[PATCH 11/13] USB: Phidget: fix race in device_create

From: Greg Kroah-Hartman
Date: Tue May 20 2008 - 18:41:51 EST


There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata(). It fixes all 3 phidget drivers, which all have
the same problem.

Cc: Kay Sievers <kay.sievers@xxxxxxxx>
Cc: Sean Young <sean@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/misc/phidgetkit.c | 6 +++---
drivers/usb/misc/phidgetmotorcontrol.c | 7 +++----
drivers/usb/misc/phidgetservo.c | 6 +++---
3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/misc/phidgetkit.c b/drivers/usb/misc/phidgetkit.c
index 24230c6..4cfa25b 100644
--- a/drivers/usb/misc/phidgetkit.c
+++ b/drivers/usb/misc/phidgetkit.c
@@ -595,14 +595,14 @@ static int interfacekit_probe(struct usb_interface *intf, const struct usb_devic
} while(value);
kit->dev_no = bit;

- kit->dev = device_create(phidget_class, &kit->udev->dev, 0,
- "interfacekit%d", kit->dev_no);
+ kit->dev = device_create_drvdata(phidget_class, &kit->udev->dev,
+ MKDEV(0, 0), kit,
+ "interfacekit%d", kit->dev_no);
if (IS_ERR(kit->dev)) {
rc = PTR_ERR(kit->dev);
kit->dev = NULL;
goto out;
}
- dev_set_drvdata(kit->dev, kit);

if (usb_submit_urb(kit->irq, GFP_KERNEL)) {
rc = -EIO;
diff --git a/drivers/usb/misc/phidgetmotorcontrol.c b/drivers/usb/misc/phidgetmotorcontrol.c
index f0113c1..9b4696f 100644
--- a/drivers/usb/misc/phidgetmotorcontrol.c
+++ b/drivers/usb/misc/phidgetmotorcontrol.c
@@ -365,16 +365,15 @@ static int motorcontrol_probe(struct usb_interface *intf, const struct usb_devic
} while(value);
mc->dev_no = bit;

- mc->dev = device_create(phidget_class, &mc->udev->dev, 0,
- "motorcontrol%d", mc->dev_no);
+ mc->dev = device_create_drvdata(phidget_class, &mc->udev->dev,
+ MKDEV(0, 0), mc,
+ "motorcontrol%d", mc->dev_no);
if (IS_ERR(mc->dev)) {
rc = PTR_ERR(mc->dev);
mc->dev = NULL;
goto out;
}

- dev_set_drvdata(mc->dev, mc);
-
if (usb_submit_urb(mc->irq, GFP_KERNEL)) {
rc = -EIO;
goto out;
diff --git a/drivers/usb/misc/phidgetservo.c b/drivers/usb/misc/phidgetservo.c
index 7d590c0..1ca7ddb 100644
--- a/drivers/usb/misc/phidgetservo.c
+++ b/drivers/usb/misc/phidgetservo.c
@@ -275,14 +275,14 @@ servo_probe(struct usb_interface *interface, const struct usb_device_id *id)
} while (value);
dev->dev_no = bit;

- dev->dev = device_create(phidget_class, &dev->udev->dev, 0,
- "servo%d", dev->dev_no);
+ dev->dev = device_create_drvdata(phidget_class, &dev->udev->dev,
+ MKDEV(0, 0), dev,
+ "servo%d", dev->dev_no);
if (IS_ERR(dev->dev)) {
rc = PTR_ERR(dev->dev);
dev->dev = NULL;
goto out;
}
- dev_set_drvdata(dev->dev, dev);

servo_count = dev->type & SERVO_COUNT_QUAD ? 4 : 1;

--
1.5.5.1

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