Commit graph

139 commits

Author SHA1 Message Date
Greg Kroah-Hartman
ddaf098ea7 driver core: class: properly reference count class_dev_iter()
When class_dev_iter is initialized, the reference count for the subsys
private structure is incremented, but never decremented, causing a
memory leak over time.  To resolve this, save off a pointer to the
internal structure into the class_dev_iter structure and then when the
iterator is finished, drop the reference count.

Reported-and-tested-by: syzbot+e7afd76ad060fa0d2605@syzkaller.appspotmail.com
Fixes: 7b884b7f24 ("driver core: class.c: convert to only use class_to_subsys")
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Link: https://lore.kernel.org/r/2023051610-stove-condense-9a77@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-19 11:03:36 +01:00
Greg Kroah-Hartman
2243acd50a driver core: class: remove struct class_interface * from callbacks
The add_dev and remove_dev callbacks in struct class_interface currently
pass in a pointer back to the class_interface structure that is calling
them, but none of the callback implementations actually use this pointer
as it is pointless (the structure is known, the driver passed it in in
the first place if it is really needed again.)

So clean this up and just remove the pointer from the callbacks and fix
up all callback functions.

Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: John Stultz <jstultz@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Cc: Jakob Koschel <jakobkoschel@gmail.com>
Cc: Cai Xinchen <caixinchen1@huawei.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/2023040250-pushover-platter-509c@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-03 21:42:52 +02:00
Greg Kroah-Hartman
6b0d49be81 driver core: class: mark the struct class in struct class_interface constant
The struct class pointer in struct class_interface is never modified, so
mark it as const so that no one accidentally tries to modify it in the
future.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023040249-handball-gruffly-5da7@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-03 21:42:48 +02:00
Greg Kroah-Hartman
43a7206b09 driver core: class: make class_register() take a const *
Now that the class code is cleaned up to not modify the class pointer
registered with it, change class_register() to take a const * to allow
the structure to be placed into read-only memory.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023040248-customary-release-4aec@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-03 21:42:46 +02:00
Greg Kroah-Hartman
979207cac5 driver core: class: mark class_release() as taking a const *
The struct class callback, class_release(), is only called in 2 places,
the pcmcia cardservices code, and in the class driver core code.  Both
places it is safe to mark the structure as a const *, to allow us to
in the future mark all struct class usages as constant and move into
read-only memory.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023040248-outrage-obsolete-5a9a@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-03 21:42:43 +02:00
Greg Kroah-Hartman
f326ea63ec driver core: class: fix slab-use-after-free Read in class_register()
Syzbot found that we had forgotten to unregister the lock_class_key when
using it in commit dcfbb67e48 ("driver core: class: use lock_class_key
already present in struct subsys_private") so fix that up and correctly
release it when done.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reported-and-tested-by: <syzbot+41d665317c811d4d88aa@syzkaller.appspotmail.com>
Fixes: dcfbb67e48 ("driver core: class: use lock_class_key already present in struct subsys_private")
Link: https://lore.kernel.org/r/2023040126-blandness-duckling-bd55@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-01 12:20:54 +02:00
Greg Kroah-Hartman
e78195d529 driver core: class: remove dev_kobj from struct class
The dev_kobj field in struct class is now only written to, but never
read from, so it can be removed as it is useless.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-5-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-31 17:45:11 +02:00
Greg Kroah-Hartman
2df418cf4b driver core: class: remove subsystem private pointer from struct class
Now that the last users of the subsystem private pointer in struct class
are gone, the pointer can be removed, as no one is using it.  One step
closer to allowing struct class to be const and moved into read-only
memory.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-31 17:45:03 +02:00
Greg Kroah-Hartman
6f14c02220 driver core: create class_is_registered()
Some classes (i.e. gpio), want to know if they have been registered or
not, and poke around in the class's internal structures to try to figure
this out.  Because this is not really a good idea, provide a function
for classes to call to try to figure this out.

Note, this is racy as the state of the class could change at any moment
in time after the call is made, but as usually a class only wants to
know if it has been registered yet or not, it should be fairly safe to
use, and is just as safe as the previous "poke at the class internals"
check was.

Move the gpiolib code to use this function as proof that it works
properly.

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-gpio@vger.kernel.org
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-31 17:44:54 +02:00
Greg Kroah-Hartman
7d90e81a2d driver core: core: move to use class_to_subsys()
There are a number of places in core.c that need access to the private
subsystem structure of struct class, so move them to use
class_to_subsys() instead of accessing it directly.

This requires exporting class_to_subsys() out of class.c, but keeping it
local to the driver core.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-31 15:13:35 +02:00
Greg Kroah-Hartman
7b884b7f24 driver core: class.c: convert to only use class_to_subsys
Now that class_to_subsys() can be used to get access to the internal
class private pointer, convert the remaining few places in class.c that
were accessing the pointer directly to use class_to_subsys() instead.

By doing this, the need for class_get() and class_put() goes away as no
one actually tries to increment the class structures anymore, only the
internal dynamic one.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230325194234.46588-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 07:55:10 +02:00
Greg Kroah-Hartman
884f8ce42c driver core: class: implement class_get/put without the private pointer.
Much like what was done in commit 273afac615 ("driver core: bus:
implement bus_get/put() without the private pointer"), it is time to
move the driver core away from using the internal private pointer in
struct class in order to enable it to be always a constant and be placed
in read-only memory in the future.

First step in doing this is to create a helper function that turns a
'struct class' into 'struct subsys_private' called class_to_subsys().

class_to_subsys() walks the list of registered busses in the system and
finds the matching one based on the pointer to the class itself.  As
this is a short list, and this function is not on any fast path, it
should not be noticable.

Implement class_get() and class_put() using this new helper function.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230325194234.46588-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 07:55:07 +02:00
Greg Kroah-Hartman
75a2d4226b driver core: class: mark the struct class for sysfs callbacks as constant
struct class should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
class to be moved to read-only memory.

While we are touching all class sysfs callbacks also mark the attribute
as constant as it can not be modified.  The bonding code still uses this
structure so it can not be removed from the function callbacks.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steve French <sfrench@samba.org>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-cifs@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: netdev@vger.kernel.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-29 07:54:58 +02:00
Greg Kroah-Hartman
517d4927aa driver core: bus: constify class_unregister/destroy()
The class_unregister() and class_destroy() function should be taking a
const * to struct class, not just a *, so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230325084526.3622123-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-28 08:27:48 +02:00
Greg Kroah-Hartman
170848d406 driver core: class: fix documentation for class_create()
In commit dcfbb67e48 ("driver core: class: use lock_class_key already
present in struct subsys_private") we removed the key parameter to the
function class_create() but forgot to remove it from the kerneldoc,
which causes a build warning.  Fix that up by removing the key parameter
from the documentation as it is now gone.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: dcfbb67e48 ("driver core: class: use lock_class_key already present in struct subsys_private")
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230327081828.1087364-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-27 14:34:02 +02:00
Greg Kroah-Hartman
dcfbb67e48 driver core: class: use lock_class_key already present in struct subsys_private
In commit 37e98d9bed ("driver core: bus: move lock_class_key into
dynamic structure"), we moved the lock_class_key into the internal
structure shared by busses and classes, but only used it for buses.

Move the class code to use this structure as it is already present and
being allocated, instead of the statically allocated on-the-stack
variable that class_create() was using as part of a macro wrapper around
the core function call.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230324100132.1633647-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-24 15:34:18 +01:00
Greg Kroah-Hartman
80842a9290 driver core: class: make class_create/remove_file*() options const
The class_create_file*() and class_remove_file*() functions do not
modify the struct class at all, so mark them as const * to enforce that.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-8-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:41 +01:00
Greg Kroah-Hartman
cf41015ea8 driver core: class: make class_find_device*() options const
The class_find_device*() functions do not modify the struct class or the
struct device passed into it, so mark them as const * to enforce that.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:39 +01:00
Greg Kroah-Hartman
69df024ebb driver core: class: make class_for_each_device() options const
class_for_each_device() does not modify the struct class or the struct
device passed into it, so mark them as const * to enforce that.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-6-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:37 +01:00
Greg Kroah-Hartman
a2fd6e42e4 driver core: class: make class_dev_iter_init() options const
class_dev_iter_init() does not modify the struct class or the struct
device passed into it, so mark them as const * to enforce that.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-5-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:35 +01:00
Greg Kroah-Hartman
6e30a66433 driver core: class: remove struct module owner out of struct class
The module owner field for a struct class was never actually used, so
remove it as it is not doing anything at all.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:30 +01:00
Greg Kroah-Hartman
4a46ac9d64 driver core: class: specify the module owner in __class_register()
There's no need to manually have to set the module owner of a class, the
compiler should do it automatically for you, so add a module * to the
__class_register() function and allow it to set the module owner
automatically.

This will let us move the module pointer out of struct class eventually,
as it should not be embedded in there if we wish for it to be a
read-only structure eventually.

And, funny story, this module pointer isn't even being used for
anything, so while we will keep it around for now, it's not like it even
matters.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313181843.1207845-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:24 +01:00
Greg Kroah-Hartman
22fd6153c1 driver core: class: fix block class problem when removing CONFIG_SYSFS_DEPRECATED*
In removing the CONFIG_SYSFS_DEPRECATED and CONFIG_SYSFS_DEPRECATED_V2
config options, I messed up in the __class_register() function and got
the logic incorrect.  Fix this all up by just removing the special case
of a block device class logic in this function, as that is what is
intended.

In testing, this solves the boot problem on my systems, hopefully on
others as well.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 721da5cee9 ("driver core: remove CONFIG_SYSFS_DEPRECATED and CONFIG_SYSFS_DEPRECATED_V2")
Link: https://lore.kernel.org/r/20230307075102.3537-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-07 09:24:29 +01:00
Greg Kroah-Hartman
721da5cee9 driver core: remove CONFIG_SYSFS_DEPRECATED and CONFIG_SYSFS_DEPRECATED_V2
CONFIG_SYSFS_DEPRECATED was added in commit 88a22c985e
("CONFIG_SYSFS_DEPRECATED") in 2006 to allow systems with older versions
of some tools (i.e. Fedora 3's version of udev) to boot properly.  Four
years later, in 2010, the option was attempted to be removed as most of
userspace should have been fixed up properly by then, but some kernel
developers clung to those old systems and refused to update, so we added
CONFIG_SYSFS_DEPRECATED_V2 in commit e52eec13cd ("SYSFS: Allow boot
time switching between deprecated and modern sysfs layout") to allow
them to continue to boot properly, and we allowed a boot time parameter
to be used to switch back to the old format if needed.

Over time, the logic that was covered under these config options was
slowly removed from individual driver subsystems successfully, removed,
and the only thing that is now left in the kernel are some changes in
the block layer's representation in sysfs where real directories are
used instead of symlinks like normal.

Because the original changes were done to userspace tools in 2006, and
all distros that use those tools are long end-of-life, and older
non-udev-based systems do not care about the block layer's sysfs
representation, it is time to finally remove this old logic and the
config entries from the kernel.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: linux-block@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Acked-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20230223073326.2073220-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-06 07:46:23 +01:00
Greg Kroah-Hartman
779aeb73d9 driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
For some reason, the drivers/base/class.c file still had the "old style"
of exports, at the end of the file.  Move the exports to the proper
location, right after the function, to be correct.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230214144117.158956-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-14 15:46:56 +01:00
Thomas Weißschuh
c83d9ab42f driver core: make kobj_type structures constant
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20230204-kobj_type-driver-core-v1-1-b9f809419f2c@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-08 13:34:30 +01:00
Rafael J. Wysocki
0b2a1a3938 driver core: class: Clear private pointer on registration failures
Clear the class private pointer if __class_register() fails for it, so
as to allow its users to verify that the class is usable by checking
the value of that pointer.

For consistency, clear that pointer before freeing the object pointed
to by it in class_release().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/4463268.LvFx2qVVIh@kreacher
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-23 14:47:18 +01:00
Greg Kroah-Hartman
7bbb89b420 driver core: change to_subsys_private() to use container_of_const()
The macro to_subsys_private() needs to switch to using
container_of_const() as it turned out to being incorrectly casting a
const pointer to a non-const one.  Make this change and fix up the one
offending user to be correctly handling a const pointer properly.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230111093327.3955063-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-11 16:10:09 +01:00
Greg Kroah-Hartman
02a476d932 kobject: make kobject_get_ownership() take a constant kobject *
The call, kobject_get_ownership(), does not modify the kobject passed
into it, so make it const.  This propagates down into the kobj_type
function callbacks so make the kobject passed into them also const,
ensuring that nothing in the kobject is being changed here.

This helps make it more obvious what calls and callbacks do, and do not,
modify structures passed to them.

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: linux-nfs@vger.kernel.org
Cc: bridge@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20221121094649.1556002-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-22 17:34:29 +01:00
Yang Yingliang
8c3e8a6bdb class: fix possible memory leak in __class_register()
If class_add_groups() returns error, the 'cp->subsys' need be
unregister, and the 'cp' need be freed.

We can not call kset_unregister() here, because the 'cls' will
be freed in callback function class_release() and it's also
freed in caller's error path, it will cause double free.

So fix this by calling kobject_del() and kfree_const(name) to
cleanup kobject. Besides, call kfree() to free the 'cp'.

Fault injection test can trigger this:

unreferenced object 0xffff888102fa8190 (size 8):
  comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
  hex dump (first 8 bytes):
    70 6b 74 63 64 76 64 00                          pktcdvd.
  backtrace:
    [<00000000e7c7703d>] __kmalloc_track_caller+0x1ae/0x320
    [<000000005e4d70bc>] kstrdup+0x3a/0x70
    [<00000000c2e5e85a>] kstrdup_const+0x68/0x80
    [<000000000049a8c7>] kvasprintf_const+0x10b/0x190
    [<0000000029123163>] kobject_set_name_vargs+0x56/0x150
    [<00000000747219c9>] kobject_set_name+0xab/0xe0
    [<0000000005f1ea4e>] __class_register+0x15c/0x49a

unreferenced object 0xffff888037274000 (size 1024):
  comm "modprobe", pid 502, jiffies 4294906074 (age 49.296s)
  hex dump (first 32 bytes):
    00 40 27 37 80 88 ff ff 00 40 27 37 80 88 ff ff  .@'7.....@'7....
    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
  backtrace:
    [<00000000151f9600>] kmem_cache_alloc_trace+0x17c/0x2f0
    [<00000000ecf3dd95>] __class_register+0x86/0x49a

Fixes: ced6473e74 ("driver core: class: add class_groups support")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221026082803.3458760-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 14:58:29 +01:00
Yang Yingliang
e9628e015f class: use IS_ERR_OR_NULL() helper in class_unregister()
Use IS_ERR_OR_NULL() helper in class_unregister() to simplify code.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220822061922.3884113-1-yangyingliang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-01 18:15:40 +02:00
Christoph Hellwig
322cbb50de block: remove genhd.h
There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it.  So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02 07:49:59 -07:00
Mauro Carvalho Chehab
33c0c9bdf7 drivers: base: fix some kernel-doc markups
class_create is actually defined at the header. Fix the
markup there and add a new one at the right place.

While here, also fix some markups for functions that have
different names between their prototypes and kernel-doc
comments.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/2fb6efd6a1f90d69ff73bf579566079cbb051e15.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-09 18:56:49 +01:00
Joe Perches
948b3edba8 drivers core: Miscellaneous changes for sysfs_emit
Change additional instances that could use sysfs_emit and sysfs_emit_at
that the coccinelle script could not convert.

o macros creating show functions with ## concatenation
o unbound sprintf uses with buf+len for start of output to sysfs_emit_at
o returns with ?: tests and sprintf to sysfs_emit
o sysfs output with struct class * not struct device * arguments

Miscellanea:

o remove unnecessary initializations around these changes
o consistently use int len for return length of show functions
o use octal permissions and not S_<FOO>
o rename a few show function names so DEVICE_ATTR_<FOO> can be used
o use DEVICE_ATTR_ADMIN_RO where appropriate
o consistently use const char *output for strings
o checkpatch/style neatening

Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/8bc24444fe2049a9b2de6127389b57edfdfe324d.1600285923.git.joe@perches.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-02 13:12:07 +02:00
Greg Kroah-Hartman
a8ae608529 device.h: move 'struct class' stuff out to device/class.h
device.h has everything and the kitchen sink when it comes to struct
device things, so split out the struct class things things to a separate
.h file to make things easier to maintain and manage over time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20191209193303.1694546-6-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-16 10:11:14 +01:00
Wei Yang
570d020012 driver core: move device->knode_class to device_private
As the description of struct device_private says, it stores data which
is private to driver core. And it already has similar fields like:
knode_parent, knode_driver, knode_driver and knode_bus. This look it is
more proper to put knode_class together with those fields to make it
private to driver core.

This patch move device->knode_class to device_private to make it comply
with code convention.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18 16:55:48 +01:00
Greg Kroah-Hartman
3282570990 driver core: Remove redundant license text
Now that the SPDX tag is in all driver core files, that identifies the
license in a specific and legally-defined manner.  So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:36:44 +01:00
Greg Kroah-Hartman
989d42e85d driver core: add SPDX identifiers to all driver core files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core files files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:36:43 +01:00
Greg Kroah-Hartman
ecbaa83ee8 driver core: remove class_attrs from struct class
This field is no longer used or needed (use class_groups instead), so it
can be removed along with the driver core functionality that created and
removed these files.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 10:41:00 +02:00
Greg Kroah-Hartman
ced6473e74 driver core: class: add class_groups support
struct class needs to have a set of default groups that are added, as
adding individual attributes does not work well in the long run.  So add
support for that.

Future patches will convert the existing usages of class_attrs to use
class_groups and then class_attrs will go away.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-29 21:12:12 +01:00
Rolf Eike Beer
1207775428 class_find_device: fix reference to argument "match"
There is no argument "fn".

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-09-29 15:23:14 +02:00
Cosmin Tomulescu
d34898de9a drivers: base: class: Add a blank line after declarations
This patch fixes the following warning found by checkpatch.pl:
WARNING: Missing a black line after declarations

Signed-off-by: Cosmin Tomulescu <cosmintom@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 14:36:19 +01:00
Tejun Heo
58292cbe66 sysfs: make attr namespace interface less convoluted
sysfs ns (namespace) implementation became more convoluted than
necessary while trying to hide ns information from visible interface.
The relatively recent attr ns support is a good example.

* attr ns tag is determined by sysfs_ops->namespace() callback while
  dir tag is determined by kobj_type->namespace().  The placement is
  arbitrary.

* Instead of performing operations with explicit ns tag, the namespace
  callback is routed through sysfs_attr_ns(), sysfs_ops->namespace(),
  class_attr_namespace(), class_attr->namespace().  It's not simpler
  in any sense.  The only thing this convolution does is traversing
  the whole stack backwards.

The namespace callbacks are unncessary because the operations involved
are inherently synchronous.  The information can be provided in in
straight-forward top-down direction and reversing that direction is
unnecessary and against basic design principles.

This backward interface is unnecessarily convoluted and hinders
properly separating out sysfs from driver model / kobject for proper
layering.  This patch updates attr ns support such that

* sysfs_ops->namespace() and class_attr->namespace() are dropped.

* sysfs_{create|remove}_file_ns(), which take explicit @ns param, are
  added and sysfs_{create|remove}_file() are now simple wrappers
  around the ns aware functions.

* ns handling is dropped from sysfs_chmod_file().  Nobody uses it at
  this point.  sysfs_chmod_file_ns() can be added later if necessary.

* Explicit @ns is propagated through class_{create|remove}_file_ns()
  and netdev_class_{create|remove}_file_ns().

* driver/net/bonding which is currently the only user of attr
  namespace is updated to use netdev_class_{create|remove}_file_ns()
  with @bh->net as the ns tag instead of using the namespace callback.

This patch should be an equivalent conversion without any functional
difference.  It makes the code easier to follow, reduces lines of code
a bit and helps proper separation and layering.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 14:50:01 -07:00
Greg Kroah-Hartman
3e1026b3fa sysfs.h: remove attr_name() macro
Gotta love a macro that doesn't reduce the typing you have to do.

Also, only the driver core, and one network driver uses this.  The
driver core functions will be going away soon, and I'll convert the
network driver soon to not need this as well, so delete it for now
before anyone else gets some bright ideas and wants to use it.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-22 10:25:34 -07:00
Michał Mirosław
9f3b795a62 driver-core: constify data for class_find_device()
All in-kernel users of class_find_device() don't really need mutable
data for match callback.

In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.

The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.

Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-06 12:18:56 -08:00
Kay Sievers
ca22e56deb driver-core: implement 'sysdev' functionality for regular devices and buses
All sysdev classes and sysdev devices will converted to regular devices
and buses to properly hook userspace into the event processing.

There is no interesting difference between a 'sysdev' and 'device' which
would justify to roll an entire own subsystem with different userspace
export semantics. Userspace relies on events and generic sysfs subsystem
infrastructure from sysdev devices, which are currently not properly
available.

Every converted sysdev class will create a regular device with the class
name in /sys/devices/system and all registered devices will becom a children
of theses devices.

For compatibility reasons, the sysdev class-wide attributes are created
at this parent device. (Do not copy that logic for anything new, subsystem-
wide properties belong to the subsystem, not to some fake parent device
created in /sys/devices.)

Every sysdev driver is implemented as a simple subsystem interface now,
and no longer called a driver.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-14 14:29:38 -08:00
Eric W. Biederman
672d82c18d class: Implement support for class attrs in tagged sysfs directories.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19 19:24:15 -04:00
Kay Sievers
6b6e39a6a8 driver-core: merge private parts of class and bus
As classes and busses are pretty much the same thing, and we want to
merge them together into a 'subsystem' in the future, let us share the
same private data parts to make that merge easier.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-17 14:21:08 -08:00
Brandon Philips
319684b1cd driver core: fix whitespace in class_attr_string
869dfc875e addded a long line and indented with spaces. Fix.

Signed-off-by: Brandon Philips <brandon@ifup.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-11-10 17:00:12 -08:00
Andi Kleen
e52eec13cd SYSFS: Allow boot time switching between deprecated and modern sysfs layout
I have some systems which need legacy sysfs due to old tools that are
making assumptions that a directory can never be a symlink to another
directory, and it's a big hazzle to compile separate kernels for them.

This patch turns CONFIG_SYSFS_DEPRECATED into a run time option
that can be switched on/off the kernel command line. This way
the same binary can be used in both cases with just a option
on the command line.

The old CONFIG_SYSFS_DEPRECATED_V2 option is still there to set
the default. I kept the weird name to not break existing
config files.

Also the compat code can be still completely disabled by undefining
CONFIG_SYSFS_DEPRECATED_SWITCH -- just the optimizer takes
care of this now instead of lots of ifdefs. This makes the code
look nicer.

v2: This is an updated version on top of Kay's patch to only
handle the block devices. I tested it on my old systems
and that seems to work.

Cc: axboe@kernel.dk
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-22 10:16:43 -07:00