[patch] drivers: Fix bogus 0 error return in device_add()

[Thomas Gleixner <tglx@linutronix.de>]

[-- Attachment #1: drivers-base-fix-error-path.patch --]
[-- Type: text/plain, Size: 1168 bytes --]

If device_add() is called with a device which does not have dev->p set
up, then device_private_init() is called. If that succeeds, then the
error variable is set to 0. Now if the dev_name(dev) check further
down fails, then device_add() correctly terminates, but returns 0.
That of course lets the driver progress. If later another driver uses
this half set up device as parent then device_add() of the child
device explodes and renders sysfs completely unusable.

Set the error to -EINVAL if dev_name() check fails.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
---
 drivers/base/core.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6-tip/drivers/base/core.c
===================================================================
--- linux-2.6-tip.orig/drivers/base/core.c
+++ linux-2.6-tip/drivers/base/core.c
@@ -898,8 +898,10 @@ int device_add(struct device *dev)
 		dev->init_name = NULL;
 	}
 
-	if (!dev_name(dev))
+	if (!dev_name(dev)) {
+		error = -EINVAL;
 		goto name_error;
+	}
 
 	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);