linux-kernel - [PATCH 01/10] iio: accel: sca3300: use struct with aligned

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250418-iio-prefer-aligned_s64-timestamp-v1-1-4c6080710516@baylibre.com>
Date: Fri, 18 Apr 2025 14:58:20 -0500
From: David Lechner <dlechner@...libre.com>
To: Jonathan Cameron <jic23@...nel.org>, 
 Nuno Sá <nuno.sa@...log.com>, 
 Andy Shevchenko <andy@...nel.org>, Eugen Hristev <eugen.hristev@...aro.org>, 
 Nicolas Ferre <nicolas.ferre@...rochip.com>, 
 Alexandre Belloni <alexandre.belloni@...tlin.com>, 
 Claudiu Beznea <claudiu.beznea@...on.dev>, 
 Andreas Klinger <ak@...klinger.de>, Shawn Guo <shawnguo@...nel.org>, 
 Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, 
 Maxime Coquelin <mcoquelin.stm32@...il.com>, 
 Alexandre Torgue <alexandre.torgue@...s.st.com>
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, imx@...ts.linux.dev, 
 linux-stm32@...md-mailman.stormreply.com, 
 David Lechner <dlechner@...libre.com>
Subject: [PATCH 01/10] iio: accel: sca3300: use struct with aligned_s64
 timestamp

Use a struct with aligned_s64 timestamp instead of a padded array for
the buffer used for iio_push_to_buffers_with_ts(). This makes it easier
to see the correctness of the size and alignment of the buffer.

Changing the array part to s16 insted of u8 also lets us drop the cast
when it is used.

Signed-off-by: David Lechner <dlechner@...libre.com>
---
 drivers/iio/accel/sca3300.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index 1132bbaba75bcca525fac2f3e19f63546380fd4f..f04ad523f48abd598b1b2df37c51da894c0ce796 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -58,15 +58,6 @@ enum sca3300_scan_indexes {
 	SCA3300_SCAN_MAX
 };
 
-/*
- * Buffer size max case:
- * Three accel channels, two bytes per channel.
- * Temperature channel, two bytes.
- * Three incli channels, two bytes per channel.
- * Timestamp channel, eight bytes.
- */
-#define SCA3300_MAX_BUFFER_SIZE (ALIGN(sizeof(s16) * SCA3300_SCAN_MAX, sizeof(s64)) + sizeof(s64))
-
 #define SCA3300_ACCEL_CHANNEL(index, reg, axis) {			\
 	.type = IIO_ACCEL,						\
 	.address = reg,							\
@@ -203,7 +194,10 @@ struct sca3300_data {
 	struct spi_device *spi;
 	struct mutex lock;
 	const struct sca3300_chip_info *chip;
-	u8 buffer[SCA3300_MAX_BUFFER_SIZE] __aligned(sizeof(s64));
+	struct {
+		s16 channels[SCA3300_SCAN_MAX];
+		aligned_s64 timestamp;
+	} buffer;
 	u8 txbuf[4] __aligned(IIO_DMA_MINALIGN);
 	u8 rxbuf[4];
 };
@@ -492,7 +486,7 @@ static irqreturn_t sca3300_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct sca3300_data *data = iio_priv(indio_dev);
 	int bit, ret, val, i = 0;
-	s16 *channels = (s16 *)data->buffer;
+	s16 *channels = data->buffer.channels;
 
 	iio_for_each_active_channel(indio_dev, bit) {
 		ret = sca3300_read_reg(data, indio_dev->channels[bit].address, &val);
@@ -505,7 +499,7 @@ static irqreturn_t sca3300_trigger_handler(int irq, void *p)
 		channels[i++] = val;
 	}
 
-	iio_push_to_buffers_with_ts(indio_dev, data->buffer,
+	iio_push_to_buffers_with_ts(indio_dev, &data->buffer,
 				    sizeof(data->buffer),
 				    iio_get_time_ns(indio_dev));
 out:

-- 
2.43.0