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2020-07-10kobject: Avoid premature parent object freeing in kobject_cleanup()Heikki Krogerus
If kobject_del() is invoked by kobject_cleanup() to delete the target kobject, it may cause its parent kobject to be freed before invoking the target kobject's ->release() method, which effectively means freeing the parent before dealing with the child entirely. That is confusing at best and it may also lead to functional issues if the callers of kobject_cleanup() are not careful enough about the order in which these calls are made, so avoid the problem by making kobject_cleanup() drop the last reference to the target kobject's parent at the end, after invoking the target kobject's ->release() method. [ rjw: Rewrite the subject and changelog, make kobject_cleanup() drop the parent reference only when __kobject_del() has been called. ] Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: kernel test robot <rong.a.chen@intel.com> Fixes: 7589238a8cf3 ("Revert "software node: Simplify software_node_release() function"") Suggested-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/1908555.IiAGLGrh1Z@kreacher Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-07Merge tag 'driver-core-5.8-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of driver core patches for 5.8-rc1. Not all that huge this release, just a number of small fixes and updates: - software node fixes - kobject now sends KOBJ_REMOVE when it is removed from sysfs, not when it is removed from memory (which could come much later) - device link additions and fixes based on testing on more devices - firmware core cleanups - other minor changes, full details in the shortlog All have been in linux-next for a while with no reported issues" * tag 'driver-core-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits) driver core: Update device link status correctly for SYNC_STATE_ONLY links firmware_loader: change enum fw_opt to u32 software node: implement software_node_unregister() kobject: send KOBJ_REMOVE uevent when the object is removed from sysfs driver core: Remove unnecessary is_fwnode_dev variable in device_add() drivers property: When no children in primary, try secondary driver core: platform: Fix spelling errors in platform.c driver core: Remove check in driver_deferred_probe_force_trigger() of: platform: Batch fwnode parsing when adding all top level devices driver core: fw_devlink: Add support for batching fwnode parsing driver core: Look for waiting consumers only for a fwnode's primary device driver core: Move code to the right part of the file Revert "Revert "driver core: Set fw_devlink to "permissive" behavior by default"" drivers: base: Fix NULL pointer exception in __platform_driver_probe() if a driver developer is foolish firmware_loader: move fw_fallback_config to a private kernel symbol namespace driver core: Add missing '\n' in log messages driver/base/soc: Use kobj_to_dev() API Add documentation on meaning of -EPROBE_DEFER driver core: platform: remove redundant assignment to variable ret debugfs: Use the correct style for SPDX License Identifier ...
2020-05-25kobject: send KOBJ_REMOVE uevent when the object is removed from sysfsGreg Kroah-Hartman
It is possible for a KOBJ_REMOVE uevent to be sent to userspace way after the files are actually gone from sysfs, due to how reference counting for kobjects work. This should not be a problem, but it would be good to properly send the information when things are going away, not at some later point in time in the future. Before this move, if a kobject's parent was torn down before the child, when the call to kobject_uevent() happened, the parent walk to try to reconstruct the full path of the kobject could be a total mess and cause crashes. It's not good to try to tear down a kobject tree from top down, but let's at least try to not to crash if a user does so. Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20200524153041.2361-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-20docs: filesystems: fix renamed referencesMauro Carvalho Chehab
Some filesystem references got broken by a previous patch series I submitted. Address those. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: David Sterba <dsterba@suse.com> # fs/affs/Kconfig Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-19lib : kobject: fix refcount imblance on kobject_renameLin Yi
the kobj refcount increased by kobject_get should be released before error return, otherwise lead to a memory leak. Signed-off-by: Lin Yi <teroincn@163.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-03kobject: clean up the kobject add documentation a bit moreGreg Kroah-Hartman
Commit 1fd7c3b438a2 ("kobject: Improve doc clarity kobject_init_and_add()") tried to provide more clarity, but the reference to kobject_del() was incorrect. Fix that up by removing that line, and hopefully be more explicit as to exactly what needs to happen here once you register a kobject with the kobject core. Acked-by: Tobin C. Harding <tobin@kernel.org> Fixes: 1fd7c3b438a2 ("kobject: Improve doc clarity kobject_init_and_add()") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02kobject: Fix kernel-doc comment first lineTobin C. Harding
kernel-doc comments have a prescribed format. This includes parenthesis on the function name. To be _particularly_ correct we should also capitalise the brief description and terminate it with a period. In preparation for adding/updating kernel-doc function comments clean up the ones currently present. Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02kobject: Remove docstring reference to ksetTobin C. Harding
Currently the docstring for kobject_get_path() mentions 'kset'. The kset is not used in the function callchain starting from this function. Remove docstring reference to kset from the function kobject_get_path(). Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-01kobject: fix dereference before null check on kobjColin Ian King
The kobj pointer is being null-checked so potentially it could be null, however, the ktype declaration before the null check is dereferencing kobj hence we have a potential null pointer deference. Fix this by moving the assignment of ktype after kobj has been null checked. Addresses-Coverity: ("Dereference before null check") Fixes: aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-28kobject: Improve doc clarity kobject_init_and_add()Tobin C. Harding
Function kobject_init_and_add() is currently misused in a number of places in the kernel. On error return kobject_put() must be called but is at times not. Make the function documentation more explicit about calling kobject_put() in the error path. Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-28kobject: Improve docs for kobject_add/delTobin C. Harding
There is currently some confusion on how to wind back kobject_init_and_add() during the error paths in code that uses this function. Add documentation to kobject_add() and kobject_del() to help clarify the usage. Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25kobject: Add support for default attribute groups to kobj_typeKimberly Brown
kobj_type currently uses a list of individual attributes to store default attributes. Attribute groups are more flexible than a list of attributes because groups provide support for attribute visibility. So, add support for default attribute groups to kobj_type. In future patches, the existing uses of kobj_type’s attribute list will be converted to attribute groups. When that is complete, kobj_type’s attribute list, “default_attrs”, will be removed. Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-22kobject: make kset_get_ownership() 'static'Eric Biggers
kset_get_ownership() is only used in lib/kobject.c, so make it 'static'. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-06kref/kobject: Improve documentationEzequiel Garcia
The current kref and kobject documentation may be insufficient to understand these common pitfalls regarding object lifetime and object releasing. Add a bit more documentation and improve the warnings seen by the user, pointing to the right piece of documentation. Also, it's important to understand that making fun of people publicly is not at all helpful, doesn't provide any value, and it's not a healthy way of encouraging developers to do better. "Mocking mercilessly" will, if anything, make developers feel bad and go away. This kind of behavior should not be encouraged or justified. Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com> Signed-off-by: Matthias Brugger <mbrugger@suse.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-18Merge tag 'driver-core-4.19-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported" * tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) base: core: Remove WARN_ON from link dependencies check drivers/base: stop new probing during shutdown drivers: core: Remove glue dirs from sysfs earlier driver core: remove unnecessary function extern declare sysfs.h: fix non-kernel-doc comment PM / Domains: Stop deferring probe at the end of initcall iommu: Remove IOMMU_OF_DECLARE iommu: Stop deferring probe at end of initcalls pinctrl: Support stopping deferred probe after initcalls dt-bindings: pinctrl: add a 'pinctrl-use-default' property driver core: allow stopping deferred probe after init driver core: add a debugfs entry to show deferred devices sysfs: Fix internal_create_group() for named group updates base: fix order of OF initialization linux/device.h: fix kernel-doc notation warning Documentation: update firmware loader fallback reference kobject: Replace strncpy with memcpy drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number kernfs: Replace strncpy with memcpy device: Add #define dev_fmt similar to #define pr_fmt ...
2018-07-20kobject: kset_create_and_add() - fetch ownership info from parentDmitry Torokhov
This change implements get_ownership() for ksets created with kset_create_and_add() call by fetching ownership data from parent kobject. This is done mostly for benefit of "queues" attribute of net devices so that corresponding directory belongs to container's root instead of global root for network devices in a container. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20sysfs, kobject: allow creating kobject belonging to arbitrary usersDmitry Torokhov
Normally kobjects and their sysfs representation belong to global root, however it is not necessarily the case for objects in separate namespaces. For example, objects in separate network namespace logically belong to the container's root and not global root. This change lays groundwork for allowing network namespace objects ownership to be transferred to container's root user by defining get_ownership() callback in ktype structure and using it in sysfs code to retrieve desired uid/gid when creating sysfs objects for given kobject. Co-Developed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07kobject: Replace strncpy with memcpyGuenter Roeck
gcc 8.1.0 complains: lib/kobject.c:128:3: warning: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length [-Wstringop-truncation] lib/kobject.c: In function 'kobject_get_path': lib/kobject.c:125:13: note: length computed here Using strncpy() is indeed less than perfect since the length of data to be copied has already been determined with strlen(). Replace strncpy() with memcpy() to address the warning and optimize the code a little. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-23kobject: don't use WARN for registration failuresDmitry Vyukov
This WARNING proved to be noisy. The function still returns an error and callers should handle it. That's how most of kernel code works. Downgrade the WARNING to pr_err() and leave WARNINGs for kernel bugs. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: syzbot+209c0f67f99fec8eb14b@syzkaller.appspotmail.com Reported-by: syzbot+7fb6d9525a4528104e05@syzkaller.appspotmail.com Reported-by: syzbot+2e63711063e2d8f9ea27@syzkaller.appspotmail.com Reported-by: syzbot+de73361ee4971b6e6f75@syzkaller.appspotmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-15lib/kobject: Join string literals backAndy Shevchenko
There is no need to split string literals. Moreover, it would be simpler to grep for an actual code line, when debugging, by using almost any part of the string literal in question. While here, replace printk(LEVEL) by pr_lvl() macros. No functional change intended. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-01Merge tag 'driver-core-4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of "big" driver core patches for 4.16-rc1. The majority of the work here is in the firmware subsystem, with reworks to try to attempt to make the code easier to handle in the long run, but no functional change. There's also some tree-wide sysfs attribute fixups with lots of acks from the various subsystem maintainers, as well as a handful of other normal fixes and changes. And finally, some license cleanups for the driver core and sysfs code. All have been in linux-next for a while with no reported issues" * tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (48 commits) device property: Define type of PROPERTY_ENRTY_*() macros device property: Reuse property_entry_free_data() device property: Move property_entry_free_data() upper firmware: Fix up docs referring to FIRMWARE_IN_KERNEL firmware: Drop FIRMWARE_IN_KERNEL Kconfig option USB: serial: keyspan: Drop firmware Kconfig options sysfs: remove DEBUG defines sysfs: use SPDX identifiers drivers: base: add coredump driver ops sysfs: add attribute specification for /sysfs/devices/.../coredump test_firmware: fix missing unlock on error in config_num_requests_store() test_firmware: make local symbol test_fw_config static sysfs: turn WARN() into pr_warn() firmware: Fix a typo in fallback-mechanisms.rst treewide: Use DEVICE_ATTR_WO treewide: Use DEVICE_ATTR_RO treewide: Use DEVICE_ATTR_RW sysfs.h: Use octal permissions component: add debugfs support bus: simple-pm-bus: convert bool SIMPLE_PM_BUS to tristate ...
2018-01-23kobject: Export kobj_ns_grab_current() and kobj_ns_drop()Bart Van Assche
Make it possible to call these two functions from a kernel module. Note: despite their name, these two functions can be used meaningfully independent of kobjects. A later patch will add calls to these functions from the SRP driver because this patch series modifies the SRP driver such that it can hold a reference to a namespace that can last longer than the lifetime of the process through which the namespace reference was obtained. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-12-07kobject: Remove redundant license textGreg Kroah-Hartman
Now that the SPDX tag is in all kobject 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. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07kobject: add SPDX identifiers to all kobject 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 kobject 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: 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>
2017-03-22kobject: Export kobject_get_unless_zero()Jan Kara
Make the function available for outside use and fortify it against NULL kobject. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-09kobject: export kset_find_obj() for module useGabriel Somlo
Signed-off-by: Gabriel Somlo <somlo@cmu.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-06lib/kobject.c: use kvasprintf_const for formatting ->nameRasmus Villemoes
Sometimes kobject_set_name_vargs is called with a format string conaining no %, or a format string of precisely "%s", where the single vararg happens to point to .rodata. kvasprintf_const detects these cases for us and returns a copy of that pointer instead of duplicating the string, thus saving some run-time memory. Otherwise, it falls back to kvasprintf. We just need to always deallocate ->name using kfree_const. Unfortunately, the dance we need to do to perform the '/' -> '!' sanitization makes the resulting code rather ugly. I instrumented kstrdup_const to provide some statistics on the memory saved, and for me this gave an additional ~14KB after boot (306KB was already saved; this patch bumped that to 320KB). I have KMALLOC_SHIFT_LOW==3, and since 80% of the kvasprintf_const hits were satisfied by an 8-byte allocation, the 14K would roughly be quadrupled when KMALLOC_SHIFT_LOW==5. Whether these numbers are sufficient to justify the ugliness I'll leave to others to decide. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-04kobject: move EXPORT_SYMBOL() macros next to corresponding definitionsGabriel Somlo
Move EXPORT_SYMBOL() macros in kobject.c from the end of the file next to the function definitions to which they belong. Signed-off-by: Gabriel Somlo <somlo@cmu.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-17include, lib: add __printf attributes to several function prototypesNicolas Iooss
Using __printf attributes helps to detect several format string issues at compile time (even though -Wformat-security is currently disabled in Makefile). For example it can detect when formatting a pointer as a number, like the issue fixed in commit a3fa71c40f18 ("wl18xx: show rx_frames_per_rates as an array as it really is"), or when the arguments do not match the format string, c.f. for example commit 5ce1aca81435 ("reiserfs: fix __RASSERT format string"). To prevent similar bugs in the future, add a __printf attribute to every function prototype which needs one in include/linux/ and lib/. These functions were mostly found by using gcc's -Wsuggest-attribute=format flag. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Felipe Balbi <balbi@ti.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30Merge branch 'for-linus-4.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "Outside of our usual batch of fixes, this integrates the subvolume quota updates that Qu Wenruo from Fujitsu has been working on for a few releases now. He gets an extra gold star for making btrfs smaller this time, and fixing a number of quota corners in the process. Dave Sterba tested and integrated Anand Jain's sysfs improvements. Outside of exporting a symbol (ack'd by Greg) these are all internal to btrfs and it's mostly cleanups and fixes. Anand also attached some of our sysfs objects to our internal device management structs instead of an object off the super block. It will make device management easier overall and it's a better fit for how the sysfs files are used. None of the existing sysfs files are moved around. Thanks for all the fixes everyone" * 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (87 commits) btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref() Btrfs: Check if kobject is initialized before put lib: export symbol kobject_move() Btrfs: sysfs: add support to show replacing target in the sysfs Btrfs: free the stale device Btrfs: use received_uuid of parent during send Btrfs: fix use-after-free in btrfs_replay_log btrfs: wait for delayed iputs on no space btrfs: qgroup: Make snapshot accounting work with new extent-oriented qgroup. btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots. btrfs: ulist: Add ulist_del() function. btrfs: qgroup: Cleanup the old ref_node-oriented mechanism. btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism. btrfs: qgroup: Switch to new extent-oriented qgroup mechanism. btrfs: qgroup: Switch rescan to new mechanism. btrfs: qgroup: Add new qgroup calculation function btrfs_qgroup_account_extents(). btrfs: backref: Add special time_seq == (u64)-1 case for btrfs_find_all_roots(). btrfs: qgroup: Add new function to record old_roots. btrfs: qgroup: Record possible quota-related extent for qgroup. btrfs: qgroup: Add function qgroup_update_counters(). ...
2015-06-25lib/kobject.c: use strreplace()Rasmus Villemoes
There's probably not many slashes in the name, but starting over when we see one feels wrong. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-19lib: export symbol kobject_move()Anand Jain
drivers/cpufreq/cpufreq.c is already using this function. And now btrfs needs it as well. Export symbol kobject_move(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David Sterba <dsterba@suse.cz>
2015-03-25kobject: WARN as tip when call kobject_get() to a kobject not initializedEthan Zhao
call kobject_get() to kojbect that is not initalized or released will only leave following like call trace to us: -----------[ cut here ]------------ [ 54.545816] WARNING: CPU: 0 PID: 213 at include/linux/kref.h:47 kobject_get+0x41/0x50() [ 54.642595] Modules linked in: i2c_i801(+) mfd_core shpchp(+) acpi_cpufreq(+) edac_core ioatdma(+) xfs libcrc32c ast syscopyarea ixgbe sysfillrect sysimgblt sr_mod sd_mod drm_kms_helper igb mdio cdrom e1000e ahci dca ttm libahci uas drm i2c_algo_bit ptp megaraid_sas libata usb_storage i2c_core pps_core dm_mirror dm_region_hash dm_log dm_mod [ 55.007264] CPU: 0 PID: 213 Comm: kworker/0:2 Not tainted 3.18.5 [ 55.099970] Hardware name: Oracle Corporation SUN FIRE X4170 M2 SERVER /ASSY,MOTHERBOARD,X4170, BIOS 08120104 05/08/2012 [ 55.239736] Workqueue: kacpi_notify acpi_os_execute_deferred [ 55.308598] 0000000000000000 00000000bd730b61 ffff88046742baf8 ffffffff816b7edb [ 55.398305] 0000000000000000 0000000000000000 ffff88046742bb38 ffffffff81078ae1 [ 55.488040] ffff88046742bbd8 ffff8806706b3000 0000000000000292 0000000000000000 [ 55.577776] Call Trace: [ 55.608228] [<ffffffff816b7edb>] dump_stack+0x46/0x58 [ 55.670895] [<ffffffff81078ae1>] warn_slowpath_common+0x81/0xa0 [ 55.743952] [<ffffffff81078bfa>] warn_slowpath_null+0x1a/0x20 [ 55.814929] [<ffffffff8130d0d1>] kobject_get+0x41/0x50 [ 55.878654] [<ffffffff8153e955>] cpufreq_cpu_get+0x75/0xc0 [ 55.946528] [<ffffffff8153f37e>] cpufreq_update_policy+0x2e/0x1f0 The above issue was casued by a race condition, if there is a WARN in kobject_get() of the kobject is not initialized, that would save us much time to debug it. Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07kobject: fix NULL pointer derefernce in kobj_child_ns_opsPankaj Dubey
We will hit NULL pointer dereference if we call platform_device_register_simple or platform_device_add at very early stage. I have observed following crash when called platform_device_add from "init_irq" hook of machine_desc. This patch fixes this issue and let system handle this case gracefully instead of kernel panic. [0.000000] Unable to handle kernel NULL pointer dereference at virtual address 0000000c [0.000000] pgd = c0004000 [0.000000] [0000000c] *pgd=00000000 [0.000000] Internal error: Oops: 5 [#1] PREEMPT ARM [0.000000] Modules linked in: [0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G W 3.17.0-rc6-00198-ga1603f1-dirty #319 [0.000000] task: c05b23f0 ti: c05a8000 task.ti: c05a8000 [0.000000] PC is at kobject_namespace+0x18/0x58 [0.000000] LR is at kobject_add_internal+0x90/0x2ec [snip] [0.000000] [<c01b1df0>] (kobject_namespace) from [<c01b2338>] (kobject_add_internal+0x90/0x2ec) [0.000000] [<c01b2338>] (kobject_add_internal) from [<c01b2728>] (kobject_add+0x4c/0x98) [0.000000] [<c01b2728>] (kobject_add) from [<c0226274>] (device_add+0xe8/0x51c) [0.000000] [<c0226274>] (device_add) from [<c0229c70>] (platform_device_add+0xb4/0x214) [0.000000] [<c0229c70>] (platform_device_add) from [<c022a338>] (platform_device_register_full+0xb8/0xdc) [0.000000] [<c022a338>] (platform_device_register_full) from [<c0570214>] (exynos_init_irq+0x90/0x9c) [0.000000] [<c0570214>] (exynos_init_irq) from [<c056c18c>] (init_IRQ+0x2c/0x78) [0.000000] [<c056c18c>] (init_IRQ) from [<c0569a54>] (start_kernel+0x22c/0x378) [0.000000] [<c0569a54>] (start_kernel) from [<40008070>] (0x40008070) [0.000000] Code: e590000c e3500000 0a00000e e5903014 (e593300c) Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07sysfs, kobject: add sysfs wrapper for kernfs_enable_ns()Tejun Heo
Currently, kobject is invoking kernfs_enable_ns() directly. This is fine now as sysfs and kernfs are enabled and disabled together. If sysfs is disabled, kernfs_enable_ns() is switched to dummy implementation too and everything is fine; however, kernfs will soon have its own config option CONFIG_KERNFS and !SYSFS && KERNFS will be possible, which can make kobject call into non-dummy kernfs_enable_ns() with NULL kernfs_node pointers leading to an oops. Introduce sysfs_enable_ns() which is a wrapper around kernfs_enable_ns() so that it can be made a noop depending only on CONFIG_SYSFS regardless of the planned CONFIG_KERNFS. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-30Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This is a pretty big pull, and most of these changes have been floating in btrfs-next for a long time. Filipe's properties work is a cool building block for inheriting attributes like compression down on a per inode basis. Jeff Mahoney kicked in code to export filesystem info into sysfs. Otherwise, lots of performance improvements, cleanups and bug fixes. Looks like there are still a few other small pending incrementals, but I wanted to get the bulk of this in first" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits) Btrfs: fix spin_unlock in check_ref_cleanup Btrfs: setup inode location during btrfs_init_inode_locked Btrfs: don't use ram_bytes for uncompressed inline items Btrfs: fix btrfs_search_slot_for_read backwards iteration Btrfs: do not export ulist functions Btrfs: rework ulist with list+rb_tree Btrfs: fix memory leaks on walking backrefs failure Btrfs: fix send file hole detection leading to data corruption Btrfs: add a reschedule point in btrfs_find_all_roots() Btrfs: make send's file extent item search more efficient Btrfs: fix to catch all errors when resolving indirect ref Btrfs: fix protection between walking backrefs and root deletion btrfs: fix warning while merging two adjacent extents Btrfs: fix infinite path build loops in incremental send btrfs: undo sysfs when open_ctree() fails Btrfs: fix snprintf usage by send's gen_unique_name btrfs: fix defrag 32-bit integer overflow btrfs: sysfs: list the NO_HOLES feature btrfs: sysfs: don't show reserved incompat feature btrfs: call permission checks earlier in ioctls and return EPERM ...
2014-01-28kobject: export kobj_sysfs_opsJeff Mahoney
struct kobj_attribute implements the baseline attribute functionality that can be used all over the place. We should export the ops associated with it. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-08kobject: Fix source code comment spellingBart Van Assche
Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-04Revert "kobject: introduce kobj_completion"Greg Kroah-Hartman
This reverts commit eee031649707db3c9920d9498f8d03819b74fc23. Jeff writes: I have no objections to reverting it. There were concerns from Al Viro that it'd be tough to get right by callers and I had assumed it got dropped after that. I had planned on using it in my btrfs sysfs exports patchset but came up with a better way. Cc: Jeff Mahoney <jeffm@suse.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordinglyTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Neil Brown <neilb@suse.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08kobject: fix memory leak in kobject_set_name_vargsMaurizio Lombardi
If the call to kvasprintf fails then the old name of the object will be leaked, this patch fixes the bug by restoring the old name before returning ENOMEM. Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-07kobject: remove kset from sysfs immediately in kset_unregister()Bjorn Helgaas
There's no "unlink from sysfs" interface for ksets, so I think callers of kset_unregister() expect the kset to be removed from sysfs immediately, without waiting for the last reference to be released. This patch makes the sysfs removal happen immediately, so the caller may create a new kset with the same name as soon as kset_unregister() returns. Without this, every caller has to call "kobject_del(&kset->kobj)" first unless it knows it will never create a new kset with the same name. This sometimes shows up on module unload and reload, where the reload fails because it tries to create a kobject with the same name as one from the original load that still exists. CONFIG_DEBUG_KOBJECT_RELEASE=y makes this problem easier to hit. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-07kobject: delay kobject release for random timeBjorn Helgaas
When CONFIG_DEBUG_KOBJECT_RELEASE=y, delay kobject release functions for a random time between 1 and 8 seconds, which effectively changes the order in which they're called. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: introduce kernfs_create_dir[_ns]()Tejun Heo
Introduce kernfs interface to manipulate a directory which takes and returns sysfs_dirents. create_dir() is renamed to kernfs_create_dir_ns() and its argumantes and return value are updated. create_dir() usages are replaced with kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced with kernfs_create_dir(). Dup warnings are handled explicitly by sysfs users of the kernfs interface. sysfs_enable_ns() is renamed to kernfs_enable_ns(). This patch doesn't introduce any behavior changes. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. v3: kernfs_enable_ns() added. v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2" so that this patch removes sysfs_enable_ns(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-27sysfs: drop kobj_ns_type handling, take #2Tejun Heo
The way namespace tags are implemented in sysfs is more complicated than necessary. As each tag is a pointer value and required to be non-NULL under a namespace enabled parent, there's no need to record separately what type each tag is. If multiple namespace types are needed, which currently aren't, we can simply compare the tag to a set of allowed tags in the superblock assuming that the tags, being pointers, won't have the same value across multiple types. This patch rips out kobj_ns_type handling from sysfs. sysfs now has an enable switch to turn on namespace under a node. If enabled, all children are required to have non-NULL namespace tags and filtered against the super_block's tag. kobject namespace determination is now performed in lib/kobject.c::create_dir() making sysfs_read_ns_type() unnecessary. The sanity checks are also moved. create_dir() is restructured to ease such addition. This removes most kobject namespace knowledge from sysfs proper which will enable proper separation and layering of sysfs. This is the second try. The first one was cb26a311578e ("sysfs: drop kobj_ns_type handling") which tried to automatically enable namespace if there are children with non-NULL namespace tags; however, it was broken for symlinks as they should inherit the target's tag iff namespace is enabled in the parent. This led to namespace filtering enabled incorrectly for wireless net class devices through phy80211 symlinks and thus network configuration failure. a1212d278c05 ("Revert "sysfs: drop kobj_ns_type handling"") reverted the commit. This shouldn't introduce any behavior changes, for real. v2: Dummy implementation of sysfs_enable_ns() for !CONFIG_SYSFS was missing and caused build failure. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-07Revert "sysfs: drop kobj_ns_type handling"Linus Torvalds
This reverts commit cb26a311578e67769e92a39a0a63476533cb7e12. It mysteriously causes NetworkManager to not find the wireless device for me. As far as I can tell, Tejun *meant* for this commit to not make any semantic changes, but there clearly are some. So revert it, taking into account some of the calling convention changes that happened in this area in subsequent commits. Cc: Tejun Heo <tj@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-11kobject: show debug info on delayed kobject releaseFengguang Wu
Useful for locating buggy drivers on kernel oops. It may add dozens of new lines to boot dmesg. DEBUG_KOBJECT_RELEASE is hopefully only enabled in debug kernels (like maybe the Fedora rawhide one, or at developers), so being a bit more verbose is likely ok. Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-03kobject: grab an extra reference on kobject->sd to allow duplicate deletesTejun Heo
sysfs currently has a rather weird behavior regarding removals. A directory removal would delete all files directly under it but wouldn't recurse into subdirectories, which, while a bit inconsistent, seems to make sense at the first glance as each directory is supposedly associated with a kobject and each kobject can take care of the directory deletion; however, this doesn't really hold as we have groups which can be directories without a kobject associated with it and require explicit deletions. We're in the process of separating out sysfs from kboject / driver core and want a consistent behavior. A removal should delete either only the specified node or everything under it. I think it is helpful to support recursive atomic removal and later patches will implement it. Such change means that a sysfs_dirent associated with kobject may be deleted before the kobject itself is removed if one of its ancestor gets removed before it. As sysfs_remove_dir() puts the base ref, we may end up with dangling pointer on descendants. This can be solved by holding an extra reference on the sd from kobject. Acquire an extra reference on the associated sysfs_dirent on directory creation and put it after removal. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-29Merge 3.12-rc3 into driver-core-nextGreg Kroah-Hartman
We want the driver core and sysfs fixes in here to make merges and development easier. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-27sysfs: Allow mounting without CONFIG_NETEric W. Biederman
In kobj_ns_current_may_mount the default should be to allow the mount. The test is only for a single kobj_ns_type at a time, and unless there is a reason to prevent it the mounting sysfs should be allowed. Subsystems that are not registered can't have are not involved so can't have a reason to prevent mounting sysfs. This is a bug-fix to commit 7dc5dbc879bd ("sysfs: Restrict mounting sysfs") that came in via the userns tree during the 3.12 merge window. Reported-and-tested-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>