diff options
| -rw-r--r-- | drivers/base/bus.c | 20 | ||||
| -rw-r--r-- | drivers/base/core.c | 14 | ||||
| -rw-r--r-- | drivers/base/cpu.c | 10 | ||||
| -rw-r--r-- | include/linux/device/bus.h | 1 |
4 files changed, 39 insertions, 6 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 301b9c6ece86..def1e009ad9d 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -1334,6 +1334,26 @@ bool bus_is_registered(const struct bus_type *bus) return is_initialized; } +/** + * bus_get_dev_root - return a pointer to the "device root" of a bus + * @bus: bus to return the device root of. + * + * If a bus has a "device root" structure, return it, WITH THE REFERENCE + * COUNT INCREMENTED. + * + * Note, when finished with the device, a call to put_device() is required. + * + * If the device root is not present (or bus is not a valid pointer), NULL + * will be returned. + */ +struct device *bus_get_dev_root(const struct bus_type *bus) +{ + if (bus) + return get_device(bus->dev_root); + return NULL; +} +EXPORT_SYMBOL_GPL(bus_get_dev_root); + int __init buses_init(void) { bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); diff --git a/drivers/base/core.c b/drivers/base/core.c index 2712a1a1e959..f9297c68214a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -3173,8 +3173,9 @@ static DEFINE_MUTEX(gdp_mutex); static struct kobject *get_device_parent(struct device *dev, struct device *parent) { + struct kobject *kobj = NULL; + if (dev->class) { - struct kobject *kobj = NULL; struct kobject *parent_kobj; struct kobject *k; @@ -3222,8 +3223,15 @@ static struct kobject *get_device_parent(struct device *dev, } /* subsystems can specify a default root directory for their devices */ - if (!parent && dev->bus && dev->bus->dev_root) - return &dev->bus->dev_root->kobj; + if (!parent && dev->bus) { + struct device *dev_root = bus_get_dev_root(dev->bus); + + if (dev_root) { + kobj = &dev_root->kobj; + put_device(dev_root); + return kobj; + } + } if (parent) return &parent->kobj; diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 441eb5bdec7d..8bb623039bb2 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -610,9 +610,13 @@ static const struct attribute_group cpu_root_vulnerabilities_group = { static void __init cpu_register_vulnerabilities(void) { - if (sysfs_create_group(&cpu_subsys.dev_root->kobj, - &cpu_root_vulnerabilities_group)) - pr_err("Unable to register CPU vulnerabilities\n"); + struct device *dev = bus_get_dev_root(&cpu_subsys); + + if (dev) { + if (sysfs_create_group(&dev->kobj, &cpu_root_vulnerabilities_group)) + pr_err("Unable to register CPU vulnerabilities\n"); + put_device(dev); + } } #else diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index 31be18608f83..6ce32ef4b8fd 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -282,5 +282,6 @@ enum bus_notifier_event { }; extern struct kset *bus_get_kset(const struct bus_type *bus); +struct device *bus_get_dev_root(const struct bus_type *bus); #endif |