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path: root/drivers/base/bus.c
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* driver core: bus: Handle early calls to bus_to_subsys()Geert Uytterhoeven2023-02-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When calling soc_device_match() from early_initcall(), bus_kset is still NULL, causing a crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028 ... Call trace: __lock_acquire+0x530/0x20f0 lock_acquire.part.0+0xc8/0x210 lock_acquire+0x64/0x80 _raw_spin_lock+0x4c/0x60 bus_to_subsys+0x24/0xac bus_for_each_dev+0x30/0xcc soc_device_match+0x4c/0xe0 r8a7795_sysc_init+0x18/0x60 rcar_sysc_pd_init+0xb0/0x33c do_one_initcall+0x128/0x2bc Before, bus_for_each_dev() handled this gracefully by checking that the back-pointer to the private structure was valid. Fix this by adding a NULL check for bus_kset to bus_to_subsys(). Fixes: 83b9148df2c95e23 ("driver core: bus: bus iterator cleanups") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lore.kernel.org/r/0a92979f6e790737544638e8a4c19b0564e660a2.1676983596.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: update my copyright noticeGreg Kroah-Hartman2023-02-101-0/+1
| | | | | | | | | | There's been some work done recently to the drivers/base/bus.c file so update the copyright notice in it to make those who track those types of things have an easier job. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230210091318.733561-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: add bus_get_dev_root() functionGreg Kroah-Hartman2023-02-101-0/+20
| | | | | | | | | | | | | | Instead of poking around in the struct bus_type directly for the dev_root pointer, provide a function to return it properly reference counted, if it is present in the bus. This will be needed to move the pointer out of struct bus_type in the future. Use the function in the driver core code at the same time it is introduced to verify that it works properly. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230209093556.19132-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: constify bus_unregister()Greg Kroah-Hartman2023-02-091-1/+1
| | | | | | | | | The bus_unregister() function can now take a const * to bus_type, not just a * so fix that up. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-22-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: constify some internal functionsGreg Kroah-Hartman2023-02-091-2/+2
| | | | | | | | | | | | The functions add_probe_files() and remove_probe_files() should be taking a const * to bus_type, not just a *, so fix that up. These functions should really be removed entirely and an attribute group used instead, but for now, make this change so that other const work can continue. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-21-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: constify bus_get_kset()Greg Kroah-Hartman2023-02-091-1/+1
| | | | | | | | | The bus_get_kset() function should be taking a const * to bus_type, not just a * so fix that up. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-20-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: constify bus_register/unregister_notifier()Greg Kroah-Hartman2023-02-091-2/+2
| | | | | | | | | The bus_register_notifier() and bus_unregister_notifier() functions should be taking a const * to bus_type, not just a * so fix that up. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-19-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: remove private pointer from struct bus_typeGreg Kroah-Hartman2023-02-091-4/+0
| | | | | | | | | | | | Now that the driver code has been refactored to not rely on the pointer from a struct bus_type to the private structure it can be safely removed from the structure entirely. This will allow most bus_type structures to now be marked as const. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-18-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: create bus_is_registered()Greg Kroah-Hartman2023-02-091-0/+16
| | | | | | | | | | | A local function to the driver core to determine if a bus really is registered with the kernel or not. To be used only by the driver core code, as part of the driver registration path as it's not really "safe" because the bus could be unregistered instantly after being called. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-17-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: clean up driver_find()Greg Kroah-Hartman2023-02-091-8/+15
| | | | | | | | | Convert the driver_find() function to use bus_to_subsys() and not use the back-pointer to the private structure. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: move driver_find() to bus.cGreg Kroah-Hartman2023-02-091-0/+27
| | | | | | | | | | This function really is a bus function, not a driver one, so move it from driver.c to bus.c so that we can clean up some internal bus logic easier. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-15-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: clean up bus_sort_breadthfirst()Greg Kroah-Hartman2023-02-091-6/+5
| | | | | | | | | | | | Convert the bus_sort_breadthfirst() function to use bus_to_subsys() and not use the back-pointer to the private structure. This also allows us to get rid of bus_get_device_klist() which was only being used by this one internal function. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-14-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: bus iterator cleanupsGreg Kroah-Hartman2023-02-091-6/+12
| | | | | | | | | | Convert the bus_for_each_dev(), bus_find_device, and bus_for_each_drv() functions to use bus_to_subsys() and not use the back-pointer to the private structure. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-13-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: bus_add/remove_driver() cleanupsGreg Kroah-Hartman2023-02-091-13/+26
| | | | | | | | | Convert the bus_add_driver() and bus_remove_driver() functions to use bus_to_subsys() and not use the back-pointer to the private structure. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-12-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: bus_register/unregister_notifier() cleanupsGreg Kroah-Hartman2023-02-091-5/+23
| | | | | | | | | | Convert the bus_register_notifier() and bus_unregister_notifier() public functions to use bus_to_subsys() and not use the back-pointer to the private structure as well as the bus_notify() function. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-11-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: bus_get_kset() cleanupGreg Kroah-Hartman2023-02-091-1/+10
| | | | | | | | | Convert the bus_get_kset() function function to use bus_to_subsys() and not use the back-pointer to the private structure. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-10-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: subsys_interface_register/unregister() cleanupsGreg Kroah-Hartman2023-02-091-16/+29
| | | | | | | | | | | | | Convert the subsys_interface_register and subsys_interface_unregister() functions to use bus_to_subsys() and not use the back-pointer to the private structure. This also requires changing the parameters on subsys_dev_iter_init() to iterate over the list properly. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-9-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: bus_register/unregister() cleanupsGreg Kroah-Hartman2023-02-091-28/+26
| | | | | | | | | | | | | | Convert the bus_register() and bus_unregister() functions to use bus_to_subsys() and not use the back-pointer to the private structure. Because bus_add_groups() and bus_remove_groups() were only called in one place, remove those one-line-wrapper functions and call the real sysfs group function where it is needed instead, saving another layer of indirection. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-8-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: bus_add/probe/remove_device() cleanupsGreg Kroah-Hartman2023-02-091-33/+54
| | | | | | | | | | Convert the bus_add_device(), bus_probe_device(), and bus_remove_device() functions to use bus_to_subsys() and not use the back-pointer to the private structure. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-7-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: sysfs function cleanupsGreg Kroah-Hartman2023-02-091-6/+29
| | | | | | | | | | Convert the drivers_autoprobe show/store and uevent sysfs callbacks to use bus_to_subsys() and not use the back-pointer to the private structure. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: convert bus_create/remove_file to be constantGreg Kroah-Hartman2023-02-091-11/+17
| | | | | | | | | | | | bus_create_file() and bus_remove_file() can be made to take a constant bus pointer, as it should not be modifying anything in the bus structure. Make this change and move the functions to use the internal subsys_get/put() logic as well, to prevent the use of the back-pointer in struct bus_type. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: constantify the bus_find_* functionsGreg Kroah-Hartman2023-02-091-3/+3
| | | | | | | | | All of the bus find and iterator functions do not modify the struct bus_type passed to them, so mark them as constant to enforce this rule. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: implement bus_get/put() without the private pointerGreg Kroah-Hartman2023-02-091-8/+53
| | | | | | | | | | | | | | | | | | | In the quest to make 'struct bus_type' constant and in read-only memory, we need to stop using the private pointer to the subsys_private structure. First step in doing this is to create a helper function that turns a 'struct bus_type' into 'struct subsys_private' called bus_to_subsys(). bus_to_subsys() walks the list of registered busses in the system and finds the matching one based on the pointer to the bus_type itself. As this is a short list, and this function is not on any fast path, it should not be noticable. Implement bus_get() and bus_put() using this new helper function. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230208111330.439504-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: make kobj_type structures constantThomas Weißschuh2023-02-081-2/+2
| | | | | | | | | | | | 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>
* driver core: bus: move lock_class_key into dynamic structureGreg Kroah-Hartman2023-02-011-1/+4
| | | | | | | | | | | | | | | | | | | Move the lock_class_key structure out of struct bus_type and into the dynamic structure we create already for all bus_types registered with the kernel. This saves on static space and removes one more writable field in struct bus_type. In the future, the same field can be moved out of the struct class logic because it shares this same private structure. Most everyone will never notice this change, as lockdep is not enabled in real systems so no memory or logic changes are happening for them. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20230201083349.4038660-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: move bus notifier logic into bus.cGreg Kroah-Hartman2023-01-181-0/+8
| | | | | | | | | | | The logic to touch the bus notifier was open-coded in numberous places in the driver core. Clean that up by creating a local bus_notify() function and have everyone call this function instead, making the reading of the caller code simpler and easier to maintain over time. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230111092331.3946745-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: move struct subsys_dev_iter to a local fileGreg Kroah-Hartman2023-01-101-0/+5
| | | | | | | | | | struct subsys_dev_iter is not used by any code outside of drivers/base/bus.c so move it into that file and out of the global bus.h file. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230109175810.2965448-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: make subsys_dev_iter_exit() staticGreg Kroah-Hartman2023-01-101-2/+1
| | | | | | | | | | The function subsys_dev_iter_exit() is not used outside of drivers/base/bus.c so make it static to that file and remove the global export. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230109175810.2965448-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: make subsys_dev_iter_next() staticGreg Kroah-Hartman2023-01-101-2/+1
| | | | | | | | | The function subsys_dev_iter_next() is only used in drivers/base/bus.c so make it static to that file and remove the global export. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230109175810.2965448-4-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: make subsys_dev_iter_init() staticGreg Kroah-Hartman2023-01-101-3/+2
| | | | | | | | | No one outside of drivers/base/bus.c calls this function so make it static and remove the exported symbol. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230109175810.2965448-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: remove subsys_find_device_by_id()Greg Kroah-Hartman2023-01-101-41/+0
| | | | | | | | | This function has not been called by any code in the kernel tree in many many years so remove it as it is unused. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230109175810.2965448-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: make bus_get_device_klist() staticGreg Kroah-Hartman2023-01-101-2/+1
| | | | | | | | | No one calls this function outside of drivers/base/bus.c so make it static so it does not need to be exported anymore. Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Link: https://lore.kernel.org/r/20230109175810.2965448-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: kset_uevent_ops: make filter() callback take a const *Greg Kroah-Hartman2022-11-221-1/+1
| | | | | | | | | | | | | | | | The filter() callback in struct kset_uevent_ops does not modify the kobject passed into it, so make the pointer const to enforce this restriction. When doing so, fix up all existing filter() callbacks to have the correct signature to preserve the build. Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Christian König <christian.koenig@amd.com> for the changes to Link: https://lore.kernel.org/r/20221121094649.1556002-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver: base: fix UAF when driver_attach failedSchspa Shi2022-05-191-1/+3
| | | | | | | | | | | | When driver_attach(drv); failed, the driver_private will be freed. But it has been added to the bus, which caused a UAF. To fix it, we need to delete it from the bus when failed. Fixes: 190888ac01d0 ("driver core: fix possible missing of device probe") Signed-off-by: Schspa Shi <schspa@gmail.com> Link: https://lore.kernel.org/r/20220513112444.45112-1-schspa@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: remove kset from struct kset_uevent_ops callbacksGreg Kroah-Hartman2021-12-281-1/+1
| | | | | | | | | | | There is no need to pass the pointer to the kset in the struct kset_uevent_ops callbacks as no one uses it, so just remove that pointer entirely. Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@google.com> Link: https://lore.kernel.org/r/20211227163924.3970661-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: make kobj_type constant.Wedson Almeida Filho2021-12-271-1/+1
| | | | | | | | | | This way instances of kobj_type (which contain function pointers) can be stored in .rodata, which means that they cannot be [easily/accidentally] modified at runtime. Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Link: https://lore.kernel.org/r/20211224231345.777370-1-wedsonaf@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver: base: Replace symbolic permissions with octal permissionsJinchao Wang2021-07-211-3/+3
| | | | | | | | | Resolve following checkpatch issue, Replace symbolic permissions with octal permissions Signed-off-by: Jinchao Wang <wjc@cdjrlc.com> Link: https://lore.kernel.org/r/20210626094606.53152-1-wjc@cdjrlc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Flow the return code from ->probe() through to sysfs bindChristoph Hellwig2021-06-211-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Currently really_probe() returns 1 on success and 0 if the probe() call fails. This return code arrangement is designed to be useful for __device_attach_driver() which is walking the device list and trying every driver. 0 means to keep trying. However, it is not useful for the other places that call through to really_probe() that do actually want to see the probe() return code. For instance bind_store() would be better to return the actual error code from the driver's probe method, not discarding it and returning -ENODEV. Reorganize things so that really_probe() returns the error code from ->probe as a (inverted) positive number, and 0 for successful attach. With this, __device_attach_driver can ignore the (positive) probe errors, return 1 to exit the loop for a successful binding and pass on the other negative errors, while device_driver_attach simplify inverts the positive errors and returns all errors to the sysfs code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20210617142218.1877096-4-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* driver core: Pull required checks into driver_probe_device()Jason Gunthorpe2021-06-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Checking if the dev is dead or if the dev is already bound is a required precondition to invoking driver_probe_device(). All the call chains leading here duplicate these checks. Add it directly to driver_probe_device() so the precondition is clear and remove the checks from device_driver_attach() and __driver_attach_async_helper(). The other call chain going through __device_attach_driver() does have these same checks but they are inlined into logic higher up the call stack and can't be removed. The sysfs uAPI call chain starting at bind_store() is a bit confused because it reads dev->driver unlocked and returns -ENODEV if it is !NULL, otherwise it reads it again under lock and returns 0 if it is !NULL. Fix this to always return -EBUSY and always read dev->driver under its lock. Done in preparation for the next patches which will add additional callers to driver_probe_device() and will need these checks as well. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> [hch: drop the extra checks in device_driver_attach and bind_store] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/20210617142218.1877096-2-hch@lst.de Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
* drivers: base: change 'driver_create_groups' to 'driver_add_groups' in printkJoe Pater2021-01-271-1/+1
| | | | | | | | | driver_create_groups doesn't seem to have ever existed. Change its mention in a printk to 'driver_add_groups'. Signed-off-by: Joe Pater <02joepater06@gmail.com> Link: https://lore.kernel.org/r/20210110145442.15301-1-02joepater06@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: base: remove unused function find_bus()Joe Pater2021-01-071-17/+0
| | | | | | | | | find_bus() isn't doing anyone any good sitting in a '#if 0' (as it's been doing since 2006!). Signed-off-by: Joe Pater <02joepater06@gmail.com> Link: https://lore.kernel.org/r/20210103203238.111565-1-02joepater06@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers core: Miscellaneous changes for sysfs_emitJoe Perches2020-10-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* device.h: move 'struct bus' stuff out to device/bus.hGreg Kroah-Hartman2019-12-161-0/+1
| | | | | | | | | | | | | device.h has everything and the kitchen sink when it comes to struct device things, so split out the struct bus 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/20191209193303.1694546-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: Introduce device lookup variants by nameSuzuki K Poulose2019-07-301-24/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a helper to match the device name for device lookup. Also reuse this generic exported helper for the existing bus_find_device_by_name(). and add similar variants for driver/class. Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Murphy <dmurphy@ti.com> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Lee Jones <lee.jones@linaro.org> Cc: linux-leds@vger.kernel.org Cc: linux-rtc@vger.kernel.org Cc: linux-usb@vger.kernel.org Cc: linux-wpan@vger.kernel.org Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Stefan Schmidt <stefan@datenfreihafen.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20190723221838.12024-2-suzuki.poulose@arm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bus_find_device: Unify the match callback with class_find_deviceSuzuki K Poulose2019-06-241-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is an arbitrary difference between the prototypes of bus_find_device() and class_find_device() preventing their callers from passing the same pair of data and match() arguments to both of them, which is the const qualifier used in the prototype of class_find_device(). If that qualifier is also used in the bus_find_device() prototype, it will be possible to pass the same match() callback function to both bus_find_device() and class_find_device(), which will allow some optimizations to be made in order to avoid code duplication going forward. Also with that, constify the "data" parameter as it is passed as a const to the match function. For this reason, change the prototype of bus_find_device() to match the prototype of class_find_device() and adjust its callers to use the const qualifier in accordance with the new prototype of it. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Corey Minyard <minyard@acm.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: David Kershner <david.kershner@unisys.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: David Airlie <airlied@linux.ie> Cc: Felipe Balbi <balbi@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Hartmut Knaack <knaack.h@gmx.de> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jonathan Cameron <jic23@kernel.org> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: Len Brown <lenb@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael Jamet <michael.jamet@intel.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Peter Oberparleiter <oberpar@linux.ibm.com> Cc: Sebastian Ott <sebott@linux.ibm.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Cc: rafael@kernel.org Acked-by: Corey Minyard <minyard@acm.org> Acked-by: David Kershner <david.kershner@unisys.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: Probe devices asynchronously instead of the driverAlexander Duyck2019-01-311-20/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Probe devices asynchronously instead of the driver. This results in us seeing the same behavior if the device is registered before the driver or after. This way we can avoid serializing the initialization should the driver not be loaded until after the devices have already been added. The motivation behind this is that if we have a set of devices that take a significant amount of time to load we can greatly reduce the time to load by processing them in parallel instead of one at a time. In addition, each device can exist on a different node so placing a single thread on one CPU to initialize all of the devices for a given driver can result in poor performance on a system with multiple nodes. This approach can reduce the time needed to scan SCSI LUNs significantly. The only way to realize that speedup is by enabling more concurrency which is what is achieved with this patch. To achieve this it was necessary to add a new member "async_driver" to the device_private structure to store the driver pointer while we wait on the deferred probe call. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* device core: Consolidate locking and unlocking of parent and deviceAlexander Duyck2019-01-311-19/+4
| | | | | | | | | | | | | | | | | | | | | Try to consolidate all of the locking and unlocking of both the parent and device when attaching or removing a driver from a given device. To do that I first consolidated the lock pattern into two functions __device_driver_lock and __device_driver_unlock. After doing that I then created functions specific to attaching and detaching the driver while acquiring these locks. By doing this I was able to reduce the number of spots where we touch need_parent_lock from 12 down to 4. This patch should produce no functional changes, it is meant to be a code clean-up/consolidation only. Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: drop use of BUS_ATTR()Greg Kroah-Hartman2019-01-081-1/+8
| | | | | | | | | We are trying to get rid of BUS_ATTR() so drop the last user of it from the tree. We had to "open code" it in order to prevent a function name conflict due to the use of DEVICE_ATTR_WO() earlier in the file :( Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver core: bus: convert to use BUS_ATTR_WO and RWGreg Kroah-Hartman2019-01-081-6/+5
| | | | | | | | | We are trying to get rid of BUS_ATTR() and the usage of that in bus.c can be trivially converted to use BUS_ATTR_WO and RW, so use those macros instead. Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* sysfs: Disable lockdep for driver bind/unbind filesDaniel Vetter2018-12-191-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the much more correct fix for my earlier attempt at: https://lkml.org/lkml/2018/12/10/118 Short recap: - There's not actually a locking issue, it's just lockdep being a bit too eager to complain about a possible deadlock. - Contrary to what I claimed the real problem is recursion on kn->count. Greg pointed me at sysfs_break_active_protection(), used by the scsi subsystem to allow a sysfs file to unbind itself. That would be a real deadlock, which isn't what's happening here. Also, breaking the active protection means we'd need to manually handle all the lifetime fun. - With Rafael we discussed the task_work approach, which kinda works, but has two downsides: It's a functional change for a lockdep annotation issue, and it won't work for the bind file (which needs to get the errno from the driver load function back to userspace). - Greg also asked why this never showed up: To hit this you need to unregister a 2nd driver from the unload code of your first driver. I guess only gpus do that. The bug has always been there, but only with a recent patch series did we add more locks so that lockdep built a chain from unbinding the snd-hda driver to the acpi_video_unregister call. Full lockdep splat: [12301.898799] ============================================ [12301.898805] WARNING: possible recursive locking detected [12301.898811] 4.20.0-rc7+ #84 Not tainted [12301.898815] -------------------------------------------- [12301.898821] bash/5297 is trying to acquire lock: [12301.898826] 00000000f61c6093 (kn->count#39){++++}, at: kernfs_remove_by_name_ns+0x3b/0x80 [12301.898841] but task is already holding lock: [12301.898847] 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190 [12301.898856] other info that might help us debug this: [12301.898862] Possible unsafe locking scenario: [12301.898867] CPU0 [12301.898870] ---- [12301.898874] lock(kn->count#39); [12301.898879] lock(kn->count#39); [12301.898883] *** DEADLOCK *** [12301.898891] May be due to missing lock nesting notation [12301.898899] 5 locks held by bash/5297: [12301.898903] #0: 00000000cd800e54 (sb_writers#4){.+.+}, at: vfs_write+0x17f/0x1b0 [12301.898915] #1: 000000000465e7c2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xd3/0x190 [12301.898925] #2: 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190 [12301.898936] #3: 00000000414ef7ac (&dev->mutex){....}, at: device_release_driver_internal+0x34/0x240 [12301.898950] #4: 000000003218fbdf (register_count_mutex){+.+.}, at: acpi_video_unregister+0xe/0x40 [12301.898960] stack backtrace: [12301.898968] CPU: 1 PID: 5297 Comm: bash Not tainted 4.20.0-rc7+ #84 [12301.898974] Hardware name: Hewlett-Packard HP EliteBook 8460p/161C, BIOS 68SCF Ver. F.01 03/11/2011 [12301.898982] Call Trace: [12301.898989] dump_stack+0x67/0x9b [12301.898997] __lock_acquire+0x6ad/0x1410 [12301.899003] ? kernfs_remove_by_name_ns+0x3b/0x80 [12301.899010] ? find_held_lock+0x2d/0x90 [12301.899017] ? mutex_spin_on_owner+0xe4/0x150 [12301.899023] ? find_held_lock+0x2d/0x90 [12301.899030] ? lock_acquire+0x90/0x180 [12301.899036] lock_acquire+0x90/0x180 [12301.899042] ? kernfs_remove_by_name_ns+0x3b/0x80 [12301.899049] __kernfs_remove+0x296/0x310 [12301.899055] ? kernfs_remove_by_name_ns+0x3b/0x80 [12301.899060] ? kernfs_name_hash+0xd/0x80 [12301.899066] ? kernfs_find_ns+0x6c/0x100 [12301.899073] kernfs_remove_by_name_ns+0x3b/0x80 [12301.899080] bus_remove_driver+0x92/0xa0 [12301.899085] acpi_video_unregister+0x24/0x40 [12301.899127] i915_driver_unload+0x42/0x130 [i915] [12301.899160] i915_pci_remove+0x19/0x30 [i915] [12301.899169] pci_device_remove+0x36/0xb0 [12301.899176] device_release_driver_internal+0x185/0x240 [12301.899183] unbind_store+0xaf/0x180 [12301.899189] kernfs_fop_write+0x104/0x190 [12301.899195] __vfs_write+0x31/0x180 [12301.899203] ? rcu_read_lock_sched_held+0x6f/0x80 [12301.899209] ? rcu_sync_lockdep_assert+0x29/0x50 [12301.899216] ? __sb_start_write+0x13c/0x1a0 [12301.899221] ? vfs_write+0x17f/0x1b0 [12301.899227] vfs_write+0xb9/0x1b0 [12301.899233] ksys_write+0x50/0xc0 [12301.899239] do_syscall_64+0x4b/0x180 [12301.899247] entry_SYSCALL_64_after_hwframe+0x49/0xbe [12301.899253] RIP: 0033:0x7f452ac7f7a4 [12301.899259] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 aa f0 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83 [12301.899273] RSP: 002b:00007ffceafa6918 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [12301.899282] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f452ac7f7a4 [12301.899288] RDX: 000000000000000d RSI: 00005612a1abf7c0 RDI: 0000000000000001 [12301.899295] RBP: 00005612a1abf7c0 R08: 000000000000000a R09: 00005612a1c46730 [12301.899301] R10: 000000000000000a R11: 0000000000000246 R12: 000000000000000d [12301.899308] R13: 0000000000000001 R14: 00007f452af4a740 R15: 000000000000000d Looking around I've noticed that usb and i2c already handle similar recursion problems, where a sysfs file can unbind the same type of sysfs somewhere else in the hierarchy. Relevant commits are: commit 356c05d58af05d582e634b54b40050c73609617b Author: Alan Stern <stern@rowland.harvard.edu> Date: Mon May 14 13:30:03 2012 -0400 sysfs: get rid of some lockdep false positives commit e9b526fe704812364bca07edd15eadeba163ebfb Author: Alexander Sverdlin <alexander.sverdlin@nsn.com> Date: Fri May 17 14:56:35 2013 +0200 i2c: suppress lockdep warning on delete_device Implement the same trick for driver bind/unbind. v2: Put the macro into bus.c (Greg). Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Ramalingam C <ramalingam.c@intel.com> Cc: Arend van Spriel <aspriel@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: Vivek Gautam <vivek.gautam@codeaurora.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-21 18:18:48 +0000