linux-stable.git/drivers/hwmon/ftsteutates.c, branch linux-rolling-stable

hwmon: Use named initializers for arrays of i2c_device_data

2026-08-03T09:25:29+00:00

[ Upstream commit 4a9e6a9230c88a71916301b9fe6627413ebc2574 ]

While being less compact, using named initializers allows to more easily
see which members of the structs are assigned which value without having
to lookup the declaration of the struct. And it's also more robust
against changes to the struct definition.

The mentioned robustness is relevant for a planned change to struct
i2c_device_id that replaces .driver_data by an anonymous union.

While touching all these arrays, unify indention and usage of commas.

This patch doesn't modify the compiled arrays, only their representation
in source form benefits. The former was confirmed with x86 and arm64
builds.

Signed-off-by: Uwe Kleine-König (The Capable Hub) 
Link: https://lore.kernel.org/r/65b77bcd452752c36d866069cc5790b26d2bf8dc.1778688803.git.u.kleine-koenig@baylibre.com
Signed-off-by: Guenter Roeck 
Stable-dep-of: af01dab0c39a ("hwmon: (pmbus/max34440) block unsupported VIN and IIN limit registers")
Signed-off-by: Sasha Levin

hwmon: (ftsteutates) Rely on subsystem locking

2025-10-17T12:59:13+00:00

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck

hwmon: (ftsteutates) Fix TOCTOU race in fts_read()

2025-06-16T13:30:57+00:00

In the fts_read() function, when handling hwmon_pwm_auto_channels_temp,
the code accesses the shared variable data->fan_source[channel] twice
without holding any locks. It is first checked against
FTS_FAN_SOURCE_INVALID, and if the check passes, it is read again
when used as an argument to the BIT() macro.

This creates a Time-of-Check to Time-of-Use (TOCTOU) race condition.
Another thread executing fts_update_device() can modify the value of
data->fan_source[channel] between the check and its use. If the value
is changed to FTS_FAN_SOURCE_INVALID (0xff) during this window, the
BIT() macro will be called with a large shift value (BIT(255)).
A bit shift by a value greater than or equal to the type width is
undefined behavior and can lead to a crash or incorrect values being
returned to userspace.

Fix this by reading data->fan_source[channel] into a local variable
once, eliminating the race condition. Additionally, add a bounds check
to ensure the value is less than BITS_PER_LONG before passing it to
the BIT() macro, making the code more robust against undefined behavior.

This possible bug was found by an experimental static analysis tool
developed by our team.

Fixes: 1c5759d8ce05 ("hwmon: (ftsteutates) Replace fanX_source with pwmX_auto_channels_temp")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han 
Link: https://lore.kernel.org/r/20250606071640.501262-1-hanguidong02@gmail.com
Signed-off-by: Guenter Roeck

hwmon: Drop explicit initialization of struct i2c_device_id::driver_data to 0

2024-05-01T14:47:49+00:00

These drivers don't use the driver_data member of struct i2c_device_id,
so don't explicitly initialize this member.

This prepares putting driver_data in an anonymous union which requires
either no initialization or named designators. But it's also a nice
cleanup on its own.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20240430085654.1028864-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Guenter Roeck

hwmon: Switch i2c drivers back to use .probe()

2023-06-08T13:41:17+00:00

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

Signed-off-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20230505131718.1210071-1-u.kleine-koenig@pengutronix.de
[groeck: Added missing change in pmbus/acbel-fsg032.c]
Signed-off-by: Guenter Roeck

hwmon: ftsteutates: constify pointers to hwmon_channel_info

2023-04-19T14:08:35+00:00

Statically allocated array of pointed to hwmon_channel_info can be made
const for safety.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: Guenter Roeck

hwmon: (ftsteutates) Add support for fanX_fault attributes

2023-02-03T15:30:10+00:00

The driver knows internally when a fan is not connected,
but does not export this knowledge to userspace. Use the
standard fanX_fault attributes to notify userspace if a
fan is not connected.

Tested on a Fujitsu DS3401-B1.

Signed-off-by: Armin Wolf 
Link: https://lore.kernel.org/r/20230105225107.58308-4-W_Armin@gmx.de
Signed-off-by: Guenter Roeck

hwmon: (ftsteutates) Replace fanX_source with pwmX_auto_channels_temp

2023-02-03T15:30:10+00:00

Replace the nonstandard fanX_source attributes with the standardized
pwmX_auto_channels_temp attributes and document the special behaviour
associated with those attributes.

Tested on a Fujitsu DS3401-B1.

Signed-off-by: Armin Wolf 
Link: https://lore.kernel.org/r/20230105225107.58308-3-W_Armin@gmx.de
Signed-off-by: Guenter Roeck

hwmon: (ftsteutates) Convert to devm_hwmon_device_register_with_info()

2023-02-03T15:30:10+00:00

Convert driver to use devm_hwmon_device_register_with_info()
to reduce module size by ~30%.

Tested on a Fujitsu DS3401-B1.

Signed-off-by: Armin Wolf 
Link: https://lore.kernel.org/r/20230105225107.58308-2-W_Armin@gmx.de
Signed-off-by: Guenter Roeck

hwmon: (ftsteutates) Use devm_watchdog_register_device()

2023-02-03T15:30:09+00:00

Use devm_watchdog_register_device() to let devres take care
of unregistering the watchdog at device removal. Remove the
now pointless fts_remove() function.

Tested on a Fujitsu DS3401-B1.

Signed-off-by: Armin Wolf 
Link: https://lore.kernel.org/r/20221224041855.83981-4-W_Armin@gmx.de
Signed-off-by: Guenter Roeck