From: Dmitry Osipenko <digetx@gmail.com>
To: Zhang Rui <rui.zhang@intel.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Amit Kucheria <amitk@kernel.org>,
Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org, linux-pm@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: [PATCH v3 1/2] hwmon: (lm90) Prevent integer underflows of temperature calculations
Date: Mon, 21 Jun 2021 21:40:57 +0300 [thread overview]
Message-ID: <20210621184058.4110-2-digetx@gmail.com> (raw)
In-Reply-To: <20210621184058.4110-1-digetx@gmail.com>
The min/max/crit and all other temperature values that are passed to
the driver are unlimited and value that is close to INT_MIN results in
integer underflow of the temperature calculations made by the driver
for LM99 sensor. Temperature hysteresis is among those values that need
to be limited, but limiting of hysteresis is independent from the sensor
version. Add the missing limits.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/hwmon/lm90.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index b53f17511b05..ee6b8190f08e 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1028,6 +1028,9 @@ static int lm90_set_temp11(struct lm90_data *data, int index, long val)
struct reg *regp = ®[index];
int err;
+ /* prevent integer underflow */
+ val = max(val, -128000l);
+
/* +16 degrees offset for temp2 for the LM99 */
if (data->kind == lm99 && index <= 2)
val -= 16000;
@@ -1088,6 +1091,9 @@ static int lm90_set_temp8(struct lm90_data *data, int index, long val)
struct i2c_client *client = data->client;
int err;
+ /* prevent integer underflow */
+ val = max(val, -128000l);
+
/* +16 degrees offset for temp2 for the LM99 */
if (data->kind == lm99 && index == 3)
val -= 16000;
@@ -1130,6 +1136,9 @@ static int lm90_set_temphyst(struct lm90_data *data, long val)
int temp;
int err;
+ /* prevent integer underflow */
+ val = max(val, -128000l);
+
if (data->kind == adt7461 || data->kind == tmp451)
temp = temp_from_u8_adt7461(data, data->temp8[LOCAL_CRIT]);
else if (data->kind == max6646)
--
2.30.2
next prev parent reply other threads:[~2021-06-21 18:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-21 18:40 [PATCH v3 0/2] Support temperature trips by HWMON core and LM90 driver Dmitry Osipenko
2021-06-21 18:40 ` Dmitry Osipenko [this message]
2021-06-21 18:40 ` [PATCH v3 2/2] hwmon: Support set_trips() of thermal device ops Dmitry Osipenko
2021-06-21 20:30 ` Guenter Roeck
2021-06-21 20:45 ` Dmitry Osipenko
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