[PATCH v2] iio: irsd200: fix -Warray-bounds bug in irsd200_trigger_handler

[GONG, Ruiqi]

From: "GONG, Ruiqi" <gongruiqi1@xxxxxxxxxx>

When compiling with gcc 13 with -Warray-bounds enabled:

In file included from drivers/iio/proximity/irsd200.c:15:
In function ‘iio_push_to_buffers_with_timestamp’,
    inlined from ‘irsd200_trigger_handler’ at drivers/iio/proximity/irsd200.c:770:2:
./include/linux/iio/buffer.h:42:46: error: array subscript ‘int64_t {aka long long int}[0]’
is partly outside array bounds of ‘s16[1]’ {aka ‘short int[1]’} [-Werror=array-bounds=]
   42 |                 ((int64_t *)data)[ts_offset] = timestamp;
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
drivers/iio/proximity/irsd200.c: In function ‘irsd200_trigger_handler’:
drivers/iio/proximity/irsd200.c:763:13: note: object ‘buf’ of size 2
  763 |         s16 buf = 0;
      |             ^~~

The problem seems to be that irsd200_trigger_handler() is taking a s16
variable as an int64_t buffer. As Jonathan suggested [1], fix it by
extending the buffer to a two-element array of s64.

Link: https://github.com/KSPP/linux/issues/331
Link: https://lore.kernel.org/lkml/20230809181329.46c00a5d@jic23-huawei/ [1]
Fixes: 3db3562bc66e ("iio: Add driver for Murata IRS-D200")
Signed-off-by: GONG, Ruiqi <gongruiqi1@xxxxxxxxxx>
Acked-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---

v2: change buf to `s64 buf[2]`

 drivers/iio/proximity/irsd200.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/proximity/irsd200.c b/drivers/iio/proximity/irsd200.c
index 5bd791b46d98..bdff91f6b1a3 100644
--- a/drivers/iio/proximity/irsd200.c
+++ b/drivers/iio/proximity/irsd200.c
@@ -759,14 +759,14 @@ static irqreturn_t irsd200_trigger_handler(int irq, void *pollf)
 {
 	struct iio_dev *indio_dev = ((struct iio_poll_func *)pollf)->indio_dev;
 	struct irsd200_data *data = iio_priv(indio_dev);
-	s16 buf = 0;
+	s64 buf[2] = {};
 	int ret;
 
-	ret = irsd200_read_data(data, &buf);
+	ret = irsd200_read_data(data, (s16 *)buf);
 	if (ret)
 		goto end;
 
-	iio_push_to_buffers_with_timestamp(indio_dev, &buf,
+	iio_push_to_buffers_with_timestamp(indio_dev, buf,
 					   iio_get_time_ns(indio_dev));
 
 end:
-- 
2.41.0