The snprintf() function returns the number of characters which would
have been printed if there were enough space, but the scnprintf()
returns the number of characters which were actually printed. If the
buffer is not large enough, then using snprintf() would result in a
read overflow and an information leak.
Fixes: 8910c0bd53 ("hwmon: (pmbus/max20730) add device monitoring via debugfs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20201022070824.GC2817762@mwanda
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Problem:
We use voltage dividers so that the voltage presented at the voltage
sense pins is confusing. We might need to convert these readings to more
meaningful readings given the voltage divider.
Solution:
Read the voltage divider resistance from dts and convert the voltage
reading to a more meaningful reading.
Testing:
max20730 with voltage divider
Signed-off-by: Chu Lin <linchuyuan@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201004031445.2321090-3-linchuyuan@google.com
[groeck: Return -EINVAL instead of -ENODEV on bad deevicetree data]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
pmbus_do_probe doesn't use the id information provided in its second
argument, so this can be removed, which then allows using the
single-parameter i2c probe function ("probe_new") for probes.
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);
* configured v. probed comparisons are performed by comparing the
configured name to the detected name, instead of the ids; this
involves strcmp but is still cheaper than comparing all the device
names when scanning the tables;
* anything else is handled by calling i2c_match_id() with the same
level of error-handling (if any) as before.
Additionally, the mismatch message in the ltc2978 driver is adjusted
so that it no longer assumes that the driver_data is an index into
ltc2978_id.
Signed-off-by: Stephen Kitt <steve@sk2.org>
Acked-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20200808210004.30880-1-steve@sk2.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
In preparation for multi-phase support, add 'phase' parameter to read_word
and set_page functions. Actual multi-phase support will be added in
a subsequent patch.
Cc: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
