diff options
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r-- | drivers/base/core.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 6bee6af8d8e1..f33d768164ac 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -56,7 +56,14 @@ static inline int device_is_not_partition(struct device *dev) */ const char *dev_driver_string(const struct device *dev) { - return dev->driver ? dev->driver->name : + struct device_driver *drv; + + /* dev->driver can change to NULL underneath us because of unbinding, + * so be careful about accessing it. dev->bus and dev->class should + * never change once they are set, so they don't need special care. + */ + drv = ACCESS_ONCE(dev->driver); + return drv ? drv->name : (dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "")); } @@ -596,6 +603,7 @@ static struct kobject *get_device_parent(struct device *dev, int retval; if (dev->class) { + static DEFINE_MUTEX(gdp_mutex); struct kobject *kobj = NULL; struct kobject *parent_kobj; struct kobject *k; @@ -612,6 +620,8 @@ static struct kobject *get_device_parent(struct device *dev, else parent_kobj = &parent->kobj; + mutex_lock(&gdp_mutex); + /* find our class-directory at the parent and reference it */ spin_lock(&dev->class->p->class_dirs.list_lock); list_for_each_entry(k, &dev->class->p->class_dirs.list, entry) @@ -620,20 +630,26 @@ static struct kobject *get_device_parent(struct device *dev, break; } spin_unlock(&dev->class->p->class_dirs.list_lock); - if (kobj) + if (kobj) { + mutex_unlock(&gdp_mutex); return kobj; + } /* or create a new class-directory at the parent device */ k = kobject_create(); - if (!k) + if (!k) { + mutex_unlock(&gdp_mutex); return NULL; + } k->kset = &dev->class->p->class_dirs; retval = kobject_add(k, parent_kobj, "%s", dev->class->name); if (retval < 0) { + mutex_unlock(&gdp_mutex); kobject_put(k); return NULL; } /* do not emit an uevent for this simple "glue" directory */ + mutex_unlock(&gdp_mutex); return k; } |