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2025-01-10drivers: core: remove device_link argument from ↵Heiner Kallweit
class_compat_[create|remove]_link After 7e722083fcc3 ("i2c: Remove I2C_COMPAT config symbol and related code") there's no caller left passing a non-null device_link argument. So remove this argument to simplify the code. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Link: https://lore.kernel.org/r/db49131d-fd79-4f23-93f2-0ab541a345fa@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: Introduce device_iter_t for device iterating APIsZijun Hu
There are several for_each APIs which has parameter with type below: int (*fn)(struct device *dev, void *data) They iterate over various device lists and call @fn() for each device with caller provided data @*data, and they usually need to modify @*data. Give the type an dedicated typedef with advantages shown below: typedef int (*device_iter_t)(struct device *dev, void *data) - Shorter API declarations and definitions - Prevent further for_each APIs from using bad parameter type So introduce device_iter_t and apply it to various existing APIs below: bus_for_each_dev() (class|driver)_for_each_device() device_for_each_child(_reverse|_reverse_from)(). Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-7-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10driver core: class: Fix wild pointer dereferences in API class_dev_iter_next()Zijun Hu
There are a potential wild pointer dereferences issue regarding APIs class_dev_iter_(init|next|exit)(), as explained by below typical usage: // All members of @iter are wild pointers. struct class_dev_iter iter; // class_dev_iter_init(@iter, @class, ...) checks parameter @class for // potential class_to_subsys() error, and it returns void type and does // not initialize its output parameter @iter, so caller can not detect // the error and continues to invoke class_dev_iter_next(@iter) even if // @iter still contains wild pointers. class_dev_iter_init(&iter, ...); // Dereference these wild pointers in @iter here once suffer the error. while (dev = class_dev_iter_next(&iter)) { ... }; // Also dereference these wild pointers here. class_dev_iter_exit(&iter); Actually, all callers of these APIs have such usage pattern in kernel tree. Fix by: - Initialize output parameter @iter by memset() in class_dev_iter_init() and give callers prompt by pr_crit() for the error. - Check if @iter is valid in class_dev_iter_next(). Fixes: 7b884b7f24b4 ("driver core: class.c: convert to only use class_to_subsys") Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20250105-class_fix-v6-1-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-12driver core: class: Correct WARN() message in APIs ↵Zijun Hu
class_(for_each|find)_device() For both API class_for_each_device(const struct class *class, ...) and class_find_device(const struct class *class, ...), their WARN() messages prompt @class was not initialized when suffer class_to_subsys(@class) error, but the error actually means @class was not registered, so these warning messages are not accurate. Fix by replacing term initialized with registered within these messages. Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20241105-class_fix-v1-2-80866f9994a5@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03driver core: class: Check namespace relevant parameters in class_register()Zijun Hu
Device class has two namespace relevant fields which are usually associated by the following usage: struct class { ... const struct kobj_ns_type_operations *ns_type; const void *(*namespace)(const struct device *dev); ... } if (dev->class && dev->class->ns_type) dev->class->namespace(dev); (1) The usage looks weird since it checks @ns_type but calls namespace() (2) The usage implies both fields have dependency but their dependency is not currently enforced yet. It is found for all existing class definitions that the other filed is also assigned once one is assigned in current kernel tree. Fixed by enforcing above existing dependency that both fields are required for a device class to support namespace via parameter checks. Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240822-class_fix-v1-1-2a6d38ba913a@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03drivers/base: Introduce device_match_t for device finding APIsZijun Hu
There are several drivers/base APIs for finding a specific device, and they currently use the following good type for the @match parameter: int (*match)(struct device *dev, const void *data) Since these operations do not modify the caller-provided @*data, this type is worthy of a dedicated typedef: typedef int (*device_match_t)(struct device *dev, const void *data) Advantages of using device_match_t: - Shorter API declarations and definitions - Prevent further APIs from using a bad type for @match So introduce device_match_t and apply it to the existing (bus|class|driver|auxiliary)_find_device() APIs. Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Link: https://lore.kernel.org/r/20240813-dev_match_api-v3-1-6c6878a99b9f@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04class: fix use-after-free in class_register()Jing Xia
The lock_class_key is still registered and can be found in lock_keys_hash hlist after subsys_private is freed in error handler path.A task who iterate over the lock_keys_hash later may cause use-after-free.So fix that up and unregister the lock_class_key before kfree(cp). On our platform, a driver fails to kset_register because of creating duplicate filename '/class/xxx'.With Kasan enabled, it prints a invalid-access bug report. KASAN bug report: BUG: KASAN: invalid-access in lockdep_register_key+0x19c/0x1bc Write of size 8 at addr 15ffff808b8c0368 by task modprobe/252 Pointer tag: [15], memory tag: [fe] CPU: 7 PID: 252 Comm: modprobe Tainted: G W 6.6.0-mainline-maybe-dirty #1 Call trace: dump_backtrace+0x1b0/0x1e4 show_stack+0x2c/0x40 dump_stack_lvl+0xac/0xe0 print_report+0x18c/0x4d8 kasan_report+0xe8/0x148 __hwasan_store8_noabort+0x88/0x98 lockdep_register_key+0x19c/0x1bc class_register+0x94/0x1ec init_module+0xbc/0xf48 [rfkill] do_one_initcall+0x17c/0x72c do_init_module+0x19c/0x3f8 ... Memory state around the buggy address: ffffff808b8c0100: 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a 8a ffffff808b8c0200: 8a 8a 8a 8a 8a 8a 8a 8a fe fe fe fe fe fe fe fe >ffffff808b8c0300: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ ffffff808b8c0400: 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 03 As CONFIG_KASAN_GENERIC is not set, Kasan reports invalid-access not use-after-free here.In this case, modprobe is manipulating the corrupted lock_keys_hash hlish where lock_class_key is already freed before. It's worth noting that this only can happen if lockdep is enabled, which is not true for normal system. Fixes: dcfbb67e48a2 ("driver core: class: use lock_class_key already present in struct subsys_private") Cc: stable <stable@kernel.org> Signed-off-by: Jing Xia <jing.xia@unisoc.com> Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Link: https://lore.kernel.org/r/20231220024603.186078-1-jing.xia@unisoc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-21driver core: class: remove boilerplate codeMaurizio Lombardi
Jump to err_out to avoid duplicating the code. Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Link: https://lore.kernel.org/r/20231020160042.759439-1-mlombard@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-19driver core: class: properly reference count class_dev_iter()Greg Kroah-Hartman
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 <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>
2023-04-03driver core: class: remove struct class_interface * from callbacksGreg Kroah-Hartman
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>
2023-04-03driver core: class: mark the struct class in struct class_interface constantGreg Kroah-Hartman
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>
2023-04-03driver core: class: make class_register() take a const *Greg Kroah-Hartman
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>
2023-04-03driver core: class: mark class_release() as taking a const *Greg Kroah-Hartman
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>
2023-04-01driver core: class: fix slab-use-after-free Read in class_register()Greg Kroah-Hartman
Syzbot found that we had forgotten to unregister the lock_class_key when using it in commit dcfbb67e48a2 ("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: dcfbb67e48a2 ("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>
2023-03-31driver core: class: remove dev_kobj from struct classGreg Kroah-Hartman
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>
2023-03-31driver core: class: remove subsystem private pointer from struct classGreg Kroah-Hartman
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>
2023-03-31driver core: create class_is_registered()Greg Kroah-Hartman
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>
2023-03-31driver core: core: move to use class_to_subsys()Greg Kroah-Hartman
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>
2023-03-29driver core: class.c: convert to only use class_to_subsysGreg Kroah-Hartman
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>
2023-03-29driver core: class: implement class_get/put without the private pointer.Greg Kroah-Hartman
Much like what was done in commit 273afac615ad ("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>
2023-03-29driver core: class: mark the struct class for sysfs callbacks as constantGreg Kroah-Hartman
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>
2023-03-28driver core: bus: constify class_unregister/destroy()Greg Kroah-Hartman
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>
2023-03-27driver core: class: fix documentation for class_create()Greg Kroah-Hartman
In commit dcfbb67e48a2 ("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: dcfbb67e48a2 ("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>
2023-03-24driver core: class: use lock_class_key already present in struct subsys_privateGreg Kroah-Hartman
In commit 37e98d9bedb5 ("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>
2023-03-17driver core: class: make class_create/remove_file*() options constGreg Kroah-Hartman
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>
2023-03-17driver core: class: make class_find_device*() options constGreg Kroah-Hartman
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>
2023-03-17driver core: class: make class_for_each_device() options constGreg Kroah-Hartman
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>
2023-03-17driver core: class: make class_dev_iter_init() options constGreg Kroah-Hartman
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>
2023-03-17driver core: class: remove struct module owner out of struct classGreg Kroah-Hartman
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>
2023-03-17driver core: class: specify the module owner in __class_register()Greg Kroah-Hartman
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>
2023-03-07driver core: class: fix block class problem when removing ↵Greg Kroah-Hartman
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: 721da5cee9d4 ("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>
2023-03-06driver core: remove CONFIG_SYSFS_DEPRECATED and CONFIG_SYSFS_DEPRECATED_V2Greg Kroah-Hartman
CONFIG_SYSFS_DEPRECATED was added in commit 88a22c985e35 ("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 e52eec13cd6b ("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>
2023-02-14driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct placeGreg Kroah-Hartman
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>
2023-02-08driver core: make kobj_type structures constantThomas Weißschuh
Since commit ee6d3dd4ed48 ("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>
2023-01-23driver core: class: Clear private pointer on registration failuresRafael J. Wysocki
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>
2023-01-11driver core: change to_subsys_private() to use container_of_const()Greg Kroah-Hartman
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>
2022-11-22kobject: make kobject_get_ownership() take a constant kobject *Greg Kroah-Hartman
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>
2022-11-09class: fix possible memory leak in __class_register()Yang Yingliang
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: ced6473e7486 ("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>
2022-09-01class: use IS_ERR_OR_NULL() helper in class_unregister()Yang Yingliang
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>
2022-02-02block: remove genhd.hChristoph Hellwig
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>
2020-11-09drivers: base: fix some kernel-doc markupsMauro Carvalho Chehab
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>
2020-10-02drivers core: Miscellaneous changes for sysfs_emitJoe Perches
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>
2019-12-16device.h: move 'struct class' stuff out to device/class.hGreg Kroah-Hartman
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>
2019-01-18driver core: move device->knode_class to device_privateWei Yang
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>
2017-12-07driver core: Remove redundant license textGreg Kroah-Hartman
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>
2017-12-07driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman
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>
2017-06-09driver core: remove class_attrs from struct classGreg Kroah-Hartman
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>
2016-11-29driver core: class: add class_groups supportGreg Kroah-Hartman
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>
2015-09-29class_find_device: fix reference to argument "match"Rolf Eike Beer
There is no argument "fn". Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-03-25drivers: base: class: Add a blank line after declarationsCosmin Tomulescu
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>