From: Jonathan Cameron Jonathan.Cameron@huawei.com
commit 198cf32f0503d2ad60d320b95ef6fb8243db857f upstream.
Whilst this is another case of the issue Lars reported with an array of elements of smaller than 8 bytes being passed to iio_push_to_buffers_with_timestamp(), the solution here is a bit different from the other cases and relies on __aligned working on the stack (true since 4.6?)
This one is unusual. We have to do an explicit memset() each time as we are reading 3 bytes into a potential 4 byte channel which may sometimes be a 2 byte channel depending on what is enabled. As such, moving the buffer to the heap in the iio_priv structure doesn't save us much. We can't use a nice explicit structure on the stack either as the data channels have different storage sizes and are all separately controlled.
Fixes: cc26ad455f57 ("iio: Add Freescale MPL3115A2 pressure / temperature sensor driver") Reported-by: Lars-Peter Clausen lars@metafoo.de Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Reviewed-by: Alexandru Ardelean alexandru.ardelean@analog.com Cc: Peter Meerwald pmeerw@pmeerw.net Cc: Stable@vger.kernel.org Link: https://lore.kernel.org/r/20200920112742.170751-7-jic23@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iio/pressure/mpl3115.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/iio/pressure/mpl3115.c +++ b/drivers/iio/pressure/mpl3115.c @@ -144,7 +144,14 @@ static irqreturn_t mpl3115_trigger_handl struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct mpl3115_data *data = iio_priv(indio_dev); - u8 buffer[16]; /* 32-bit channel + 16-bit channel + padding + ts */ + /* + * 32-bit channel + 16-bit channel + padding + ts + * Note that it is possible for only one of the first 2 + * channels to be enabled. If that happens, the first element + * of the buffer may be either 16 or 32-bits. As such we cannot + * use a simple structure definition to express this data layout. + */ + u8 buffer[16] __aligned(8); int ret, pos = 0;
mutex_lock(&data->lock);