kernel/linux.git/include/linux/device/class.h, branch v6.6.132

driver core: class: properly reference count class_dev_iter()

2023-05-19T10:03:36+00:00

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: 7b884b7f24b4 ("driver core: class.c: convert to only use class_to_subsys") Reported-by: Mirsad Goran Todorovac Cc: Alan Stern Acked-by: Rafael J. Wysocki Tested-by: Mirsad Goran Todorovac Link: https://lore.kernel.org/r/2023051610-stove-condense-9a77@gregkh Signed-off-by: Greg Kroah-Hartman

driver core: class: remove struct class_interface * from callbacks

2023-04-03T19:42:52+00:00

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 Cc: Guenter Roeck Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Kurt Schwemmer Cc: Jon Mason Cc: Dave Jiang Cc: Allen Hubbe Cc: Dominik Brodowski Cc: Matt Porter Cc: Alexandre Bounine Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Doug Gilbert Cc: John Stultz Cc: Thomas Gleixner Cc: Stephen Boyd Cc: Hans de Goede Cc: Andrew Morton Cc: Wang Weiyang Cc: Yang Yingliang Cc: Jakob Koschel Cc: Cai Xinchen Acked-by: Rafael J. Wysocki Acked-by: Logan Gunthorpe Link: https://lore.kernel.org/r/2023040250-pushover-platter-509c@gregkh Signed-off-by: Greg Kroah-Hartman

driver core: class: mark the struct class in struct class_interface constant

2023-04-03T19:42:48+00:00

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 Link: https://lore.kernel.org/r/2023040249-handball-gruffly-5da7@gregkh Signed-off-by: Greg Kroah-Hartman

driver core: class: make class_register() take a const *

2023-04-03T19:42:46+00:00

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 Link: https://lore.kernel.org/r/2023040248-customary-release-4aec@gregkh Signed-off-by: Greg Kroah-Hartman

driver core: class: mark class_release() as taking a const *

2023-04-03T19:42:43+00:00

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 Link: https://lore.kernel.org/r/2023040248-outrage-obsolete-5a9a@gregkh Signed-off-by: Greg Kroah-Hartman

driver core: make sysfs_dev_block_kobj static

2023-03-31T15:45:15+00:00

Nothing outside of drivers/base/core.c uses sysfs_dev_block_kobj, so make it static and document what it is used for so we remember it the next time we touch it 15 years from now. Acked-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20230331093318.82288-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: class: remove dev_kobj from struct class

2023-03-31T15:45:11+00:00

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 Link: https://lore.kernel.org/r/20230331093318.82288-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: class: remove subsystem private pointer from struct class

2023-03-31T15:45:03+00:00

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 Link: https://lore.kernel.org/r/20230331093318.82288-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: create class_is_registered()

2023-03-31T15:44:54+00:00

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 Cc: Sebastian Reichel Cc: Benjamin Tissoires Cc: linux-gpio@vger.kernel.org Reviewed-by: Linus Walleij Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20230331093318.82288-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

driver core: class: mark the struct class for sysfs callbacks as constant

2023-03-29T05:54:58+00:00

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" Cc: "Rafael J. Wysocki" Cc: Bartosz Golaszewski Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Jens Axboe Cc: Johannes Berg Cc: Linus Walleij Cc: Minchan Kim Cc: Miquel Raynal Cc: Namjae Jeon Cc: Paolo Abeni Cc: Russ Weight Cc: Sergey Senozhatsky Cc: Steve French Cc: Vignesh Raghavendra 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 Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman