From c560d105a197464603247bf55962fc7f23c8cb62 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 26 May 2010 23:27:07 +0200 Subject: [PATCH] [S390] ccwgroup: add locking around drvdata access Several processes may concurrently try to create a group device from the same ccw_device(s). Add locking arround the drvdata access to prevent race conditions. Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/ccwgroup.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c index 5f97ea2ee6b1..97b25d68e3e7 100644 --- a/drivers/s390/cio/ccwgroup.c +++ b/drivers/s390/cio/ccwgroup.c @@ -123,8 +123,10 @@ ccwgroup_release (struct device *dev) for (i = 0; i < gdev->count; i++) { if (gdev->cdev[i]) { + spin_lock_irq(gdev->cdev[i]->ccwlock); if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev) dev_set_drvdata(&gdev->cdev[i]->dev, NULL); + spin_unlock_irq(gdev->cdev[i]->ccwlock); put_device(&gdev->cdev[i]->dev); } } @@ -262,11 +264,14 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id, goto error; } /* Don't allow a device to belong to more than one group. */ + spin_lock_irq(gdev->cdev[i]->ccwlock); if (dev_get_drvdata(&gdev->cdev[i]->dev)) { + spin_unlock_irq(gdev->cdev[i]->ccwlock); rc = -EINVAL; goto error; } dev_set_drvdata(&gdev->cdev[i]->dev, gdev); + spin_unlock_irq(gdev->cdev[i]->ccwlock); } /* Check for sufficient number of bus ids. */ if (i < num_devices && !curr_buf) { @@ -303,8 +308,10 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id, error: for (i = 0; i < num_devices; i++) if (gdev->cdev[i]) { + spin_lock_irq(gdev->cdev[i]->ccwlock); if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev) dev_set_drvdata(&gdev->cdev[i]->dev, NULL); + spin_unlock_irq(gdev->cdev[i]->ccwlock); put_device(&gdev->cdev[i]->dev); gdev->cdev[i] = NULL; } -- 2.20.1