* [PATCH] hwmon: lm80: fix a missing check of return value
@ 2018-12-21 6:13 Kangjie Lu
2018-12-21 14:43 ` Guenter Roeck
2019-01-02 15:23 ` Dan Carpenter
0 siblings, 2 replies; 4+ messages in thread
From: Kangjie Lu @ 2018-12-21 6:13 UTC (permalink / raw)
To: kjlu; +Cc: pakki001, Jean Delvare, Guenter Roeck, linux-hwmon, linux-kernel
If lm80_read_value() fails, it returns a negative number instead of the
correct read data. Therefore, we should avoid using the data if it
fails.
The fix checks if lm80_read_value() fails, and if so, returns with the
error number.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
drivers/hwmon/lm80.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/lm80.c b/drivers/hwmon/lm80.c
index 08e3945a6fbf..fca6363cd77f 100644
--- a/drivers/hwmon/lm80.c
+++ b/drivers/hwmon/lm80.c
@@ -360,9 +360,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
struct i2c_client *client = data->client;
unsigned long min, val;
u8 reg;
- int err = kstrtoul(buf, 10, &val);
- if (err < 0)
- return err;
+ int ret;
+
+ ret = kstrtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
/* Save fan_min */
mutex_lock(&data->update_lock);
@@ -390,8 +392,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
return -EINVAL;
}
- reg = (lm80_read_value(client, LM80_REG_FANDIV) &
- ~(3 << (2 * (nr + 1)))) | (data->fan_div[nr] << (2 * (nr + 1)));
+ ret = lm80_read_value(client, LM80_REG_FANDIV);
+ if (ret < 0)
+ return ret;
+ reg = (ret & ~(3 << (2 * (nr + 1))))
+ | (data->fan_div[nr] << (2 * (nr + 1)));
lm80_write_value(client, LM80_REG_FANDIV, reg);
/* Restore fan_min */
--
2.17.2 (Apple Git-113)
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] hwmon: lm80: fix a missing check of return value
2018-12-21 6:13 [PATCH] hwmon: lm80: fix a missing check of return value Kangjie Lu
@ 2018-12-21 14:43 ` Guenter Roeck
2019-01-02 15:23 ` Dan Carpenter
1 sibling, 0 replies; 4+ messages in thread
From: Guenter Roeck @ 2018-12-21 14:43 UTC (permalink / raw)
To: Kangjie Lu; +Cc: pakki001, Jean Delvare, linux-hwmon, linux-kernel
On 12/20/18 10:13 PM, Kangjie Lu wrote:
> If lm80_read_value() fails, it returns a negative number instead of the
> correct read data. Therefore, we should avoid using the data if it
> fails.
>
> The fix checks if lm80_read_value() fails, and if so, returns with the
> error number.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> drivers/hwmon/lm80.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/hwmon/lm80.c b/drivers/hwmon/lm80.c
> index 08e3945a6fbf..fca6363cd77f 100644
> --- a/drivers/hwmon/lm80.c
> +++ b/drivers/hwmon/lm80.c
> @@ -360,9 +360,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
> struct i2c_client *client = data->client;
> unsigned long min, val;
> u8 reg;
> - int err = kstrtoul(buf, 10, &val);
> - if (err < 0)
> - return err;
> + int ret;
> +
In the other patch you are using 'rv'. Please use consistent variable names.
Also, please use "hwmon: (lm80) <description>" as subject, and use different subjects
for both patches so we can distinguish them without looking into each patch itself.
This applies to the other patch as well.
Thanks,
Guenter
> + ret = kstrtoul(buf, 10, &val);
> + if (ret < 0)
> + return ret;
>
> /* Save fan_min */
> mutex_lock(&data->update_lock);
> @@ -390,8 +392,11 @@ static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
> return -EINVAL;
> }
>
> - reg = (lm80_read_value(client, LM80_REG_FANDIV) &
> - ~(3 << (2 * (nr + 1)))) | (data->fan_div[nr] << (2 * (nr + 1)));
> + ret = lm80_read_value(client, LM80_REG_FANDIV);
> + if (ret < 0)
> + return ret;
> + reg = (ret & ~(3 << (2 * (nr + 1))))
> + | (data->fan_div[nr] << (2 * (nr + 1)));
> lm80_write_value(client, LM80_REG_FANDIV, reg);
>
> /* Restore fan_min */
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] hwmon: lm80: fix a missing check of return value
2018-12-21 6:13 [PATCH] hwmon: lm80: fix a missing check of return value Kangjie Lu
2018-12-21 14:43 ` Guenter Roeck
@ 2019-01-02 15:23 ` Dan Carpenter
2019-01-02 16:17 ` Guenter Roeck
1 sibling, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2019-01-02 15:23 UTC (permalink / raw)
To: kbuild, Kangjie Lu
Cc: kbuild-all, kjlu, pakki001, Jean Delvare, Guenter Roeck,
linux-hwmon, linux-kernel
Hi Kangjie,
Thank you for the patch! Perhaps something to improve:
url: https://github.com/0day-ci/linux/commits/Kangjie-Lu/hwmon-lm80-fix-a-missing-check-of-return-value/20181222-023000
base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
smatch warnings:
drivers/hwmon/lm80.c:408 set_fan_div() warn: inconsistent returns 'mutex:&data->update_lock'.
Locked on: line 397
Unlocked on: line 367
# https://github.com/0day-ci/linux/commit/7612ba0bef1defb6de3290accca07633ccfd3365
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 7612ba0bef1defb6de3290accca07633ccfd3365
vim +408 drivers/hwmon/lm80.c
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 348
1160631b1 drivers/hwmon/lm80.c Guenter Roeck 2012-01-19 349 /*
1160631b1 drivers/hwmon/lm80.c Guenter Roeck 2012-01-19 350 * Note: we save and restore the fan minimum here, because its value is
1160631b1 drivers/hwmon/lm80.c Guenter Roeck 2012-01-19 351 * determined in part by the fan divisor. This follows the principle of
1160631b1 drivers/hwmon/lm80.c Guenter Roeck 2012-01-19 352 * least surprise; the user doesn't expect the fan minimum to change just
1160631b1 drivers/hwmon/lm80.c Guenter Roeck 2012-01-19 353 * because the divisor changed.
1160631b1 drivers/hwmon/lm80.c Guenter Roeck 2012-01-19 354 */
f8181762a drivers/hwmon/lm80.c Jean Delvare 2008-01-05 355 static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
f8181762a drivers/hwmon/lm80.c Jean Delvare 2008-01-05 356 const char *buf, size_t count)
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 357 {
f8181762a drivers/hwmon/lm80.c Jean Delvare 2008-01-05 358 int nr = to_sensor_dev_attr(attr)->index;
118c9a61f drivers/hwmon/lm80.c Guenter Roeck 2014-04-04 359 struct lm80_data *data = dev_get_drvdata(dev);
118c9a61f drivers/hwmon/lm80.c Guenter Roeck 2014-04-04 360 struct i2c_client *client = data->client;
6a9e7c4c0 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-10 361 unsigned long min, val;
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 362 u8 reg;
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 363 int ret;
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 364
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 365 ret = kstrtoul(buf, 10, &val);
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 366 if (ret < 0)
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 367 return ret;
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 368
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 369 /* Save fan_min */
9a61bf630 drivers/hwmon/lm80.c Ingo Molnar 2006-01-18 370 mutex_lock(&data->update_lock);
85b3ee07b drivers/hwmon/lm80.c Guenter Roeck 2014-04-13 371 min = FAN_FROM_REG(data->fan[f_min][nr],
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 372 DIV_FROM_REG(data->fan_div[nr]));
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 373
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 374 switch (val) {
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 375 case 1:
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 376 data->fan_div[nr] = 0;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 377 break;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 378 case 2:
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 379 data->fan_div[nr] = 1;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 380 break;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 381 case 4:
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 382 data->fan_div[nr] = 2;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 383 break;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 384 case 8:
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 385 data->fan_div[nr] = 3;
66b3b1f75 drivers/hwmon/lm80.c Frans Meulenbroeks 2012-01-04 386 break;
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 387 default:
118c9a61f drivers/hwmon/lm80.c Guenter Roeck 2014-04-04 388 dev_err(dev,
b55f37572 drivers/hwmon/lm80.c Guenter Roeck 2013-01-10 389 "fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
b55f37572 drivers/hwmon/lm80.c Guenter Roeck 2013-01-10 390 val);
9a61bf630 drivers/hwmon/lm80.c Ingo Molnar 2006-01-18 391 mutex_unlock(&data->update_lock);
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 392 return -EINVAL;
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 393 }
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 394
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 395 ret = lm80_read_value(client, LM80_REG_FANDIV);
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 396 if (ret < 0)
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 397 return ret;
^^^^^^^^^^
Need to drop the lock before returning.
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 398 reg = (ret & ~(3 << (2 * (nr + 1))))
7612ba0be drivers/hwmon/lm80.c Kangjie Lu 2018-12-21 399 | (data->fan_div[nr] << (2 * (nr + 1)));
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 400 lm80_write_value(client, LM80_REG_FANDIV, reg);
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 401
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 402 /* Restore fan_min */
85b3ee07b drivers/hwmon/lm80.c Guenter Roeck 2014-04-13 403 data->fan[f_min][nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
85b3ee07b drivers/hwmon/lm80.c Guenter Roeck 2014-04-13 404 lm80_write_value(client, LM80_REG_FAN_MIN(nr + 1),
85b3ee07b drivers/hwmon/lm80.c Guenter Roeck 2014-04-13 405 data->fan[f_min][nr]);
9a61bf630 drivers/hwmon/lm80.c Ingo Molnar 2006-01-18 406 mutex_unlock(&data->update_lock);
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 407
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 @408 return count;
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 409 }
^1da177e4 drivers/i2c/chips/lm80.c Linus Torvalds 2005-04-16 410
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] hwmon: lm80: fix a missing check of return value
2019-01-02 15:23 ` Dan Carpenter
@ 2019-01-02 16:17 ` Guenter Roeck
0 siblings, 0 replies; 4+ messages in thread
From: Guenter Roeck @ 2019-01-02 16:17 UTC (permalink / raw)
To: Dan Carpenter
Cc: kbuild, Kangjie Lu, kbuild-all, pakki001, Jean Delvare,
linux-hwmon, linux-kernel
On Wed, Jan 02, 2019 at 06:23:59PM +0300, Dan Carpenter wrote:
> Hi Kangjie,
>
> Thank you for the patch! Perhaps something to improve:
>
> url: https://github.com/0day-ci/linux/commits/Kangjie-Lu/hwmon-lm80-fix-a-missing-check-of-return-value/20181222-023000
> base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
>
Fix already queued, waiting for end of commit window.
Thanks,
Guenter
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-12-21 6:13 [PATCH] hwmon: lm80: fix a missing check of return value Kangjie Lu
2018-12-21 14:43 ` Guenter Roeck
2019-01-02 15:23 ` Dan Carpenter
2019-01-02 16:17 ` Guenter Roeck
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