From a5bf6fdd19c327bcfd9073a8740fa19ca4525fd4 Mon Sep 17 00:00:00 2001
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Date: Sun, 17 May 2020 18:29:59 +0100
Subject: [PATCH] iio:chemical:sps30: Fix timestamp alignment
Git-commit: a5bf6fdd19c327bcfd9073a8740fa19ca4525fd4
Patch-mainline: v5.8-rc1
References: git-fixes

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.

Fixes: 232e0f6ddeae ("iio: chemical: add support for Sensirion SPS30 sensor")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: <Stable@vger.kernel.org>
Acked-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/iio/chemical/sps30.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/chemical/sps30.c b/drivers/iio/chemical/sps30.c
index acb9f8ecbb3d..a88c1fb875a0 100644
--- a/drivers/iio/chemical/sps30.c
+++ b/drivers/iio/chemical/sps30.c
@@ -230,15 +230,18 @@ static irqreturn_t sps30_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct sps30_state *state = iio_priv(indio_dev);
 	int ret;
-	s32 data[4 + 2]; /* PM1, PM2P5, PM4, PM10, timestamp */
+	struct {
+		s32 data[4]; /* PM1, PM2P5, PM4, PM10 */
+		s64 ts;
+	} scan;
 
 	mutex_lock(&state->lock);
-	ret = sps30_do_meas(state, data, 4);
+	ret = sps30_do_meas(state, scan.data, ARRAY_SIZE(scan.data));
 	mutex_unlock(&state->lock);
 	if (ret)
 		goto err;
 
-	iio_push_to_buffers_with_timestamp(indio_dev, data,
+	iio_push_to_buffers_with_timestamp(indio_dev, &scan,
 					   iio_get_time_ns(indio_dev));
 err:
 	iio_trigger_notify_done(indio_dev->trig);
-- 
2.16.4