From 8db4afe163bbdd93dca6fcefbb831ef12ecc6b4d Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Sun, 7 Jun 2020 16:53:57 +0100 Subject: iio:pressure:ms5611 Fix buffer element alignment One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses an array of smaller elements on the stack. Here there is no data leak possibility so use an explicit structure on the stack to ensure alignment and nice readable fashion. The forced alignment of ts isn't strictly necessary in this driver as the padding will be correct anyway (there isn't any). However it is probably less fragile to have it there and it acts as documentation of the requirement. Fixes: 713bbb4efb9dc ("iio: pressure: ms5611: Add triggered buffer support") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Acked-by: Tomasz Duszynski Cc: --- drivers/iio/pressure/ms5611_core.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/iio/pressure') diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c index 2f598ad91621..f5db9fa086f3 100644 --- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -212,16 +212,21 @@ static irqreturn_t ms5611_trigger_handler(int irq, void *p) struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct ms5611_state *st = iio_priv(indio_dev); - s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */ + /* Ensure buffer elements are naturally aligned */ + struct { + s32 channels[2]; + s64 ts __aligned(8); + } scan; int ret; mutex_lock(&st->lock); - ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]); + ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1], + &scan.channels[0]); mutex_unlock(&st->lock); if (ret < 0) goto err; - iio_push_to_buffers_with_timestamp(indio_dev, buf, + iio_push_to_buffers_with_timestamp(indio_dev, &scan, iio_get_time_ns(indio_dev)); err: -- cgit v1.2.3