drivers/base: check errors

Add lots of return-value checking.

<pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 104 insertions, 50 deletions

diff --git a/drivers/base/base.h b/drivers/base/base.h
index c3b8dc98b8a7..d26644a59537 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -16,7 +16,7 @@ extern int cpu_dev_init(void);
 extern int attribute_container_init(void);
 
 extern int bus_add_device(struct device * dev);
-extern void bus_attach_device(struct device * dev);
+extern int bus_attach_device(struct device * dev);
 extern void bus_remove_device(struct device * dev);
 extern struct bus_type *get_bus(struct bus_type * bus);
 extern void put_bus(struct bus_type * bus);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 4d22a1d10a1c..aa685a20b649 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -371,12 +371,20 @@ int bus_add_device(struct device * dev)
         if (bus) {
                 pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
                 error = device_add_attrs(bus, dev);
-                if (!error) {
-                        sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
-                        sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem");
-                        sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
-                }
+                if (error)
+                        goto out;
+                error = sysfs_create_link(&bus->devices.kobj,
+                                                &dev->kobj, dev->bus_id);
+                if (error)
+                        goto out;
+                error = sysfs_create_link(&dev->kobj,
+                                &dev->bus->subsys.kset.kobj, "subsystem");
+                if (error)
+                        goto out;
+                error = sysfs_create_link(&dev->kobj,
+                                &dev->bus->subsys.kset.kobj, "bus");
         }
+out:
         return error;
 }
 
@@ -386,14 +394,19 @@ int bus_add_device(struct device * dev)
  *
  *      - Try to attach to driver.
  */
-void bus_attach_device(struct device * dev)
+int bus_attach_device(struct device * dev)
 {
-        struct bus_type * bus = dev->bus;
+        struct bus_type *bus = dev->bus;
+        int ret = 0;
 
         if (bus) {
-                device_attach(dev);
-                klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+                ret = device_attach(dev);
+                if (ret >= 0) {
+                        klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+                        ret = 0;
+                }
         }
+        return ret;
 }
 
 /**
@@ -455,10 +468,17 @@ static void driver_remove_attrs(struct bus_type * bus, struct device_driver * dr
  * Thanks to drivers making their tables __devinit, we can't allow manual
  * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
  */
-static void add_bind_files(struct device_driver *drv)
+static int __must_check add_bind_files(struct device_driver *drv)
 {
-        driver_create_file(drv, &driver_attr_unbind);
-        driver_create_file(drv, &driver_attr_bind);
+        int ret;
+
+        ret = driver_create_file(drv, &driver_attr_unbind);
+        if (ret == 0) {
+                ret = driver_create_file(drv, &driver_attr_bind);
+                if (ret)
+                        driver_remove_file(drv, &driver_attr_unbind);
+        }
+        return ret;
 }
 
 static void remove_bind_files(struct device_driver *drv)
@@ -476,7 +496,7 @@ static inline void remove_bind_files(struct device_driver *drv) {}
  *      @drv:   driver.
  *
  */
-int bus_add_driver(struct device_driver * drv)
+int bus_add_driver(struct device_driver *drv)
 {
         struct bus_type * bus = get_bus(drv->bus);
         int error = 0;
@@ -484,27 +504,39 @@ int bus_add_driver(struct device_driver * drv)
         if (bus) {
                 pr_debug("bus %s: add driver %s\n", bus->name, drv->name);
                 error = kobject_set_name(&drv->kobj, "%s", drv->name);
-                if (error) {
-                        put_bus(bus);
-                        return error;
-                }
+                if (error)
+                        goto out_put_bus;
                 drv->kobj.kset = &bus->drivers;
-                if ((error = kobject_register(&drv->kobj))) {
-                        put_bus(bus);
-                        return error;
-                }
+                if ((error = kobject_register(&drv->kobj)))
+                        goto out_put_bus;
 
-                driver_attach(drv);
+                error = driver_attach(drv);
+                if (error)
+                        goto out_unregister;
                 klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
                 module_add_driver(drv->owner, drv);
 
-                driver_add_attrs(bus, drv);
-                add_bind_files(drv);
+                error = driver_add_attrs(bus, drv);
+                if (error) {
+                        /* How the hell do we get out of this pickle? Give up */
+                        printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
+                                __FUNCTION__, drv->name);
+                }
+                error = add_bind_files(drv);
+                if (error) {
+                        /* Ditto */
+                        printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
+                                __FUNCTION__, drv->name);
+                }
         }
         return error;
+out_unregister:
+        kobject_unregister(&drv->kobj);
+out_put_bus:
+        put_bus(bus);
+        return error;
 }
 
-
 /**
  *      bus_remove_driver - delete driver from bus's knowledge.
  *      @drv:   driver.
@@ -530,16 +562,21 @@ void bus_remove_driver(struct device_driver * drv)
 
 
 /* Helper for bus_rescan_devices's iter */
-static int bus_rescan_devices_helper(struct device *dev, void *data)
+static int __must_check bus_rescan_devices_helper(struct device *dev,
+                                                void *data)
 {
+        int ret = 0;
+
         if (!dev->driver) {
                 if (dev->parent)        /* Needed for USB */
                         down(&dev->parent->sem);
-                device_attach(dev);
+                ret = device_attach(dev);
                 if (dev->parent)
                         up(&dev->parent->sem);
+                if (ret > 0)
+                        ret = 0;
         }
-        return 0;
+        return ret < 0 ? ret : 0;
 }
 
 /**
@@ -550,9 +587,9 @@ static int bus_rescan_devices_helper(struct device *dev, void *data)
  * attached and rescan it against existing drivers to see if it matches
  * any by calling device_attach() for the unbound devices.
  */
-void bus_rescan_devices(struct bus_type * bus)
+int bus_rescan_devices(struct bus_type * bus)
 {
-        bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
+        return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
 }
 
 /**
@@ -564,7 +601,7 @@ void bus_rescan_devices(struct bus_type * bus)
  * to use if probing criteria changed during a devices lifetime and
  * driver attachment should change accordingly.
  */
-void device_reprobe(struct device *dev)
+int device_reprobe(struct device *dev)
 {
         if (dev->driver) {
                 if (dev->parent)        /* Needed for USB */
@@ -573,14 +610,14 @@ void device_reprobe(struct device *dev)
                 if (dev->parent)
                         up(&dev->parent->sem);
         }
-
-        bus_rescan_devices_helper(dev, NULL);
+        return bus_rescan_devices_helper(dev, NULL);
 }
 EXPORT_SYMBOL_GPL(device_reprobe);
 
-struct bus_type * get_bus(struct bus_type * bus)
+struct bus_type *get_bus(struct bus_type *bus)
 {
-        return bus ? container_of(subsys_get(&bus->subsys), struct bus_type, subsys) : NULL;
+        return bus ? container_of(subsys_get(&bus->subsys),
+                                struct bus_type, subsys) : NULL;
 }
 
 void put_bus(struct bus_type * bus)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 889c71111239..9f6f11ca0ab6 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -38,17 +38,29 @@
  *
  *      This function must be called with @dev->sem held.
  */
-void device_bind_driver(struct device * dev)
+int device_bind_driver(struct device *dev)
 {
-        if (klist_node_attached(&dev->knode_driver))
-                return;
+        int ret;
+
+        if (klist_node_attached(&dev->knode_driver)) {
+                printk(KERN_WARNING "%s: device %s already bound\n",
+                        __FUNCTION__, kobject_name(&dev->kobj));
+                return 0;
+        }
 
         pr_debug("bound device '%s' to driver '%s'\n",
                  dev->bus_id, dev->driver->name);
         klist_add_tail(&dev->knode_driver, &dev->driver->klist_devices);
-        sysfs_create_link(&dev->driver->kobj, &dev->kobj,
+        ret = sysfs_create_link(&dev->driver->kobj, &dev->kobj,
                           kobject_name(&dev->kobj));
-        sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
+        if (ret == 0) {
+                ret = sysfs_create_link(&dev->kobj, &dev->driver->kobj,
+                                        "driver");
+                if (ret)
+                        sysfs_remove_link(&dev->driver->kobj,
+                                        kobject_name(&dev->kobj));
+        }
+        return ret;
 }
 
 /**
@@ -91,7 +103,11 @@ int driver_probe_device(struct device_driver * drv, struct device * dev)
                         goto ProbeFailed;
                 }
         }
-        device_bind_driver(dev);
+        if (device_bind_driver(dev)) {
+                printk(KERN_ERR "%s: device_bind_driver(%s) failed\n",
+                        __FUNCTION__, dev->bus_id);
+                /* How does undo a ->probe?  We're screwed. */
+        }
         ret = 1;
         pr_debug("%s: Bound Device %s to Driver %s\n",
                  drv->bus->name, dev->bus_id, drv->name);
@@ -139,8 +155,9 @@ int device_attach(struct device * dev)
 
         down(&dev->sem);
         if (dev->driver) {
-                device_bind_driver(dev);
-                ret = 1;
+                ret = device_bind_driver(dev);
+                if (ret == 0)
+                        ret = 1;
         } else
                 ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
         up(&dev->sem);
@@ -182,9 +199,9 @@ static int __driver_attach(struct device * dev, void * data)
  *      returns 0 and the @dev->driver is set, we've found a
  *      compatible pair.
  */
-void driver_attach(struct device_driver * drv)
+int driver_attach(struct device_driver * drv)
 {
-        bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
+        return bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
 }
 
 /**
diff --git a/include/linux/device.h b/include/linux/device.h
index ad4db72f5733..b3da9a870cfc 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -62,7 +62,7 @@ struct bus_type {
 extern int __must_check bus_register(struct bus_type * bus);
 extern void bus_unregister(struct bus_type * bus);
 
-extern void bus_rescan_devices(struct bus_type * bus);
+extern int __must_check bus_rescan_devices(struct bus_type * bus);
 
 /* iterator helpers for buses */
 
@@ -397,11 +397,11 @@ extern int device_rename(struct device *dev, char *new_name);
  * Manual binding of a device to driver. See drivers/base/bus.c
  * for information on use.
  */
-extern void device_bind_driver(struct device * dev);
+extern int __must_check device_bind_driver(struct device *dev);
 extern void device_release_driver(struct device * dev);
 extern int  __must_check device_attach(struct device * dev);
-extern void driver_attach(struct device_driver * drv);
-extern void device_reprobe(struct device *dev);
+extern int __must_check driver_attach(struct device_driver *drv);
+extern int __must_check device_reprobe(struct device *dev);
 
 /*
  * Easy functions for dynamically creating devices on the fly