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path: root/drivers/base/bus.c
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2017-08-31driver core: bus: Fix a potential double freeChristophe JAILLET
The .release function of driver_ktype is 'driver_release()'. This function frees the container_of this kobject. So, this memory must not be freed explicitly in the error handling path of 'bus_add_driver()'. Otherwise a double free will occur. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-12driver-core: remove struct bus_type.dev_attrsGreg Kroah-Hartman
Now that all in-kernel users of bus_type.dev_attrs have been converted to use dev_groups instead, the dev_attrs field, and logic surrounding it, can be removed. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25kobject: support passing in variables for synthetic ueventsPeter Rajnoha
This patch makes it possible to pass additional arguments in addition to uevent action name when writing /sys/.../uevent attribute. These additional arguments are then inserted into generated synthetic uevent as additional environment variables. Before, we were not able to pass any additional uevent environment variables for synthetic uevents. This made it hard to identify such uevents properly in userspace to make proper distinction between genuine uevents originating from kernel and synthetic uevents triggered from userspace. Also, it was not possible to pass any additional information which would make it possible to optimize and change the way the synthetic uevents are processed back in userspace based on the originating environment of the triggering action in userspace. With the extra additional variables, we are able to pass through this extra information needed and also it makes it possible to synchronize with such synthetic uevents as they can be clearly identified back in userspace. The format for writing the uevent attribute is following: ACTION [UUID [KEY=VALUE ...] There's no change in how "ACTION" is recognized - it stays the same ("add", "change", "remove"). The "ACTION" is the only argument required to generate synthetic uevent, the rest of arguments, that this patch adds support for, are optional. The "UUID" is considered as transaction identifier so it's possible to use the same UUID value for one or more synthetic uevents in which case we logically group these uevents together for any userspace listeners. The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" format where "x" is a hex digit. The value appears in uevent as "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable. The "KEY=VALUE" pairs can contain alphanumeric characters only. It's possible to define zero or more more pairs - each pair is then delimited by a space character " ". Each pair appears in synthetic uevents as "SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains "SYNTH_ARG_" prefix to avoid possible collisions with existing variables. To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID" part for the synthetic uevent first. If "UUID" is not passed in, the generated synthetic uevent gains "SYNTH_UUID=0" environment variable automatically so it's possible to identify this situation in userspace when reading generated uevent and so we can still make a difference between genuine and synthetic uevents. Signed-off-by: Peter Rajnoha <prajnoha@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-09driver core: bus: use to_subsys_private and to_device_private_busGeliang Tang
Use to_subsys_private() and to_device_private_bus() instead of open-coding. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-09driver core: bus: use list_for_each_entry*Geliang Tang
Use list_for_each_entry*() instead of list_for_each*() to simplify the code. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20driver-core: add asynchronous probing support for driversDmitry Torokhov
Some devices take a long time when initializing, and not all drivers are suited to initialize their devices when they are open. For example, input drivers need to interrogate their devices in order to publish device's capabilities before userspace will open them. When such drivers are compiled into kernel they may stall entire kernel initialization. This change allows drivers request for their probe functions to be called asynchronously during driver and device registration (manual binding is still synchronous). Because async_schedule is used to perform asynchronous calls module loading will still wait for the probing to complete. Note that the end goal is to make the probing asynchronous by default, so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us to speed up boot process while we validating and fixing the rest of the drivers and preparing userspace. This change is based on earlier patch by "Luis R. Rodriguez" <mcgrof@suse.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25driver core: bus: Goto appropriate labels on failure in bus_add_deviceJunjie Mao
It is not necessary to call device_remove_groups() when device_add_groups() fails. The group added by device_add_groups() should be removed if sysfs_create_link() fails. Fixes: fa6fdb33b486 ("driver core: bus_type: add dev_groups") Signed-off-by: Junjie Mao <junjie_mao@yeah.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07driver core: Fix unbalanced device reference in drivers_probeAlex Williamson
bus_find_device_by_name() acquires a device reference which is never released. This results in an object leak, which on older kernels results in failure to release all resources of PCI devices. libvirt uses drivers_probe to re-attach devices to the host after assignment and is therefore a common trigger for this leak. Example: # cd /sys/bus/pci/ # dmesg -C # echo 1 > devices/0000\:01\:00.0/sriov_numvfs # echo 0 > devices/0000\:01\:00.0/sriov_numvfs # dmesg | grep 01:10 pci 0000:01:10.0: [8086:10ca] type 00 class 0x020000 kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_add_internal: parent: '0000:00:01.0', set: 'devices' kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_uevent_env kobject: '0000:01:10.0' (ffff8801d79cd0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0' kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_uevent_env kobject: '0000:01:10.0' (ffff8801d79cd0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0' kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_uevent_env kobject: '0000:01:10.0' (ffff8801d79cd0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0' kobject: '0000:01:10.0' (ffff8801d79cd0a8): kobject_cleanup, parent (null) kobject: '0000:01:10.0' (ffff8801d79cd0a8): calling ktype release kobject: '0000:01:10.0': free name [kobject freed as expected] # dmesg -C # echo 1 > devices/0000\:01\:00.0/sriov_numvfs # echo 0000:01:10.0 > drivers_probe # echo 0 > devices/0000\:01\:00.0/sriov_numvfs # dmesg | grep 01:10 pci 0000:01:10.0: [8086:10ca] type 00 class 0x020000 kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_add_internal: parent: '0000:00:01.0', set: 'devices' kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_uevent_env kobject: '0000:01:10.0' (ffff8801d79ce0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0' kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_uevent_env kobject: '0000:01:10.0' (ffff8801d79ce0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0' kobject: '0000:01:10.0' (ffff8801d79ce0a8): kobject_uevent_env kobject: '0000:01:10.0' (ffff8801d79ce0a8): fill_kobj_path: path = '/devices/pci0000:00/0000:00:01.0/0000:01:10.0' [no free] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-20Merge branch 'master' into for-nextJiri Kosina
2014-02-19treewide: Fix typo in Documentation/DocBookMasanari Iida
This patch fix spelling typo in Documentation/DocBook. It is because .html and .xml files are generated by make htmldocs, I have to fix a typo within the source files. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-01-08driver-core: Fix use-after-free triggered by bus_unregister()Bart Van Assche
Avoid that bus_unregister() triggers a use-after-free with CONFIG_DEBUG_KOBJECT_RELEASE=y. This patch avoids that the following sequence triggers a kernel crash with memory poisoning enabled: * bus_register() * driver_register() * driver_unregister() * bus_unregister() The above sequence causes the bus private data to be freed from inside the bus_unregister() call although it is not guaranteed in that function that the reference count on the bus private data has dropped to zero. As an example, with CONFIG_DEBUG_KOBJECT_RELEASE=y the ${bus}/drivers kobject is still holding a reference on bus->p->subsys.kobj via its parent pointer at the time the bus private data is freed. Fix this by deferring freeing the bus private data until the last kobject_put() call on bus->p->subsys.kobj. The kernel oops triggered by the above sequence and with memory poisoning enabled and that is fixed by this patch is as follows: general protection fault: 0000 [#1] PREEMPT SMP CPU: 3 PID: 2711 Comm: kworker/3:32 Tainted: G W O 3.13.0-rc4-debug+ #1 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: events kobject_delayed_cleanup task: ffff880037f866d0 ti: ffff88003b638000 task.ti: ffff88003b638000 Call Trace: [<ffffffff81263105>] ? kobject_get_path+0x25/0x100 [<ffffffff81264354>] kobject_uevent_env+0x134/0x600 [<ffffffff8126482b>] kobject_uevent+0xb/0x10 [<ffffffff81262fa2>] kobject_delayed_cleanup+0xc2/0x1b0 [<ffffffff8106c047>] process_one_work+0x217/0x700 [<ffffffff8106bfdb>] ? process_one_work+0x1ab/0x700 [<ffffffff8106c64b>] worker_thread+0x11b/0x3a0 [<ffffffff8106c530>] ? process_one_work+0x700/0x700 [<ffffffff81074b70>] kthread+0xf0/0x110 [<ffffffff81074a80>] ? insert_kthread_work+0x80/0x80 [<ffffffff815673bc>] ret_from_fork+0x7c/0xb0 [<ffffffff81074a80>] ? insert_kthread_work+0x80/0x80 Code: 89 f8 48 89 e5 f6 82 c0 27 63 81 20 74 15 0f 1f 44 00 00 48 83 c0 01 0f b6 10 f6 82 c0 27 63 81 20 75 f0 5d c3 66 0f 1f 44 00 00 <80> 3f 00 55 48 89 e5 74 15 48 89 f8 0f 1f 40 00 48 83 c0 01 80 RIP [<ffffffff81267ed0>] strlen+0x0/0x30 RSP <ffff88003b639c70> ---[ end trace 210f883ef80376aa ]--- Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-28driver-core: remove struct bus_type.drv_attrsGreg Kroah-Hartman
Now that all in-kernel users of bus_type.drv_attrs have been converted to use drv_groups instead, the drv_attrs field, and logic surrounding it, can be removed. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-28driver-core: remove struct bus_type.bus_attrsGreg Kroah-Hartman
Now that all in-kernel users of bus_type.bus_attrs have been converted to use bus_groups instead, the bus_attrs field, and logic surrounding it, can be removed. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27driver core: add #include <linux/sysfs.h> to core files.Greg Kroah-Hartman
This is needed to fix the build on sh systems. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-23driver core: bus: use DRIVER_ATTR_WO()Greg Kroah-Hartman
There are two bus attributes that can better be defined using DRIVER_ATTR_WO(), so convert them to the new macro, making it easier to audit attribute permissions. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-22sysfs.h: remove attr_name() macroGreg Kroah-Hartman
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>
2013-08-21sysfs: add sysfs_create/remove_groups()Greg Kroah-Hartman
These functions are being open-coded in 3 different places in the driver core, and other driver subsystems will want to start doing this as well, so move it to the sysfs core to keep it all in one place, where we know it is written properly. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12driver core: bus_type: add bus_groupsGreg Kroah-Hartman
attribute groups are much more flexible than just a list of attributes, due to their support for visibility of the attributes, and binary attributes. Add bus_groups to struct bus_type which should be used instead of bus_attrs. bus_attrs will be removed from the structure soon. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12driver core: bus_type: add drv_groupsGreg Kroah-Hartman
attribute groups are much more flexible than just a list of attributes, due to their support for visibility of the attributes, and binary attributes. Add drv_groups to struct bus_type which should be used instead of drv_attrs. drv_attrs will be removed from the structure soon. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12driver core: bus_type: add dev_groupsGreg Kroah-Hartman
attribute groups are much more flexible than just a list of attributes, due to their support for visibility of the attributes, and binary attributes. Add dev_groups to struct bus_type which should be used instead of dev_attrs. dev_attrs will be removed from the structure soon. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-21driver core: export subsys_virtual_registerGreg Kroah-Hartman
Modules want to call this function, so it needs to be exported. Reported-by: Daniel Mack <zonque@gmail.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-29Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue updates from Tejun Heo: "A lot of activities on workqueue side this time. The changes achieve the followings. - WQ_UNBOUND workqueues - the workqueues which are per-cpu - are updated to be able to interface with multiple backend worker pools. This involved a lot of churning but the end result seems actually neater as unbound workqueues are now a lot closer to per-cpu ones. - The ability to interface with multiple backend worker pools are used to implement unbound workqueues with custom attributes. Currently the supported attributes are the nice level and CPU affinity. It may be expanded to include cgroup association in future. The attributes can be specified either by calling apply_workqueue_attrs() or through /sys/bus/workqueue/WQ_NAME/* if the workqueue in question is exported through sysfs. The backend worker pools are keyed by the actual attributes and shared by any workqueues which share the same attributes. When attributes of a workqueue are changed, the workqueue binds to the worker pool with the specified attributes while leaving the work items which are already executing in its previous worker pools alone. This allows converting custom worker pool implementations which want worker attribute tuning to use workqueues. The writeback pool is already converted in block tree and there are a couple others are likely to follow including btrfs io workers. - WQ_UNBOUND's ability to bind to multiple worker pools is also used to make it NUMA-aware. Because there's no association between work item issuer and the specific worker assigned to execute it, before this change, using unbound workqueue led to unnecessary cross-node bouncing and it couldn't be helped by autonuma as it requires tasks to have implicit node affinity and workers are assigned randomly. After these changes, an unbound workqueue now binds to multiple NUMA-affine worker pools so that queued work items are executed in the same node. This is turned on by default but can be disabled system-wide or for individual workqueues. Crypto was requesting NUMA affinity as encrypting data across different nodes can contribute noticeable overhead and doing it per-cpu was too limiting for certain cases and IO throughput could be bottlenecked by one CPU being fully occupied while others have idle cycles. While the new features required a lot of changes including restructuring locking, it didn't complicate the execution paths much. The unbound workqueue handling is now closer to per-cpu ones and the new features are implemented by simply associating a workqueue with different sets of backend worker pools without changing queue, execution or flush paths. As such, even though the amount of change is very high, I feel relatively safe in that it isn't likely to cause subtle issues with basic correctness of work item execution and handling. If something is wrong, it's likely to show up as being associated with worker pools with the wrong attributes or OOPS while workqueue attributes are being changed or during CPU hotplug. While this creates more backend worker pools, it doesn't add too many more workers unless, of course, there are many workqueues with unique combinations of attributes. Assuming everything else is the same, NUMA awareness costs an extra worker pool per NUMA node with online CPUs. There are also a couple things which are being routed outside the workqueue tree. - block tree pulled in workqueue for-3.10 so that writeback worker pool can be converted to unbound workqueue with sysfs control exposed. This simplifies the code, makes writeback workers NUMA-aware and allows tuning nice level and CPU affinity via sysfs. - The conversion to workqueue means that there's no 1:1 association between a specific worker, which makes writeback folks unhappy as they want to be able to tell which filesystem caused a problem from backtrace on systems with many filesystems mounted. This is resolved by allowing work items to set debug info string which is printed when the task is dumped. As this change involves unifying implementations of dump_stack() and friends in arch codes, it's being routed through Andrew's -mm tree." * 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (84 commits) workqueue: use kmem_cache_free() instead of kfree() workqueue: avoid false negative WARN_ON() in destroy_workqueue() workqueue: update sysfs interface to reflect NUMA awareness and a kernel param to disable NUMA affinity workqueue: implement NUMA affinity for unbound workqueues workqueue: introduce put_pwq_unlocked() workqueue: introduce numa_pwq_tbl_install() workqueue: use NUMA-aware allocation for pool_workqueues workqueue: break init_and_link_pwq() into two functions and introduce alloc_unbound_pwq() workqueue: map an unbound workqueues to multiple per-node pool_workqueues workqueue: move hot fields of workqueue_struct to the end workqueue: make workqueue->name[] fixed len workqueue: add workqueue->unbound_attrs workqueue: determine NUMA node of workers accourding to the allowed cpumask workqueue: drop 'H' from kworker names of unbound worker pools workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[] workqueue: move pwq_pool_locking outside of get/put_unbound_pool() workqueue: fix memory leak in apply_workqueue_attrs() workqueue: fix unbound workqueue attrs hashing / comparison workqueue: fix race condition in unbound workqueue free path workqueue: remove pwq_lock which is no longer used ...
2013-03-13device: separate all subsys mutexesMichal Hocko
ca22e56d (driver-core: implement 'sysdev' functionality for regular devices and buses) has introduced bus_register macro with a static key to distinguish different subsys mutex classes. This however doesn't work for different subsys which use a common registering function. One example is subsys_system_register (and mce_device and cpu_device). In the end this leads to the following lockdep splat: [ 207.271924] ====================================================== [ 207.271932] [ INFO: possible circular locking dependency detected ] [ 207.271942] 3.9.0-rc1-0.7-default+ #34 Not tainted [ 207.271948] ------------------------------------------------------- [ 207.271957] bash/10493 is trying to acquire lock: [ 207.271963] (subsys mutex){+.+.+.}, at: [<ffffffff8134af27>] bus_remove_device+0x37/0x1c0 [ 207.271987] [ 207.271987] but task is already holding lock: [ 207.271995] (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81046ccf>] cpu_hotplug_begin+0x2f/0x60 [ 207.272012] [ 207.272012] which lock already depends on the new lock. [ 207.272012] [ 207.272023] [ 207.272023] the existing dependency chain (in reverse order) is: [ 207.272033] [ 207.272033] -> #4 (cpu_hotplug.lock){+.+.+.}: [ 207.272044] [<ffffffff810ae329>] lock_acquire+0xe9/0x120 [ 207.272056] [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360 [ 207.272069] [<ffffffff81046ba9>] get_online_cpus+0x29/0x40 [ 207.272082] [<ffffffff81185210>] drain_all_stock+0x30/0x150 [ 207.272094] [<ffffffff811853da>] mem_cgroup_reclaim+0xaa/0xe0 [ 207.272104] [<ffffffff8118775e>] __mem_cgroup_try_charge+0x51e/0xcf0 [ 207.272114] [<ffffffff81188486>] mem_cgroup_charge_common+0x36/0x60 [ 207.272125] [<ffffffff811884da>] mem_cgroup_newpage_charge+0x2a/0x30 [ 207.272135] [<ffffffff81150531>] do_wp_page+0x231/0x830 [ 207.272147] [<ffffffff8115151e>] handle_pte_fault+0x19e/0x8d0 [ 207.272157] [<ffffffff81151da8>] handle_mm_fault+0x158/0x1e0 [ 207.272166] [<ffffffff814b6153>] do_page_fault+0x2a3/0x4e0 [ 207.272178] [<ffffffff814b2578>] page_fault+0x28/0x30 [ 207.272189] [ 207.272189] -> #3 (&mm->mmap_sem){++++++}: [ 207.272199] [<ffffffff810ae329>] lock_acquire+0xe9/0x120 [ 207.272208] [<ffffffff8114c5ad>] might_fault+0x6d/0x90 [ 207.272218] [<ffffffff811a11e3>] filldir64+0xb3/0x120 [ 207.272229] [<ffffffffa013fc19>] call_filldir+0x89/0x130 [ext3] [ 207.272248] [<ffffffffa0140377>] ext3_readdir+0x6b7/0x7e0 [ext3] [ 207.272263] [<ffffffff811a1519>] vfs_readdir+0xa9/0xc0 [ 207.272273] [<ffffffff811a15cb>] sys_getdents64+0x9b/0x110 [ 207.272284] [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b [ 207.272296] [ 207.272296] -> #2 (&type->i_mutex_dir_key#3){+.+.+.}: [ 207.272309] [<ffffffff810ae329>] lock_acquire+0xe9/0x120 [ 207.272319] [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360 [ 207.272329] [<ffffffff8119c254>] link_path_walk+0x6f4/0x9a0 [ 207.272339] [<ffffffff8119e7fa>] path_openat+0xba/0x470 [ 207.272349] [<ffffffff8119ecf8>] do_filp_open+0x48/0xa0 [ 207.272358] [<ffffffff8118d81c>] file_open_name+0xdc/0x110 [ 207.272369] [<ffffffff8118d885>] filp_open+0x35/0x40 [ 207.272378] [<ffffffff8135c76e>] _request_firmware+0x52e/0xb20 [ 207.272389] [<ffffffff8135cdd6>] request_firmware+0x16/0x20 [ 207.272399] [<ffffffffa03bdb91>] request_microcode_fw+0x61/0xd0 [microcode] [ 207.272416] [<ffffffffa03bd554>] microcode_init_cpu+0x104/0x150 [microcode] [ 207.272431] [<ffffffffa03bd61c>] mc_device_add+0x7c/0xb0 [microcode] [ 207.272444] [<ffffffff8134a419>] subsys_interface_register+0xc9/0x100 [ 207.272457] [<ffffffffa04fc0f4>] 0xffffffffa04fc0f4 [ 207.272472] [<ffffffff81000202>] do_one_initcall+0x42/0x180 [ 207.272485] [<ffffffff810bbeff>] load_module+0x19df/0x1b70 [ 207.272499] [<ffffffff810bc376>] sys_init_module+0xe6/0x130 [ 207.272511] [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b [ 207.272523] [ 207.272523] -> #1 (umhelper_sem){++++.+}: [ 207.272537] [<ffffffff810ae329>] lock_acquire+0xe9/0x120 [ 207.272548] [<ffffffff814ae9c4>] down_read+0x34/0x50 [ 207.272559] [<ffffffff81062bff>] usermodehelper_read_trylock+0x4f/0x100 [ 207.272575] [<ffffffff8135c7dd>] _request_firmware+0x59d/0xb20 [ 207.272587] [<ffffffff8135cdd6>] request_firmware+0x16/0x20 [ 207.272599] [<ffffffffa03bdb91>] request_microcode_fw+0x61/0xd0 [microcode] [ 207.272613] [<ffffffffa03bd554>] microcode_init_cpu+0x104/0x150 [microcode] [ 207.272627] [<ffffffffa03bd61c>] mc_device_add+0x7c/0xb0 [microcode] [ 207.272641] [<ffffffff8134a419>] subsys_interface_register+0xc9/0x100 [ 207.272654] [<ffffffffa04fc0f4>] 0xffffffffa04fc0f4 [ 207.272666] [<ffffffff81000202>] do_one_initcall+0x42/0x180 [ 207.272678] [<ffffffff810bbeff>] load_module+0x19df/0x1b70 [ 207.272690] [<ffffffff810bc376>] sys_init_module+0xe6/0x130 [ 207.272702] [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b [ 207.272715] [ 207.272715] -> #0 (subsys mutex){+.+.+.}: [ 207.272729] [<ffffffff810ae002>] __lock_acquire+0x13b2/0x15f0 [ 207.272740] [<ffffffff810ae329>] lock_acquire+0xe9/0x120 [ 207.272751] [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360 [ 207.272763] [<ffffffff8134af27>] bus_remove_device+0x37/0x1c0 [ 207.272775] [<ffffffff81349114>] device_del+0x134/0x1f0 [ 207.272786] [<ffffffff813491f2>] device_unregister+0x22/0x60 [ 207.272798] [<ffffffff814a24ea>] mce_cpu_callback+0x15e/0x1ad [ 207.272812] [<ffffffff814b6402>] notifier_call_chain+0x72/0x130 [ 207.272824] [<ffffffff81073d6e>] __raw_notifier_call_chain+0xe/0x10 [ 207.272839] [<ffffffff81498f76>] _cpu_down+0x1d6/0x350 [ 207.272851] [<ffffffff81499130>] cpu_down+0x40/0x60 [ 207.272862] [<ffffffff8149cc55>] store_online+0x75/0xe0 [ 207.272874] [<ffffffff813474a0>] dev_attr_store+0x20/0x30 [ 207.272886] [<ffffffff812090d9>] sysfs_write_file+0xd9/0x150 [ 207.272900] [<ffffffff8118e10b>] vfs_write+0xcb/0x130 [ 207.272911] [<ffffffff8118e924>] sys_write+0x64/0xa0 [ 207.272923] [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b [ 207.272936] [ 207.272936] other info that might help us debug this: [ 207.272936] [ 207.272952] Chain exists of: [ 207.272952] subsys mutex --> &mm->mmap_sem --> cpu_hotplug.lock [ 207.272952] [ 207.272973] Possible unsafe locking scenario: [ 207.272973] [ 207.272984] CPU0 CPU1 [ 207.272992] ---- ---- [ 207.273000] lock(cpu_hotplug.lock); [ 207.273009] lock(&mm->mmap_sem); [ 207.273020] lock(cpu_hotplug.lock); [ 207.273031] lock(subsys mutex); [ 207.273040] [ 207.273040] *** DEADLOCK *** [ 207.273040] [ 207.273055] 5 locks held by bash/10493: [ 207.273062] #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff81209049>] sysfs_write_file+0x49/0x150 [ 207.273080] #1: (s_active#150){.+.+.+}, at: [<ffffffff812090c2>] sysfs_write_file+0xc2/0x150 [ 207.273099] #2: (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81027557>] cpu_hotplug_driver_lock+0x17/0x20 [ 207.273121] #3: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8149911c>] cpu_down+0x2c/0x60 [ 207.273140] #4: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81046ccf>] cpu_hotplug_begin+0x2f/0x60 [ 207.273158] [ 207.273158] stack backtrace: [ 207.273170] Pid: 10493, comm: bash Not tainted 3.9.0-rc1-0.7-default+ #34 [ 207.273180] Call Trace: [ 207.273192] [<ffffffff810ab373>] print_circular_bug+0x223/0x310 [ 207.273204] [<ffffffff810ae002>] __lock_acquire+0x13b2/0x15f0 [ 207.273216] [<ffffffff812086b0>] ? sysfs_hash_and_remove+0x60/0xc0 [ 207.273227] [<ffffffff810ae329>] lock_acquire+0xe9/0x120 [ 207.273239] [<ffffffff8134af27>] ? bus_remove_device+0x37/0x1c0 [ 207.273251] [<ffffffff814ad807>] mutex_lock_nested+0x37/0x360 [ 207.273263] [<ffffffff8134af27>] ? bus_remove_device+0x37/0x1c0 [ 207.273274] [<ffffffff812086b0>] ? sysfs_hash_and_remove+0x60/0xc0 [ 207.273286] [<ffffffff8134af27>] bus_remove_device+0x37/0x1c0 [ 207.273298] [<ffffffff81349114>] device_del+0x134/0x1f0 [ 207.273309] [<ffffffff813491f2>] device_unregister+0x22/0x60 [ 207.273321] [<ffffffff814a24ea>] mce_cpu_callback+0x15e/0x1ad [ 207.273332] [<ffffffff814b6402>] notifier_call_chain+0x72/0x130 [ 207.273344] [<ffffffff81073d6e>] __raw_notifier_call_chain+0xe/0x10 [ 207.273356] [<ffffffff81498f76>] _cpu_down+0x1d6/0x350 [ 207.273368] [<ffffffff81027557>] ? cpu_hotplug_driver_lock+0x17/0x20 [ 207.273380] [<ffffffff81499130>] cpu_down+0x40/0x60 [ 207.273391] [<ffffffff8149cc55>] store_online+0x75/0xe0 [ 207.273402] [<ffffffff813474a0>] dev_attr_store+0x20/0x30 [ 207.273413] [<ffffffff812090d9>] sysfs_write_file+0xd9/0x150 [ 207.273425] [<ffffffff8118e10b>] vfs_write+0xcb/0x130 [ 207.273436] [<ffffffff8118e924>] sys_write+0x64/0xa0 [ 207.273447] [<ffffffff814bb599>] system_call_fastpath+0x16/0x1b Which reports a false possitive deadlock because it sees: 1) load_module -> subsys_interface_register -> mc_deveice_add (*) -> subsys->p->mutex -> link_path_walk -> lookup_slow -> i_mutex 2) sys_write -> _cpu_down -> cpu_hotplug_begin -> cpu_hotplug.lock -> mce_cpu_callback -> mce_device_remove(**) -> device_unregister -> bus_remove_device -> subsys mutex 3) vfs_readdir -> i_mutex -> filldir64 -> might_fault -> might_lock_read(mmap_sem) -> page_fault -> mmap_sem -> drain_all_stock -> cpu_hotplug.lock but 1) takes cpu_subsys subsys (*) but 2) takes mce_device subsys (**) so the deadlock is not possible AFAICS. The fix is quite simple. We can pull the key inside bus_type structure because they are defined per device so the pointer will be unique as well. bus_register doesn't need to be a macro anymore so change it to the inline. We could get rid of __bus_register as there is no other caller but maybe somebody will want to use a different key so keep it around for now. Reported-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-12driver/base: implement subsys_virtual_register()Tejun Heo
Kay tells me the most appropriate place to expose workqueues to userland would be /sys/devices/virtual/workqueues/WQ_NAME which is symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking a way to do that outside of driver core as virtual_device_parent() isn't exported and there's no inteface to conveniently create a virtual subsystem. This patch implements subsys_virtual_register() by factoring out subsys_register() from subsys_system_register() and using it with virtual_device_parent() as the origin directory. It's identical to subsys_system_register() other than the origin directory but we aren't gonna restrict the device names which should be used under it. This will be used to expose workqueue attributes to userland. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kay Sievers <kay.sievers@vrfy.org>
2013-02-03Driver core: treat unregistered bus_types as having no devicesBjorn Helgaas
A bus_type has a list of devices (klist_devices), but the list and the subsys_private structure that contains it are not initialized until the bus_type is registered with bus_register(). The panic/reboot path has fixups that look up devices in pci_bus_type. If we panic before registering pci_bus_type, the bus_type exists but the list does not, so mach_reboot_fixups() trips over a null pointer and panics again: mach_reboot_fixups pci_get_device .. bus_find_device(&pci_bus_type, ...) bus->p is NULL Joonsoo reported a problem when panicking before PCI was initialized. I think this patch should be sufficient to replace the patch he posted here: https://lkml.org/lkml/2012/12/28/75 ("[PATCH] x86, reboot: skip reboot_fixups in early boot phase") Reported-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17driver core: fix possible missing of device probeMing Lei
Inside bus_add_driver(), one device might be added(device_add()) into the bus or probed which is triggered by deferred probe just after completing of driver_attach() and before 'klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers)', so the device won't be probed by this driver. This patch moves the below line 'klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers)' before driver_attach() inside bus_add_driver() to fix the problem. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28driver core: remove CONFIG_HOTPLUG ifdefsBill Pemberton
Remove conditional code based on CONFIG_HOTPLUG being false. It's always on now in preparation of it going away as an option. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16driver core: move uevent call to driver_registerSebastian Ott
Device driver attribute groups are created after userspace is notified via an add event. Fix this by moving the kobject_uevent call to driver_register after the attribute groups are added. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-19Revert "driver core: check start node in klist_iter_init_node"Greg Kroah-Hartman
This reverts commit a15d49fd3094cff90e5410ca454a870e0a722fe1 as that patch broke the build. Cc: Hannes Reinecke <hare@suse.de> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-18driver core: check start node in klist_iter_init_nodeHannes Reinecke
klist_iter_init_node() takes a node as a start argument. However, this node might not be valid anymore. This patch updates the klist_iter_init_node() and dependent functions to return an error if so. All calling functions have been audited to check for a return code here. Signed-off-by: Hannes Reinecke <hare@suse.de> Cc: Greg Kroah-Hartmann <gregkh@linuxfoundation.org> Cc: Kay Sievers <kay@vrfy.org> Cc: Stable Kernel <stable@kernel.org> Cc: Linux Kernel <linux-kernel@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-18drivers/base/bus.c: local variables should not be exposed globallyH Hartley Sweeten
The variable 'system_kset' is only referenced in this file and should be marked static to prevent it from being exposed globally. This quiets the sparse waring: warning: symbol 'system_kset' was not declared. Should it be static? Also, remove the comment since drivers/base/sys.c has now been deleted. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-02Merge 3.3-rc2 into the driver-core-next branch.Greg Kroah-Hartman
This was done to resolve a merge and build problem with the drivers/acpi/processor_driver.c file. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-24driver-core: Fix possible null reference in subsys_interface_unregisterJonghwan Choi
Check if the sif is not NULL before de-referencing it Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2012-01-23kernel-doc: fix new warnings in driver-coreRandy Dunlap
Fix new kernel-doc warnings: Warning(drivers/base/bus.c:925): No description found for parameter 'key' Warning(drivers/base/bus.c:1241): No description found for parameter 'subsys' Warning(drivers/base/bus.c:1241): No description found for parameter 'groups' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-14driver-core: implement 'sysdev' functionality for regular devices and busesKay Sievers
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>
2011-01-13Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) Documentation/trace/events.txt: Remove obsolete sched_signal_send. writeback: fix global_dirty_limits comment runtime -> real-time ppc: fix comment typo singal -> signal drivers: fix comment typo diable -> disable. m68k: fix comment typo diable -> disable. wireless: comment typo fix diable -> disable. media: comment typo fix diable -> disable. remove doc for obsolete dynamic-printk kernel-parameter remove extraneous 'is' from Documentation/iostats.txt Fix spelling milisec -> ms in snd_ps3 module parameter description Fix spelling mistakes in comments Revert conflicting V4L changes i7core_edac: fix typos in comments mm/rmap.c: fix comment sound, ca0106: Fix assignment to 'channel'. hrtimer: fix a typo in comment init/Kconfig: fix typo anon_inodes: fix wrong function name in comment fix comment typos concerning "consistent" poll: fix a typo in comment ... Fix up trivial conflicts in: - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c) - fs/ext4/ext4.h Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2010-11-21Fix "forcably" comment typoRobert P. J. Day
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-17driver-core: merge private parts of class and busKay Sievers
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>
2010-10-22driver core: remove CONFIG_SYSFS_DEPRECATED_V2 but keep it for block devicesKay Sievers
This patch removes the old CONFIG_SYSFS_DEPRECATED_V2 config option, but it keeps the logic around to handle block devices in the old manner as some people like to run new kernel versions on old (pre 2007/2008) distros. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: "James E.J. Bottomley" <James.Bottomley@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Tejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05driver core: fix memory leak on one error path in bus_register()Jike Song
Reported-by: huangweibing@gmail.com Signed-off-by: Jike Song <albcamus@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-07Driver core: create lock/unlock functions for struct deviceGreg Kroah-Hartman
In the future, we are going to be changing the lock type for struct device (once we get the lockdep infrastructure properly worked out) To make that changeover easier, and to possibly burry the lock in a different part of struct device, let's create some functions to lock and unlock a device so that no out-of-core code needs to be changed in the future. This patch creates the device_lock/unlock/trylock() functions, and converts all in-tree users to them. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jean Delvare <khali@linux-fr.org> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <len.brown@intel.com> Cc: Magnus Damm <damm@igel.co.jp> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Alex Chiang <achiang@hp.com> Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Yu Zhao <yu.zhao@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: CHENG Renquan <rqcheng@smu.edu.sg> Cc: Oliver Neukum <oliver@neukum.org> Cc: Frans Pop <elendil@planet.nl> Cc: David Vrabel <david.vrabel@csr.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07Driver core: Constify struct sysfs_ops in struct kobj_typeEmese Revfy
Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: David Teigland <teigland@redhat.com> Acked-by: Matt Domsch <Matt_Domsch@dell.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07kobject: Constify struct kset_uevent_opsEmese Revfy
Constify struct kset_uevent_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-23driver core: Prevent reference to freed memory on error pathPhil Carmody
priv is drv->p. So only free drv->p after we've finished using priv. Found using a static code analysis tool Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-10-30Driver core: allow certain drivers prohibit bind/unbind via sysfsDmitry Torokhov
Platform drivers registered via platform_driver_probe() can be bound to devices only once, upon registration, because discard their probe() routines to save memory. Unbinding the driver through sysfs 'unbind' leaves the device stranded and confuses users so let's not create bind and unbind attributes for such drivers. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Cc: Éric Piel <eric.piel@tremplin-utc.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15Driver core: add new device to bus's list before probingAlan Stern
This patch (as1271) affects when new devices get linked into their bus's list of devices. Currently this happens after probing, and it doesn't happen at all if probing fails. Clearly this is wrong, because at that point quite a few symbolic links have already been created in sysfs. We are committed to adding the device, so it should be linked into the bus's list regardless. In addition, this needs to happen before the uevent announcing the new device gets issued. Otherwise user programs might try to access the device before it has been added to the bus. To fix both these problems, the patch moves the call to klist_add_tail() forward from bus_attach_device() to bus_add_device(). Since bus_attach_device() now does nothing but probe for drivers, it has been renamed to bus_probe_device(). And lastly, the kerneldoc is updated. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-12trivial: fix grammo in bus_for_each_dev() kerneldocAlex Chiang
Signed-off-by: Alex Chiang <achiang@hp.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-05-28Driver Core: do not oops when driver_unregister() is called for unregistered ↵Kay Sievers
drivers We also fix a problem with cleaning up properly when initializing drivers and devices, so checks like this will work successfully. Portions of the patch by Linus and Greg and Ingo. Reported-by: Ozan Çağlayan <ozan@pardus.org.tr> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24driver core: move knode_bus into private structureGreg Kroah-Hartman
Nothing outside of the driver core should ever touch knode_bus, so move it out of the public eye. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>