module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driv

module: don't ignore sysfs_create_link() failures

[ Upstream commit 85d2b0aa170351380be39fe4ff7973df1427fe76 ]

The sysfs_create_link() return code is marked as __must_check, but the
module_add_driver() function tries hard to not care, by assigning the
return code to a variable. When building with 'make W=1', gcc still
warns because this variable is only assigned but not used:

drivers/base/module.c: In function 'module_add_driver':
drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable]

Rework the code to properly unwind and return the error code to the
caller. My reading of the original code was that it tries to
not fail when the links already exist, so keep ignoring -EEXIST
errors.

Fixes: e17e0f51aeea ("Driver core: show drivers in /sys/module/")
See-also: 4a7fb6363f2d ("add __must_check to device management code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

driver core: class: make class_register() take a const *

Now that the class code is cleaned up to not modify the class pointer
registered with it, change class_register() to take a const * to allow

driver core: class: make class_register() take a const *

Now that the class code is cleaned up to not modify the class pointer
registered with it, change class_register() to take a const * to allow
the structure to be placed into read-only memory.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023040248-customary-release-4aec@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: make sysfs_dev_char_kobj static

Nothing outside of drivers/base/core.c uses sysfs_dev_char_kobj, so
make it static and document what it is used for so we remember it the
next time we to

driver core: make sysfs_dev_char_kobj static

Nothing outside of drivers/base/core.c uses sysfs_dev_char_kobj, so
make it static and document what it is used for so we remember it the
next time we touch it 15 years from now.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: clean up the logic to determine which /sys/dev/ directory to use

When a dev_t is set in a struct device, an symlink in /sys/dev/ is
created for it either under /sys/dev/block/ or /sys/d

driver core: clean up the logic to determine which /sys/dev/ directory to use

When a dev_t is set in a struct device, an symlink in /sys/dev/ is
created for it either under /sys/dev/block/ or /sys/dev/char/ depending
on the device type.

The logic to determine this would trigger off of the class of the
object, and the kobj_type set in that location. But it turns out that
this deep nesting isn't needed at all, as it's either a choice of block
or "everything else" which is a char device. So make the logic a lot
more simple and obvious, and remove the incorrect comments in the code
that tried to document something that was not happening at all (it is
impossible to set class->dev_kobj to NULL as the class core prevented
that from happening.

This removes the only place that class->dev_kobj was being used, so
after this, it can be removed entirely.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: core: move to use class_to_subsys()

There are a number of places in core.c that need access to the private
subsystem structure of struct class, so move them to use
class_to_subsys() ins

driver core: core: move to use class_to_subsys()

There are a number of places in core.c that need access to the private
subsystem structure of struct class, so move them to use
class_to_subsys() instead of accessing it directly.

This requires exporting class_to_subsys() out of class.c, but keeping it
local to the driver core.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: move sysfs_dev_char_kobj out of class.h

The structure sysfs_dev_char_kobj is local only to the driver core code,
so move it out of the global class.h file and into the internal base.h
f

driver core: move sysfs_dev_char_kobj out of class.h

The structure sysfs_dev_char_kobj is local only to the driver core code,
so move it out of the global class.h file and into the internal base.h
file as no one else should be touching this symbol.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230327160319.513974-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: move documentation for lock_key to proper location.

In commit 37e98d9bedb5 ("driver core: bus: move lock_class_key into
dynamic structure"), the lock_key variable moved out of stru

driver core: bus: move documentation for lock_key to proper location.

In commit 37e98d9bedb5 ("driver core: bus: move lock_class_key into
dynamic structure"), the lock_key variable moved out of struct bus_type
and into struct subsys_private, yet the documentation for it did not
move. Fix that up and place the documentation comment in the correct
location.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Fixes: 37e98d9bedb5 ("driver core: bus: move lock_class_key into dynamic structure")
Link: https://lore.kernel.org/r/20230324090814.386654-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: base.h: remove extern from function prototypes

The kernel coding style does not require 'extern' in function prototypes
in .h files, so remove them from drivers/base/base.h as they are

driver core: base.h: remove extern from function prototypes

The kernel coding style does not require 'extern' in function prototypes
in .h files, so remove them from drivers/base/base.h as they are not
needed.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230324122711.2664537-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constantify bus_register()

bus_register() is now safe to take a constant * to bus_type, so make
that change and mark the subsys_private bus_type * constant as well.

Cc: "Rafael J.

driver core: bus: constantify bus_register()

bus_register() is now safe to take a constant * to bus_type, so make
that change and mark the subsys_private bus_type * constant as well.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-24-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: move dev_root out of struct bus_type

Now that all accesses of dev_root is through the bus_get_dev_root()
call, move the pointer out of struct bus_type and into the private
dynamic

driver core: bus: move dev_root out of struct bus_type

Now that all accesses of dev_root is through the bus_get_dev_root()
call, move the pointer out of struct bus_type and into the private
dynamic structure, subsys_private.

With this change, there is no modifiable portions of struct bus_type so
it can be marked as a constant structure and moved to read-only memory.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-22-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: Make state_synced device attribute writeable

If the file is written to and sync_state() hasn't been called for the
device yet, then call sync_state() for the device independent of the
s

driver core: Make state_synced device attribute writeable

If the file is written to and sync_state() hasn't been called for the
device yet, then call sync_state() for the device independent of the
state of its consumers.

This is useful for supplier devices that have one or more consumers that
don't have a driver but the consumers are in a state that don't use the
resources supplied by the supplier device.

This gives finer grained control than using the
fw_devlink.sync_state=timeout kernel commandline parameter.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: Add fw_devlink.sync_state command line param

When all devices that could probe have finished probing (based on
deferred_probe_timeout configuration or late_initcall() when
!CONFIG_MODUL

driver core: Add fw_devlink.sync_state command line param

When all devices that could probe have finished probing (based on
deferred_probe_timeout configuration or late_initcall() when
!CONFIG_MODULES), this parameter controls what to do with devices that
haven't yet received their sync_state() calls.

fw_devlink.sync_state=strict is the default and the driver core will
continue waiting on all consumers of a device to probe successfully
before sync_state() is called for the device. This is the default
behavior since calling sync_state() on a device when all its consumers
haven't probed could make some systems unusable/unstable. When this
option is selected, we also print the list of devices that haven't had
sync_state() called on them by the time all devices the could probe have
finished probing.

fw_devlink.sync_state=timeout will cause the driver core to give up
waiting on consumers and call sync_state() on any devices that haven't
yet received their sync_state() calls. This option is provided for
systems that won't become unusable/unstable as they might be able to
save power (depends on state of hardware before kernel starts) if all
devices get their sync_state().

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

Revert "devtmpfs: remove return value of devtmpfs_delete_node()"

This reverts commit 9d3fe6aa6b9517408064c7c3134187e8ec77dbf7 as it is
reported to cause boot regressions.

Link: https://lore.kernel.

Revert "devtmpfs: remove return value of devtmpfs_delete_node()"

This reverts commit 9d3fe6aa6b9517408064c7c3134187e8ec77dbf7 as it is
reported to cause boot regressions.

Link: https://lore.kernel.org/r/Y+rSXg14z1Myd8Px@dev-arch.thelio-3990X
Reported-by: Nathan Chancellor <nathan@kernel.org>
Cc: Longlong Xia <xialonglong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

devtmpfs: remove return value of devtmpfs_delete_node()

The only caller of device_del() does not check the return value. And
there's nothing we can do when cleaning things up on a remove path.
Let's

devtmpfs: remove return value of devtmpfs_delete_node()

The only caller of device_del() does not check the return value. And
there's nothing we can do when cleaning things up on a remove path.
Let's make it a void function.

Signed-off-by: Longlong Xia <xialonglong1@huawei.com>
Link: https://lore.kernel.org/r/20230210095444.4067307-4-xialonglong1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: create bus_is_registered()

A local function to the driver core to determine if a bus really is
registered with the kernel or not. To be used only by the driver core
code, as part of th

driver core: create bus_is_registered()

A local function to the driver core to determine if a bus really is
registered with the kernel or not. To be used only by the driver core
code, as part of the driver registration path as it's not really "safe"
because the bus could be unregistered instantly after being called.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-17-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: add local subsys_get and subsys_put functions

We need to control the reference count of the subsys private structure
instead of directly manipulating the kset reference count of it, so

driver core: add local subsys_get and subsys_put functions

We need to control the reference count of the subsys private structure
instead of directly manipulating the kset reference count of it, so wrap
that logic up in a subsys_get() and subsys_put() function to make it more
obvious as to what is happening.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: move lock_class_key into dynamic structure

Move the lock_class_key structure out of struct bus_type and into the
dynamic structure we create already for all bus_types registered wi

driver core: bus: move lock_class_key into dynamic structure

Move the lock_class_key structure out of struct bus_type and into the
dynamic structure we create already for all bus_types registered with
the kernel. This saves on static space and removes one more writable
field in struct bus_type.

In the future, the same field can be moved out of the struct class logic
because it shares this same private structure.

Most everyone will never notice this change, as lockdep is not enabled
in real systems so no memory or logic changes are happening for them.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230201083349.4038660-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: device_get_devnode() should take a const *

device_get_devnode() should take a constant * to struct device as it
does not modify it in any way, so modify the function definition to do
th

driver core: device_get_devnode() should take a const *

device_get_devnode() should take a constant * to struct device as it
does not modify it in any way, so modify the function definition to do
this and move it out of device.h as it does not need to be exposed to
the whole kernel tree.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Won Chung <wonchung@google.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-8-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: move bus notifier logic into bus.c

The logic to touch the bus notifier was open-coded in numberous places
in the driver core. Clean that up by creating a local bus_notify()
functi

driver core: bus: move bus notifier logic into bus.c

The logic to touch the bus notifier was open-coded in numberous places
in the driver core. Clean that up by creating a local bus_notify()
function and have everyone call this function instead, making the
reading of the caller code simpler and easier to maintain over time.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230111092331.3946745-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...