-10-08 11:31:54 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-07 11:14:57 -0800
commit0cd75047de7f54d6fb4aba0ec5818f8194815a5a (patch)
tree32fd93ff2934eef026907e747ee6fe6456785687 /drivers/base
parent4ef67a8c95f32ed0c8c6ed5fe01d1dd16358350e (diff)
downloadop-kernel-dev-0cd75047de7f54d6fb4aba0ec5818f8194815a5a.zip
op-kernel-dev-0cd75047de7f54d6fb4aba0ec5818f8194815a5a.tar.gz
driver core: fix race with userland in device_add()
bus_add_device() should be called before devtmpfs_create_node(), so when userland application opens device from devtmpfs, it wouldn't get ENODEV from kernel, because device_add() wasn't completed. Signed-off-by: Sergey Klyaus <Sergey.Klyaus@Tune-IT.Ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/core.c38
1 files changed, 18 insertions, 20 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 14d1629..00ec7ce 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1019,18 +1019,6 @@ int device_add(struct device *dev)
if (error)
goto attrError;
- if (MAJOR(dev->devt)) {
- error = device_create_file(dev, &dev_attr_dev);
- if (error)
- goto ueventattrError;
-
- error = device_create_sys_dev_entry(dev);
- if (error)
- goto devtattrError;
-
- devtmpfs_create_node(dev);
- }
-
error = device_add_class_symlinks(dev);
if (error)
goto SymlinkError;
@@ -1045,6 +1033,18 @@ int device_add(struct device *dev)
goto DPMError;
device_pm_add(dev);
+ if (MAJOR(dev->devt)) {
+ error = device_create_file(dev, &dev_attr_dev);
+ if (error)
+ goto DevAttrError;
+
+ error = device_create_sys_dev_entry(dev);
+ if (error)
+ goto SysEntryError;
+
+ devtmpfs_create_node(dev);
+ }
+
/* Notify clients of device addition. This call must come
* after dpm_sysfs_add() and before kobject_uevent().
*/
@@ -1074,6 +1074,12 @@ int device_add(struct device *dev)
done:
put_device(dev);
return error;
+ SysEntryError:
+ if (MAJOR(dev->devt))
+ device_remove_file(dev, &dev_attr_dev);
+ DevAttrError:
+ device_pm_remove(dev);
+ dpm_sysfs_remove(dev);
DPMError:
bus_remove_device(dev);
BusError:
@@ -1081,14 +1087,6 @@ done:
AttrsError:
device_remove_class_symlinks(dev);
SymlinkError:
- if (MAJOR(dev->devt))
- devtmpfs_delete_node(dev);
- if (MAJOR(dev->devt))
- device_remove_sys_dev_entry(dev);
- devtattrError:
- if (MAJOR(dev->devt))
- device_remove_file(dev, &dev_attr_dev);
- ueventattrError:
device_remove_file(dev, &dev_attr_uevent);
attrError:
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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