rtc: class: Switch to use hrtimer_setup()

hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.

Replace hrtimer_init() and the open coded initializat

rtc: class: Switch to use hrtimer_setup()

hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.

Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.

Patch was created by using Coccinelle.

Signed-off-by: Nam Cao <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Zack Rusin <[email protected]>
Acked-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/all/22f3f087ddbab1708583033c07c3b7fb17810110.1738746904.git.namcao@linutronix.de

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rtc: class: make rtc_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move

rtc: class: make rtc_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the rtc_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <[email protected]>
Suggested-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Ricardo B. Marliere <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>

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rtc: class: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Sign

rtc: class: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Signed-off-by: Christophe JAILLET <[email protected]>
Link: https://lore.kernel.org/r/4f2c049cb09d46fed336e22445c71988b4f340d6.1702962419.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Alexandre Belloni <[email protected]>

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driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
s

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <[email protected]>
Acked-by: Benjamin Tissoires <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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rtc: class: Fix potential memleak in devm_rtc_allocate_device()

devm_rtc_allocate_device() will alloc a rtc_device first, and then run
dev_set_name(). If dev_set_name() failed, the rtc_device will m

rtc: class: Fix potential memleak in devm_rtc_allocate_device()

devm_rtc_allocate_device() will alloc a rtc_device first, and then run
dev_set_name(). If dev_set_name() failed, the rtc_device will memleak.
Move devm_add_action_or_reset() in front of dev_set_name() to prevent
memleak.

unreferenced object 0xffff888110a53000 (size 2048):
comm "python3", pid 470, jiffies 4296078308 (age 58.882s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 08 30 a5 10 81 88 ff ff .........0......
08 30 a5 10 81 88 ff ff 00 00 00 00 00 00 00 00 .0..............
backtrace:
[<000000004aac0364>] kmalloc_trace+0x21/0x110
[<000000000ff02202>] devm_rtc_allocate_device+0xd4/0x400
[<000000001bdf5639>] devm_rtc_device_register+0x1a/0x80
[<00000000351bf81c>] rx4581_probe+0xdd/0x110 [rtc_rx4581]
[<00000000f0eba0ae>] spi_probe+0xde/0x130
[<00000000bff89ee8>] really_probe+0x175/0x3f0
[<00000000128e8d84>] __driver_probe_device+0xe6/0x170
[<00000000ee5bf913>] device_driver_attach+0x32/0x80
[<00000000f3f28f92>] bind_store+0x10b/0x1a0
[<000000009ff812d8>] drv_attr_store+0x49/0x70
[<000000008139c323>] sysfs_kf_write+0x8d/0xb0
[<00000000b6146e01>] kernfs_fop_write_iter+0x214/0x2d0
[<00000000ecbe3895>] vfs_write+0x61a/0x7d0
[<00000000aa2196ea>] ksys_write+0xc8/0x190
[<0000000046a600f5>] do_syscall_64+0x37/0x90
[<00000000541a336f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 24d23181e43d ("rtc: class: check return value when calling dev_set_name()")
Signed-off-by: Shang XiaoJing <[email protected]>
Reviewed-by: Yang Yingliang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>

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rtc: Directly use ida_alloc()/free()

Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu <[email protected]>
Signed-off-by: Alexandre Bello

rtc: Directly use ida_alloc()/free()

Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: remove uie_unsupported

uie_unsupported is not used by any drivers anymore, remove it.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/202203091

rtc: remove uie_unsupported

uie_unsupported is not used by any drivers anymore, remove it.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: fix use-after-free on device removal

If the irqwork is still scheduled or running while the RTC device is
removed, a use-after-free occurs in rtc_timer_do_work(). Cleanup the
timerqueue and en

rtc: fix use-after-free on device removal

If the irqwork is still scheduled or running while the RTC device is
removed, a use-after-free occurs in rtc_timer_do_work(). Cleanup the
timerqueue and ensure the work is stopped to fix this.

BUG: KASAN: use-after-free in mutex_lock+0x94/0x110
Write of size 8 at addr ffffff801d846338 by task kworker/3:1/41

Workqueue: events rtc_timer_do_work
Call trace:
mutex_lock+0x94/0x110
rtc_timer_do_work+0xec/0x630
process_one_work+0x5fc/0x1344
...

Allocated by task 551:
kmem_cache_alloc_trace+0x384/0x6e0
devm_rtc_allocate_device+0xf0/0x574
devm_rtc_device_register+0x2c/0x12c
...

Freed by task 572:
kfree+0x114/0x4d0
rtc_device_release+0x64/0x80
device_release+0x8c/0x1f4
kobject_put+0x1c4/0x4b0
put_device+0x20/0x30
devm_rtc_release_device+0x1c/0x30
devm_action_release+0x54/0x90
release_nodes+0x124/0x310
devres_release_group+0x170/0x240
i2c_device_remove+0xd8/0x314
...

Last potentially related work creation:
insert_work+0x5c/0x330
queue_work_on+0xcc/0x154
rtc_set_time+0x188/0x5bc
rtc_dev_ioctl+0x2ac/0xbd0
...

Signed-off-by: Vincent Whitchurch <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: expose RTC_FEATURE_UPDATE_INTERRUPT

Set RTC_FEATURE_UPDATE_INTERRUPT by default and clear it when it is not
supported.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: ht

rtc: expose RTC_FEATURE_UPDATE_INTERRUPT

Set RTC_FEATURE_UPDATE_INTERRUPT by default and clear it when it is not
supported.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: expose correction feature

Add a new feature for RTCs able to correct the oscillator imprecision. This
is also called offset or trimming. Such drivers have a .set_offset callback,
use that to se

rtc: expose correction feature

Add a new feature for RTCs able to correct the oscillator imprecision. This
is also called offset or trimming. Such drivers have a .set_offset callback,
use that to set the feature bit from the core.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: class: check return value when calling dev_set_name()

I got a null-ptr-deref report when doing fault injection test:

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:s

rtc: class: check return value when calling dev_set_name()

I got a null-ptr-deref report when doing fault injection test:

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:strcmp+0xc/0x20
Call Trace:
__devm_rtc_register_device.cold.7+0x16a/0x2df
rv3029_probe+0x4b1/0x770 [rtc_rv3029c2]
rv3029_i2c_probe+0x141/0x180 [rtc_rv3029c2]
i2c_device_probe+0xa07/0xbb0
really_probe+0x285/0xc30

If dev_set_name() fails, dev_name() is null, it causes null-ptr-deref,
we need check the return value of dev_set_name().

Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: class: don't call cdev_device_del() when cdev_device_add() failed

I got a null-ptr-deref report when doing fault injection test:

general protection fault, probably for non-canonical address 0x

rtc: class: don't call cdev_device_del() when cdev_device_add() failed

I got a null-ptr-deref report when doing fault injection test:

general protection fault, probably for non-canonical address 0xdffffc0000000022: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000110-0x0000000000000117]
RIP: 0010:device_del+0x132/0xdc0
Call Trace:
cdev_device_del+0x1a/0x80
devm_rtc_unregister_device+0x37/0x80
release_nodes+0xc3/0x3b0

If cdev_device_add() fails, 'dev->p' is not set, it causes
null-ptr-deref when calling cdev_device_del(). Registering
character device is optional, we don't return error code
here, so introduce a new flag 'RTC_NO_CDEV' to indicate
if it has character device, cdev_device_del() is called
when this bit is not set.

Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: class: remove bogus documentation

rtc_device_unregister is gone since commit fdcfd854333b ("rtc: rework
rtc_register_device() resource management"). Remove its documentation.

Signed-off-by: Al

rtc: class: remove bogus documentation

rtc_device_unregister is gone since commit fdcfd854333b ("rtc: rework
rtc_register_device() resource management"). Remove its documentation.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: introduce features bitfield

Introduce a bitfield to allow the drivers to announce the available
features for an RTC.

The main use case would be to better handle alarms, that could be present
o

rtc: introduce features bitfield

Introduce a bitfield to allow the drivers to announce the available
features for an RTC.

The main use case would be to better handle alarms, that could be present
or not or have a minute resolution or may need a correct week day to be set.

Use the newly introduced RTC_FEATURE_ALARM bit to then test whether alarms
are available instead of relying on the presence of ops->set_alarm.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: fix RTC removal

Since the rtc_register_device, removing an RTC device will end with a
refcount_t: underflow; use-after-free warning since put_device is called
twice in the device tear down path

rtc: fix RTC removal

Since the rtc_register_device, removing an RTC device will end with a
refcount_t: underflow; use-after-free warning since put_device is called
twice in the device tear down path.

Fixes: fdcfd854333b ("rtc: rework rtc_register_device() resource management")
Signed-off-by: Alexandre Belloni <[email protected]>
Reviewed-by: Bartosz Golaszewski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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ntp: Make the RTC sync offset less obscure

The current RTC set_offset_nsec value is not really intuitive to
understand.

tsched twrite(t2.tv_sec - 1) t2 (seconds increment)

The offset is

ntp: Make the RTC sync offset less obscure

The current RTC set_offset_nsec value is not really intuitive to
understand.

tsched twrite(t2.tv_sec - 1) t2 (seconds increment)

The offset is calculated from twrite based on the assumption that t2 -
twrite == 1s. That means for the MC146818 RTC the offset needs to be
negative so that the write happens 500ms before t2.

It's easier to understand when the whole calculation is based on t2. That
avoids negative offsets and the meaning is obvious:

t2 - twrite: The time defined by the chip when seconds increment
after the write.

twrite - tsched: The time for the transport to the point where the chip
is updated.

==> set_offset_nsec = t2 - tsched
ttransport = twrite - tsched
tRTCinc = t2 - twrite
==> set_offset_nsec = ttransport + tRTCinc

tRTCinc is a chip property and can be obtained from the data sheet.

ttransport depends on how the RTC is connected. It is close to 0 for
directly accessible RTCs. For RTCs behind a slow bus, e.g. i2c, it's the
time required to send the update over the bus. This can be estimated or
even calibrated, but that's a different problem.

Adjust the implementation and update comments accordingly.

Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: core: Make the sync offset default more realistic

The offset which is used to steer the start of an RTC synchronization
update via rtc_set_ntp_time() is huge. The math behind this is:

tsched

rtc: core: Make the sync offset default more realistic

The offset which is used to steer the start of an RTC synchronization
update via rtc_set_ntp_time() is huge. The math behind this is:

tsched twrite(t2.tv_sec - 1) t2 (seconds increment)

twrite - tsched is the transport time for the write to hit the device.

t2 - twrite depends on the chip and is for most chips one second.

The rtc_set_ntp_time() calculation of tsched is:

tsched = t2 - 1sec - (t2 - twrite)

The default for the sync offset is 500ms which means that twrite - tsched
is 500ms assumed that t2 - twrite is one second.

This is 0.5 seconds off for RTCs which are directly accessible by IO writes
and probably for the majority of i2C/SPI based RTC off by an order of
magnitude. Set it to 5ms which should bring it closer to reality.

The default can be adjusted by drivers (rtc_cmos does so) and could be
adjusted further by a calibration method which is an orthogonal problem.

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Acked-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: destroy mutex when releasing the device

Not destroying mutexes doesn't lead to resource leak but it's the correct
thing to do for mutex debugging accounting.

Signed-off-by: Bartosz Golaszewski

rtc: destroy mutex when releasing the device

Not destroying mutexes doesn't lead to resource leak but it's the correct
thing to do for mutex debugging accounting.

Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: shrink devm_rtc_allocate_device()

We don't need to use devres_alloc() & devres_add() manually if all we
want to manage is a single pointer. We can shrink the code by using
devm_add_action_or_re

rtc: shrink devm_rtc_allocate_device()

We don't need to use devres_alloc() & devres_add() manually if all we
want to manage is a single pointer. We can shrink the code by using
devm_add_action_or_reset() instead. The number of allocations stays
the same.

Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: rework rtc_register_device() resource management

rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres

rtc: rework rtc_register_device() resource management

rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: nvmem: remove nvram ABI

The nvram sysfs attributes have been deprecated at least since v4.13, more
than 3 years ago and nobody ever complained about the deprecation warning.

Remove the sysfs a

rtc: nvmem: remove nvram ABI

The nvram sysfs attributes have been deprecated at least since v4.13, more
than 3 years ago and nobody ever complained about the deprecation warning.

Remove the sysfs attributes now.

[Bartosz: remove the declaration of rtc_nvmem_unregister()]

Signed-off-by: Alexandre Belloni <[email protected]>
Signed-off-by: Bartosz Golaszewski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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rtc: class: remove redundant assignment to variable err

The variable err is being initialized with a value that is never read
and it is being updated later with a new value. The initialization
is re

rtc: class: remove redundant assignment to variable err

The variable err is being initialized with a value that is never read
and it is being updated later with a new value. The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>

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rtc: class: avoid unnecessary lookup in hctosys

rtc_hctosys is only called when the relevant RTC is found, avoid looking it
up while we already have a pinter to the proper struct rtc_device.

Link:

rtc: class: avoid unnecessary lookup in hctosys

rtc_hctosys is only called when the relevant RTC is found, avoid looking it
up while we already have a pinter to the proper struct rtc_device.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>

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rtc: class: support hctosys from modular RTC drivers

Due to distribution constraints it may not be possible to statically
compile the required RTC driver into the kernel.

Expand RTC_HCTOSYS support

rtc: class: support hctosys from modular RTC drivers

Due to distribution constraints it may not be possible to statically
compile the required RTC driver into the kernel.

Expand RTC_HCTOSYS support to cover all RTC devices (statically compiled
or not) by checking at the end of RTC device registration whether the
time should be synced.

Signed-off-by: Steve Muckle <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>

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rtc: class: add debug message when registration fails

Add a message when __rtc_register_device fails because rtc->ops is NULL.
This may only happen when developing a new driver so use dev_dbg to avo

rtc: class: add debug message when registration fails

Add a message when __rtc_register_device fails because rtc->ops is NULL.
This may only happen when developing a new driver so use dev_dbg to avoid
compiling it in by default.

Signed-off-by: Alexandre Belloni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>

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