Commit Graph

159 Commits

Author SHA1 Message Date
Lin Yi
122f8ec7b7 lib : kobject: fix refcount imblance on kobject_rename
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>
2019-06-19 19:27:39 +02:00
Greg Kroah-Hartman
70e16a620e kobject: clean up the kobject add documentation a bit more
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>
2019-05-03 08:26:51 +02:00
Tobin C. Harding
ed856349dc kobject: Fix kernel-doc comment first line
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>
2019-05-02 09:28:18 +02:00
Tobin C. Harding
8fd7c302b3 kobject: Remove docstring reference to kset
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>
2019-05-02 09:24:06 +02:00
Colin Ian King
3d378dc713 kobject: fix dereference before null check on kobj
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>
2019-05-01 15:08:38 +02:00
Tobin C. Harding
1fd7c3b438 kobject: Improve doc clarity kobject_init_and_add()
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>
2019-04-28 18:16:03 +02:00
Tobin C. Harding
92067f8438 kobject: Improve docs for kobject_add/del
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>
2019-04-28 18:16:03 +02:00
Kimberly Brown
aa30f47cf6 kobject: Add support for default attribute groups to kobj_type
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>
2019-04-25 22:06:10 +02:00
Eric Biggers
7ab35a14de kobject: make kset_get_ownership() 'static'
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>
2019-01-22 14:25:26 +01:00
Ezequiel Garcia
186bddb28f kref/kobject: Improve documentation
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>
2018-12-06 13:57:03 +01:00
Linus Torvalds
a18d783fed 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
  ...
2018-08-18 11:44:53 -07:00
Dmitry Torokhov
d028b6f703 kobject: kset_create_and_add() - fetch ownership info from parent
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>
2018-07-20 23:44:35 -07:00
Dmitry Torokhov
5f81880d52 sysfs, kobject: allow creating kobject belonging to arbitrary users
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>
2018-07-20 23:44:35 -07:00
Guenter Roeck
77d2a24b61 kobject: Replace strncpy with memcpy
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>
2018-07-07 17:40:20 +02:00
Dmitry Vyukov
3e14c6abbf kobject: don't use WARN for registration failures
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>
2018-04-23 13:14:55 +02:00
Andy Shevchenko
82d1f1178a lib/kobject: Join string literals back
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>
2018-03-15 14:38:55 +01:00
Linus Torvalds
47fcc0360c 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
  ...
2018-02-01 10:00:28 -08:00
Bart Van Assche
172856eac7 kobject: Export kobj_ns_grab_current() and kobj_ns_drop()
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>
2018-01-23 11:35:04 -05:00
Greg Kroah-Hartman
045c5f75b7 kobject: Remove redundant license text
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>
2017-12-07 18:36:43 +01:00
Greg Kroah-Hartman
d9d16e16a3 kobject: add SPDX identifiers to all kobject files
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>
2017-12-07 18:36:43 +01:00
Jan Kara
c70c176ff8 kobject: Export kobject_get_unless_zero()
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>
2017-03-22 20:11:35 -06:00
Gabriel Somlo
2fe829aca9 kobject: export kset_find_obj() for module use
Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-09 17:36:34 -08:00
Rasmus Villemoes
f773f32d71 lib/kobject.c: use kvasprintf_const for formatting ->name
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>
2015-11-06 17:50:42 -08:00
Gabriel Somlo
fa40ae3444 kobject: move EXPORT_SYMBOL() macros next to corresponding definitions
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>
2015-10-04 11:46:16 +01:00
Nicolas Iooss
8db1486065 include, lib: add __printf attributes to several function prototypes
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>
2015-07-17 16:39:53 -07:00