Simply copying shared data to a local variable cannot prevent data
races. The compiler is allowed to optimize away the local copy and
re-read the shared memory, causing a Time-of-Check Time-of-Use (TOCTOU)
issue if the data changes between the check and the usage.

To enforce the use of the local variable, use READ_ONCE() when reading
the shared data and WRITE_ONCE() when updating it. Apply these macros to
the three identified locations (curr_sense, adc, and fault) where local
variables are used for error validation, ensuring the value remains
consistent.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Closes: https://lore.kernel.org/all/6fe17868327207e8b850cf9f88b7dc58b2021f73.camel@decadent.org.uk/
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Fixes: b8d5acdcf525 ("hwmon: (max16065) Use local variable to avoid TOCTOU")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://lore.kernel.org/r/20260203121443.5482-1-hanguidong02@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

In max16065_current_show, data->curr_sense is read twice: once for the
error check and again for the calculation. Since
i2c_smbus_read_byte_data returns negative error codes on failure, if the
data changes to an error code between the check and the use, ADC_TO_CURR
results in an incorrect calculation.

Read data->curr_sense into a local variable to ensure consistency. Note
that data->curr_gain is constant and safe to access directly.

This aligns max16065_current_show with max16065_input_show, which
already uses a local variable for the same reason.

Link: https://lore.kernel.org/all/CALbr=LYJ_ehtp53HXEVkSpYoub+XYSTU8Rg=o1xxMJ8=5z8B-g@mail.gmail.com/
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://lore.kernel.org/r/20251128124709.3876-1-hanguidong02@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Chips reporting overcurrent alarms report it in the second alarm register.
That means the second alarm register has to be read, even if the chip only
supports 8 or fewer ADC channels.

MAX16067 and MAX16068 report undervoltage and overvoltage alarms in
separate registers. Fold register contents together to report both with
the existing alarm attribute. This requires actually storing the chip type
in struct max16065_data. Rename the variable 'chip' to match the variable
name used in the probe function.

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Writing large limits resulted in overflows as reported by module tests.

in0_lcrit: Suspected overflow: [max=5538, read 0, written 2147483647]
in0_crit: Suspected overflow: [max=5538, read 0, written 2147483647]
in0_min: Suspected overflow: [max=5538, read 0, written 2147483647]

Fix the problem by clamping prior to multiplications and the use of
DIV_ROUND_CLOSEST, and by using consistent variable types.

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

The function i2c_match_id() is used to fetch the matching ID from
the i2c_device_id table. This is often used to then retrieve the
matching driver_data. This can be done in one step with the helper
i2c_get_match_data().

This helper has a couple other benefits:
 * It doesn't need the i2c_device_id passed in so we do not need
   to have that forward declared, allowing us to remove those or
   move the i2c_device_id table down to its more natural spot
   with the other module info.
 * It also checks for device match data, which allows for OF and
   ACPI based probing. That means we do not have to manually check
   those first and can remove those checks.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240403203633.914389-20-afd@ti.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

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 <u.kleine-koenig@pengutronix.de>
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 <linux@roeck-us.net>

We have bool so use it consistently in all the drivers.

The following Coccinelle script was used:

@@
identifier T;
type t = { char, int };
@@
struct T {
...
-	t valid;
+	bool valid;
...
}

@@
identifier v;
@@
(
- v->valid = 0
+ v->valid = false
|
- v->valid = 1
+ v->valid = true
)

followed by sed to fixup the comments:
sed '/bool valid;/{s/!=0/true/;s/zero/false/}'

Few whitespace changes were fixed manually. All modified drivers were
compile-tested.

Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Link: https://lore.kernel.org/r/20210924195202.27917-1-fercerpav@gmail.com
[groeck: Fixed up 'u8 valid' to 'boool valid' in atxp1.c]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

coccicheck complains about the use of snprintf() in sysfs
show functions.

drivers/hwmon/ina3221.c:701:8-16: WARNING: use scnprintf or sprintf

This results in a large number of patch submissions. Fix it all in
one go using the following coccinelle rules. Use sysfs_emit instead
of scnprintf or sprintf since that makes more sense.

@depends on patch@
identifier show, dev, attr, buf;
@@

ssize_t show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
  return
-		snprintf(buf, \( PAGE_SIZE \| PAGE_SIZE - 1 \),
+		sysfs_emit(buf,
		...);
	...>
}

@depends on patch@
identifier show, dev, attr, buf, rc;
@@

ssize_t show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
  rc =
-		snprintf(buf, \( PAGE_SIZE \| PAGE_SIZE - 1 \),
+		sysfs_emit(buf,
		...);
	...>
}

While at it, remove unnecessary braces and as well as unnecessary
else after return statements to address checkpatch warnings in the
resulting patch.

Cc: Zihao Tang <tangzihao1@hisilicon.com>
Cc: Jay Fang <f.fangjian@huawei.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

coccinelle complains about

WARNING opportunity for kobj_to_dev()

in several files, resulting in one-by-one patch submissions.
Handle all remaining instances in one go.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Many hwmon drivers don't use the id information provided by the old
i2c probe function, and the remainder can easily be adapted to the new
form ("probe_new") by calling i2c_match_id explicitly.

This avoids scanning the identifier tables during probes.

Drivers which didn't use the id are converted as-is; drivers which did
are modified as follows:

* if the information in i2c_client is sufficient, that's used instead
  (client->name);
* anything else is handled by calling i2c_match_id() with the same
  level of error-handling (if any) as before.

A few drivers aren't included in this patch because they have a
different set of maintainers. They will be covered by other patches.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20200813160222.1503401-1-steve@sk2.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>