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| author | Arnd Bergmann <arnd@arndb.de> | 2016-10-24 17:22:01 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-02-23 03:50:55 +0000 |
| commit | b9b469ede23f215cb34a825a9c55d8b55dfc0a3f (patch) | |
| tree | 54defad9eabaecf3fed73e61e2c80a10b1be9cc1 /drivers | |
| parent | a0228da004e96c3569466e19d13c920d9f61e79b (diff) | |
| download | linux-b9b469ede23f215cb34a825a9c55d8b55dfc0a3f.tar.gz linux-b9b469ede23f215cb34a825a9c55d8b55dfc0a3f.tar.bz2 linux-b9b469ede23f215cb34a825a9c55d8b55dfc0a3f.zip | |
staging: iio: ad5933: avoid uninitialized variable in error case
commit 34eee70a7b82b09dbda4cb453e0e21d460dae226 upstream.
The ad5933_i2c_read function returns an error code to indicate
whether it could read data or not. However ad5933_work() ignores
this return code and just accesses the data unconditionally,
which gets detected by gcc as a possible bug:
drivers/staging/iio/impedance-analyzer/ad5933.c: In function 'ad5933_work':
drivers/staging/iio/impedance-analyzer/ad5933.c:649:16: warning: 'status' may be used uninitialized in this function [-Wmaybe-uninitialized]
This adds minimal error handling so we only evaluate the
data if it was correctly read.
Link: https://patchwork.kernel.org/patch/8110281/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/iio/impedance-analyzer/ad5933.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c index b8819de1cd8a..1ce569a405b2 100644 --- a/drivers/staging/iio/impedance-analyzer/ad5933.c +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c @@ -626,6 +626,7 @@ static void ad5933_work(struct work_struct *work) struct iio_buffer *ring = indio_dev->buffer; signed short buf[2]; unsigned char status; + int ret; mutex_lock(&indio_dev->mlock); if (st->state == AD5933_CTRL_INIT_START_FREQ) { @@ -633,17 +634,20 @@ static void ad5933_work(struct work_struct *work) ad5933_cmd(st, AD5933_CTRL_START_SWEEP); st->state = AD5933_CTRL_START_SWEEP; schedule_delayed_work(&st->work, st->poll_time_jiffies); - mutex_unlock(&indio_dev->mlock); - return; + goto out; } - ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status); + ret = ad5933_i2c_read(st->client, AD5933_REG_STATUS, 1, &status); + if (ret) + goto out; if (status & AD5933_STAT_DATA_VALID) { - ad5933_i2c_read(st->client, + ret = ad5933_i2c_read(st->client, test_bit(1, ring->scan_mask) ? AD5933_REG_REAL_DATA : AD5933_REG_IMAG_DATA, ring->scan_count * 2, (u8 *)buf); + if (ret) + goto out; if (ring->scan_count == 2) { buf[0] = be16_to_cpu(buf[0]); @@ -656,8 +660,7 @@ static void ad5933_work(struct work_struct *work) } else { /* no data available - try again later */ schedule_delayed_work(&st->work, st->poll_time_jiffies); - mutex_unlock(&indio_dev->mlock); - return; + goto out; } if (status & AD5933_STAT_SWEEP_DONE) { @@ -669,7 +672,7 @@ static void ad5933_work(struct work_struct *work) ad5933_cmd(st, AD5933_CTRL_INC_FREQ); schedule_delayed_work(&st->work, st->poll_time_jiffies); } - +out: mutex_unlock(&indio_dev->mlock); } |