From: trix@redhat.com
To: rydberg@bitmath.org, jdelvare@suse.com, linux@roeck-us.net
Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org,
Tom Rix <trix@redhat.com>
Subject: [PATCH] hwmon: applesmc: check status earlier.
Date: Thu, 20 Aug 2020 06:19:32 -0700 [thread overview]
Message-ID: <20200820131932.10590-1-trix@redhat.com> (raw)
From: Tom Rix <trix@redhat.com>
clang static analysis reports this representative problem
applesmc.c:758:10: warning: 1st function call argument is an
uninitialized value
left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
buffer is filled by the earlier call
ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, ...
This problem is reported because a goto skips the status check.
Other similar problems use data from applesmc_read_key before checking
the status. So move the checks to before the use.
Signed-off-by: Tom Rix <trix@redhat.com>
---
drivers/hwmon/applesmc.c | 31 ++++++++++++++++---------------
1 file changed, 16 insertions(+), 15 deletions(-)
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index 316618409315..a18887990f4a 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -753,15 +753,18 @@ static ssize_t applesmc_light_show(struct device *dev,
}
ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, buffer, data_length);
+ if (ret)
+ goto out;
/* newer macbooks report a single 10-bit bigendian value */
if (data_length == 10) {
left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2;
goto out;
}
left = buffer[2];
+
+ ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, data_length);
if (ret)
goto out;
- ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, data_length);
right = buffer[2];
out:
@@ -810,12 +813,11 @@ static ssize_t applesmc_show_fan_speed(struct device *dev,
to_index(attr));
ret = applesmc_read_key(newkey, buffer, 2);
- speed = ((buffer[0] << 8 | buffer[1]) >> 2);
-
if (ret)
return ret;
- else
- return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", speed);
+
+ speed = ((buffer[0] << 8 | buffer[1]) >> 2);
+ return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", speed);
}
static ssize_t applesmc_store_fan_speed(struct device *dev,
@@ -851,12 +853,11 @@ static ssize_t applesmc_show_fan_manual(struct device *dev,
u8 buffer[2];
ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
- manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01;
-
if (ret)
return ret;
- else
- return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", manual);
+
+ manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01;
+ return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", manual);
}
static ssize_t applesmc_store_fan_manual(struct device *dev,
@@ -872,10 +873,11 @@ static ssize_t applesmc_store_fan_manual(struct device *dev,
return -EINVAL;
ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
- val = (buffer[0] << 8 | buffer[1]);
if (ret)
goto out;
+ val = (buffer[0] << 8 | buffer[1]);
+
if (input)
val = val | (0x01 << to_index(attr));
else
@@ -951,13 +953,12 @@ static ssize_t applesmc_key_count_show(struct device *dev,
u32 count;
ret = applesmc_read_key(KEY_COUNT_KEY, buffer, 4);
- count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) +
- ((u32)buffer[2]<<8) + buffer[3];
-
if (ret)
return ret;
- else
- return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", count);
+
+ count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) +
+ ((u32)buffer[2]<<8) + buffer[3];
+ return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", count);
}
static ssize_t applesmc_key_at_index_read_show(struct device *dev,
--
2.18.1
next reply other threads:[~2020-08-20 13:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-20 13:19 trix [this message]
2020-08-20 20:57 ` [PATCH] hwmon: applesmc: check status earlier Henrik Rydberg
2020-08-21 18:33 ` Guenter Roeck
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