__kobject_del() is called from two places, in one where kobj is dereferenced
before and thus can't be NULL, and in the other the NULL check is done before
call. Drop unneeded conditional in __kobject_del().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200803083520.5460-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: 7589238a8c ("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>
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.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXtzmXg8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ymaAQCfZZ9prH3AMLF7DIkG3vMw0njLXt0An2FxrKYU
wetHRG4KL9vTkdz7+TqU
=t5LE
-----END PGP SIGNATURE-----
Merge tag 'driver-core-5.8-rc1' of 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
...
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>
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>
Commit 1fd7c3b438 ("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: 1fd7c3b438 ("kobject: Improve doc clarity kobject_init_and_add()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
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: aa30f47cf6 ("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>
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>
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>
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>
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>
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>
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. That merge issue is in fs/sysfs/group.c and Stephen has
posted the diff of what it should be to resolve this. I'll follow up
with that diff to this pull request.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCW3g86Q8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ynyXQCePaZSW8wft4b7nLN8RdZ98ATBru0Ani10lrJa
HQeQJRNbWU1AZ0ym7695
=tOaH
-----END PGP SIGNATURE-----
Merge tag 'driver-core-4.19-rc1' of 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
...
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>
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>
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>
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>
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.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWnLvPw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ynNzACgkzjPoBytJWbpWFt6SR6L33/u4kEAnRFvVCGL
s6ygQPQhZIjKk2Lxa2hC
=Zihy
-----END PGP SIGNATURE-----
Merge tag 'driver-core-4.16-rc1' of 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
...
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>
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>
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>
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>
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>
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>
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 a3fa71c40f ("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 5ce1aca814
("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>
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().
...
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>
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>
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>
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>
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
...
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>
This reverts commit eee0316497.
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>
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>
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>
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>
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>
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>
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 cb26a31157 ("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. a1212d278c
("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>
This reverts commit cb26a31157.
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>
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>
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>
