[ Upstream commit 079ad2fb4bf9eba8a0aaab014b49705cd7f07c66 ]

If kobject_del() is invoked by kobject_cleanup() to delete the
target kobject, it may cause its parent kobject to be freed
before invoking the target kobject's ->release() method, which
effectively means freeing the parent before dealing with the
child entirely.

That is confusing at best and it may also lead to functional
issues if the callers of kobject_cleanup() are not careful enough
about the order in which these calls are made, so avoid the
problem by making kobject_cleanup() drop the last reference to
the target kobject's parent at the end, after invoking the target
kobject's ->release() method.

[ rjw: Rewrite the subject and changelog, make kobject_cleanup()
  drop the parent reference only when __kobject_del() has been
  called. ]

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: 7589238a8cf3 ("Revert "software node: Simplify software_node_release() function"")
Suggested-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/1908555.IiAGLGrh1Z@kreacher
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

the kobj refcount increased by kobject_get should be released before
error return, otherwise lead to a memory leak.

Signed-off-by: Lin Yi <teroincn@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 1fd7c3b438a2 ("kobject: Improve doc clarity kobject_init_and_add()")
tried to provide more clarity, but the reference to kobject_del() was
incorrect.  Fix that up by removing that line, and hopefully be more explicit
as to exactly what needs to happen here once you register a kobject with the
kobject core.

Acked-by: Tobin C. Harding <tobin@kernel.org>
Fixes: 1fd7c3b438a2 ("kobject: Improve doc clarity kobject_init_and_add()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel-doc comments have a prescribed format.  This includes parenthesis
on the function name.  To be _particularly_ correct we should also
capitalise the brief description and terminate it with a period.

In preparation for adding/updating kernel-doc function comments clean up
the ones currently present.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently the docstring for kobject_get_path() mentions 'kset'.  The
kset is not used in the function callchain starting from this function.

Remove docstring reference to kset from the function kobject_get_path().

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The kobj pointer is being null-checked so potentially it could be null,
however, the ktype declaration before the null check is dereferencing kobj
hence we have a potential null pointer deference. Fix this by moving the
assignment of ktype after kobj has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Function kobject_init_and_add() is currently misused in a number of
places in the kernel.  On error return kobject_put() must be called but
is at times not.

Make the function documentation more explicit about calling
kobject_put() in the error path.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There is currently some confusion on how to wind back
kobject_init_and_add() during the error paths in code that uses this
function.

Add documentation to kobject_add() and kobject_del() to help clarify the
usage.

Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kobj_type currently uses a list of individual attributes to store
default attributes. Attribute groups are more flexible than a list of
attributes because groups provide support for attribute visibility. So,
add support for default attribute groups to kobj_type.

In future patches, the existing uses of kobj_type’s attribute list will
be converted to attribute groups. When that is complete, kobj_type’s
attribute list, “default_attrs”, will be removed.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kset_get_ownership() is only used in lib/kobject.c, so make it 'static'.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>