Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here are all of the driver core and related patches for 4.19-rc1.

  Nothing huge here, just a number of small cleanups and the ability to
  now stop the deferred probing after init happens.

  All of these have been in linux-next for a while with only a merge
  issue reported"

* tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
  base: core: Remove WARN_ON from link dependencies check
  drivers/base: stop new probing during shutdown
  drivers: core: Remove glue dirs from sysfs earlier
  driver core: remove unnecessary function extern declare
  sysfs.h: fix non-kernel-doc comment
  PM / Domains: Stop deferring probe at the end of initcall
  iommu: Remove IOMMU_OF_DECLARE
  iommu: Stop deferring probe at end of initcalls
  pinctrl: Support stopping deferred probe after initcalls
  dt-bindings: pinctrl: add a 'pinctrl-use-default' property
  driver core: allow stopping deferred probe after init
  driver core: add a debugfs entry to show deferred devices
  sysfs: Fix internal_create_group() for named group updates
  base: fix order of OF initialization
  linux/device.h: fix kernel-doc notation warning
  Documentation: update firmware loader fallback reference
  kobject: Replace strncpy with memcpy
  drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number
  kernfs: Replace strncpy with memcpy
  device: Add #define dev_fmt similar to #define pr_fmt
  ...

1 files changed, 22 insertions, 8 deletions

diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index c7a716c4acc9..1eb2d6307663 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -124,13 +124,22 @@ static int internal_create_group(struct kobject *kobj, int update,
 	}
 	kobject_get_ownership(kobj, &uid, &gid);
 	if (grp->name) {
-		kn = kernfs_create_dir_ns(kobj->sd, grp->name,
-					  S_IRWXU | S_IRUGO | S_IXUGO,
-					  uid, gid, kobj, NULL);
-		if (IS_ERR(kn)) {
-			if (PTR_ERR(kn) == -EEXIST)
-				sysfs_warn_dup(kobj->sd, grp->name);
-			return PTR_ERR(kn);
+		if (update) {
+			kn = kernfs_find_and_get(kobj->sd, grp->name);
+			if (!kn) {
+				pr_warn("Can't update unknown attr grp name: %s/%s\n",
+					kobj->name, grp->name);
+				return -EINVAL;
+			}
+		} else {
+			kn = kernfs_create_dir_ns(kobj->sd, grp->name,
+						  S_IRWXU | S_IRUGO | S_IXUGO,
+						  uid, gid, kobj, NULL);
+			if (IS_ERR(kn)) {
+				if (PTR_ERR(kn) == -EEXIST)
+					sysfs_warn_dup(kobj->sd, grp->name);
+				return PTR_ERR(kn);
+			}
 		}
 	} else
 		kn = kobj->sd;
@@ -141,6 +150,10 @@ static int internal_create_group(struct kobject *kobj, int update,
 			kernfs_remove(kn);
 	}
 	kernfs_put(kn);
+
+	if (grp->name && update)
+		kernfs_put(kn);
+
 	return error;
 }
 
@@ -205,7 +218,8 @@ EXPORT_SYMBOL_GPL(sysfs_create_groups);
  * of the attribute files being created already exist.  Furthermore,
  * if the visibility of the files has changed through the is_visible()
  * callback, it will update the permissions and add or remove the
- * relevant files.
+ * relevant files. Changing a group's name (subdirectory name under
+ * kobj's directory in sysfs) is not allowed.
  *
  * The primary use for this function is to call it after making a change
  * that affects group visibility.