From: Tom Rix trix@redhat.com
[ Upstream commit cecf7560f00a8419396a2ed0f6e5d245ccb4feac ]
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 Reviewed-by: Henrik Rydberg rydberg@bitmath.org Link: https://lore.kernel.org/r/20200820131932.10590-1-trix@redhat.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5c677ba440143..b201129a9beae 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -760,15 +760,18 @@ 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: @@ -817,12 +820,11 @@ 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, @@ -858,12 +860,11 @@ 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, @@ -879,10 +880,11 @@ 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 @@ -958,13 +960,12 @@ 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,