linux.git/drivers/of/kobj.c, branch v7.3-rc2

of: kobj: export of_node_ktype for use by modules

2026-07-21T21:39:35+00:00

of_node_init() is a static inline that references of_node_ktype when
CONFIG_OF_KOBJ=y. Any module that calls of_node_init() will therefore
have an unresolved reference to of_node_ktype at load time, because
the symbol is defined in drivers/of/kobj.c but was never exported.

This causes a modpost build error when CONFIG_OF_KOBJ=y and
CONFIG_DRIVER_PE_KUNIT_TEST=m:

  ERROR: modpost: "of_node_ktype"
  [drivers/base/test/property-entry-test.ko] undefined!

Add EXPORT_SYMBOL_IF_KUNIT(of_node_ktype) so that modules such as the
KUnit property-entry test can call of_node_init() without hitting this
linker error.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202607181651.RnUuV8n6-lkp@intel.com/
Signed-off-by: Xu Yang 
Acked-by: Rob Herring (Arm) 
Acked-by: Andy Shevchenko 
Link: https://lore.kernel.org/oe-kbuild-all/202607181651.RnUuV8n6-lkp@intel.com/
Link: https://patch.msgid.link/20260721105448.2109894-2-xu.yang_2@oss.nxp.com
[ Add empty line before the kunit include. - Danilo ]
Signed-off-by: Danilo Krummrich

sysfs: treewide: switch back to bin_attribute::read()/write()

2025-06-17T08:44:13+00:00

The bin_attribute argument of bin_attribute::read() is now const.
This makes the _new() callbacks unnecessary. Switch all users back.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20250530-sysfs-const-bin_attr-final-v3-3-724bfcf05b99@weissschuh.net
Signed-off-by: Greg Kroah-Hartman

of: Constify 'struct bin_attribute'

2024-12-31T13:55:16+00:00

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20241222-sysfs-const-bin_attr-of-v1-1-99cc2e8c2a55@weissschuh.net
Signed-off-by: Rob Herring (Arm)

of: Constify safe_name() kobject arg

2024-10-15T13:58:36+00:00

The kobject is not modified by safe_name() function, so make it const.

Reviewed-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20241010-dt-const-v1-6-87a51f558425@kernel.org
Signed-off-by: Rob Herring (Arm)

of: Constify struct property pointers

2024-10-15T13:58:36+00:00

Most accesses to struct property do not modify it, so constify struct
property pointers where ever possible in the DT core code.

Reviewed-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20241010-dt-const-v1-4-87a51f558425@kernel.org
Signed-off-by: Rob Herring (Arm)

of: make of_node_ktype constant

2023-02-06T17:03:00+00:00

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definition to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh 
Link: https://lore.kernel.org/r/20230204-kobj_type-of-v1-1-5910c8ecb7a3@weissschuh.net
Signed-off-by: Rob Herring

of: kobj: make of_node_is_(initialized|attached) parameters const

2021-10-20T18:37:25+00:00

of_node_is_initialized() and of_node_is_attached() don't modify the node
objects passed to them, so those parameters should be const.

Signed-off-by: Nathan Lynch 
Link: https://lore.kernel.org/r/20211014173023.2117799-1-nathanl@linux.ibm.com
Signed-off-by: Rob Herring

of: Don't allow __of_attached_node_sysfs() without CONFIG_SYSFS

2021-08-23T18:52:09+00:00

Trying to boot without SYSFS, but with OF_DYNAMIC quickly
results in a crash:

[    0.088460] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
[...]
[    0.103927] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.14.0-rc3 #4179
[    0.105810] Hardware name: linux,dummy-virt (DT)
[    0.107147] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
[    0.108876] pc : kernfs_find_and_get_ns+0x3c/0x7c
[    0.110244] lr : kernfs_find_and_get_ns+0x3c/0x7c
[...]
[    0.134087] Call trace:
[    0.134800]  kernfs_find_and_get_ns+0x3c/0x7c
[    0.136054]  safe_name+0x4c/0xd0
[    0.136994]  __of_attach_node_sysfs+0xf8/0x124
[    0.138287]  of_core_init+0x90/0xfc
[    0.139296]  driver_init+0x30/0x4c
[    0.140283]  kernel_init_freeable+0x160/0x1b8
[    0.141543]  kernel_init+0x30/0x140
[    0.142561]  ret_from_fork+0x10/0x18

While not having sysfs isn't a very common option these days,
it is still expected that such configuration would work.

Paper over it by bailing out from __of_attach_node_sysfs() if
CONFIG_SYSFS isn't enabled.

Signed-off-by: Marc Zyngier 
Link: https://lore.kernel.org/r/20210820144722.169226-1-maz@kernel.org
Signed-off-by: Rob Herring

of: Fix a refcounting bug in __of_attach_node_sysfs()

2020-05-28T01:30:25+00:00

The problem in this code is that if kobject_add() fails, then it should
call of_node_put(np) to drop the reference count.  I've actually moved
the of_node_get(np) later in the function to avoid needing to do clean
up.

Fixes: 5b2c2f5a0ea3 ("of: overlay: add missing of_node_get() in __of_attach_node_sysfs")
Signed-off-by: Dan Carpenter 
Signed-off-by: Rob Herring

of: overlay: add missing of_node_get() in __of_attach_node_sysfs

2018-11-09T06:10:53+00:00

There is a matching of_node_put() in __of_detach_node_sysfs()

Remove misleading comment from function header comment for
of_detach_node().

This patch may result in memory leaks from code that directly calls
the dynamic node add and delete functions directly instead of
using changesets.

This commit should result in powerpc systems that dynamically
allocate a node, then later deallocate the node to have a
memory leak when the node is deallocated.

The next commit will fix the leak.

Tested-by: Alan Tull 
Acked-by: Michael Ellerman  (powerpc)
Signed-off-by: Frank Rowand