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: bus: constify bus_get()

It's funny to think about getting a reference count of a constant
structure pointer, but this locks into place the private data
"underneath" the struct bus_type(

driver core: bus: constify bus_get()

It's funny to think about getting a reference count of a constant
structure pointer, but this locks into place the private data
"underneath" the struct bus_type() which is important to not go away
while we are working with the bus structure for some callbacks.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-27-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constify driver_find()

The driver_find() function can now take a const * to bus_type, not just
a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.k

driver core: bus: constify driver_find()

The driver_find() function can now take a const * to bus_type, not just
a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-26-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constify bus_rescan_devices()

The bus_rescan_devices() function was missed in the previous change of
the bus_for_each* constant pointer changes, so fix it up now to take a
const *

driver core: bus: constify bus_rescan_devices()

The bus_rescan_devices() function was missed in the previous change of
the bus_for_each* constant pointer changes, so fix it up now to take a
const * to struct bus_type.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-25-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: mark the struct bus_type for sysfs callbacks as constant

struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, t

driver core: bus: mark the struct bus_type for sysfs callbacks as constant

struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
bus_type to be moved to read-only memory.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Ben Widawsky <bwidawsk@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hu Haowen <src.res@email.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Acked-by: Ilya Dryomov <idryomov@gmail.com> # rbd
Acked-by: Ira Weiny <ira.weiny@intel.com> # cxl
Reviewed-by: Alex Shi <alexs@kernel.org>
Acked-by: Iwona Winiarska <iwona.winiarska@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com> # scsi
Link: https://lore.kernel.org/r/20230313182918.1312597-23-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: bus: Handle early calls to bus_to_subsys()

When calling soc_device_match() from early_initcall(), bus_kset is still
NULL, causing a crash:

Unable to handle kernel NULL pointer dere

driver core: bus: Handle early calls to bus_to_subsys()

When calling soc_device_match() from early_initcall(), bus_kset is still
NULL, causing a crash:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000028
...
Call trace:
__lock_acquire+0x530/0x20f0
lock_acquire.part.0+0xc8/0x210
lock_acquire+0x64/0x80
_raw_spin_lock+0x4c/0x60
bus_to_subsys+0x24/0xac
bus_for_each_dev+0x30/0xcc
soc_device_match+0x4c/0xe0
r8a7795_sysc_init+0x18/0x60
rcar_sysc_pd_init+0xb0/0x33c
do_one_initcall+0x128/0x2bc

Before, bus_for_each_dev() handled this gracefully by checking that
the back-pointer to the private structure was valid.

Fix this by adding a NULL check for bus_kset to bus_to_subsys().

Fixes: 83b9148df2c95e23 ("driver core: bus: bus iterator cleanups")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/0a92979f6e790737544638e8a4c19b0564e660a2.1676983596.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: update my copyright notice

There's been some work done recently to the drivers/base/bus.c file so
update the copyright notice in it to make those who track those types of
things ha

driver core: bus: update my copyright notice

There's been some work done recently to the drivers/base/bus.c file so
update the copyright notice in it to make those who track those types of
things have an easier job.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230210091318.733561-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: add bus_get_dev_root() function

Instead of poking around in the struct bus_type directly for the
dev_root pointer, provide a function to return it properly reference
counted, if it

driver core: bus: add bus_get_dev_root() function

Instead of poking around in the struct bus_type directly for the
dev_root pointer, provide a function to return it properly reference
counted, if it is present in the bus. This will be needed to move the
pointer out of struct bus_type in the future.

Use the function in the driver core code at the same time it is
introduced to verify that it works properly.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230209093556.19132-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constify bus_unregister()

The bus_unregister() function can now take a const * to bus_type, not
just a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://

driver core: bus: constify bus_unregister()

The bus_unregister() function can now take a const * to bus_type, not
just a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-22-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constify some internal functions

The functions add_probe_files() and remove_probe_files() should be
taking a const * to bus_type, not just a *, so fix that up. These
functions sho

driver core: bus: constify some internal functions

The functions add_probe_files() and remove_probe_files() should be
taking a const * to bus_type, not just a *, so fix that up. These
functions should really be removed entirely and an attribute group used
instead, but for now, make this change so that other const work can
continue.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-21-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constify bus_get_kset()

The bus_get_kset() function should be taking a const * to bus_type, not
just a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://

driver core: bus: constify bus_get_kset()

The bus_get_kset() function should be taking a const * to bus_type, not
just a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-20-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: constify bus_register/unregister_notifier()

The bus_register_notifier() and bus_unregister_notifier() functions
should be taking a const * to bus_type, not just a * so fix that up.

driver core: bus: constify bus_register/unregister_notifier()

The bus_register_notifier() and bus_unregister_notifier() functions
should be taking a const * to bus_type, not just a * so fix that up.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-19-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: remove private pointer from struct bus_type

Now that the driver code has been refactored to not rely on the pointer
from a struct bus_type to the private structure it can be safely remo

driver core: remove private pointer from struct bus_type

Now that the driver code has been refactored to not rely on the pointer
from a struct bus_type to the private structure it can be safely removed
from the structure entirely.

This will allow most bus_type structures to now be marked as const.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-18-gregkh@linuxfoundation.org
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: bus: clean up driver_find()

Convert the driver_find() function to use bus_to_subsys() and not use
the back-pointer to the private structure.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>

driver core: bus: clean up driver_find()

Convert the driver_find() function to use bus_to_subsys() and not use
the back-pointer to the private structure.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: move driver_find() to bus.c

This function really is a bus function, not a driver one, so move it
from driver.c to bus.c so that we can clean up some internal bus logic
easier.

Cc: "Raf

driver core: move driver_find() to bus.c

This function really is a bus function, not a driver one, so move it
from driver.c to bus.c so that we can clean up some internal bus logic
easier.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-15-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

driver core: bus: clean up bus_sort_breadthfirst()

Convert the bus_sort_breadthfirst() function to use bus_to_subsys() and
not use the back-pointer to the private structure.

This also allows us to

driver core: bus: clean up bus_sort_breadthfirst()

Convert the bus_sort_breadthfirst() function to use bus_to_subsys() and
not use the back-pointer to the private structure.

This also allows us to get rid of bus_get_device_klist() which was only
being used by this one internal function.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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