diff mbox series

[v2,2/3] spi: axi-spi-engine: use __counted_by() attribute

Message ID 20240304-mainline-axi-spi-engine-small-cleanups-v2-2-5b14ed729a31@baylibre.com
State New
Headers
Series spi: axi-spi-engine: small cleanups |

Commit Message

David Lechner March 4, 2024, 4:04 p.m. UTC 
  This adds the __counted_by() attribute to the flex array at the end of
struct spi_engine_program in the AXI SPI Engine controller driver.

The assignment of the length field has to be reordered to be before
the access to the flex array in order to avoid potential compiler
warnings/errors due to adding the __counted_by() attribute.

Suggested-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: David Lechner <dlechner@baylibre.com>
---
v2 changes:
* Reordered assignment of length field.
---
 drivers/spi/spi-axi-spi-engine.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Comments

Kees Cook March 4, 2024, 5:36 p.m. UTC | #1 
On Mon, Mar 04, 2024 at 10:04:24AM -0600, David Lechner wrote:
> This adds the __counted_by() attribute to the flex array at the end of
> struct spi_engine_program in the AXI SPI Engine controller driver.
> 
> The assignment of the length field has to be reordered to be before
> the access to the flex array in order to avoid potential compiler
> warnings/errors due to adding the __counted_by() attribute.
> 
> Suggested-by: Nuno Sá <nuno.sa@analog.com>
> Signed-off-by: David Lechner <dlechner@baylibre.com>

Looks good! Thanks for the respin.

Reviewed-by: Kees Cook <keescook@chromium.org>
diff mbox series

Patch

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index d89f75170c9e..a8f626165f44 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -75,7 +75,7 @@ 
 
 struct spi_engine_program {
 	unsigned int length;
-	uint16_t instructions[];
+	uint16_t instructions[] __counted_by(length);
 };
 
 /**
@@ -115,9 +115,10 @@  struct spi_engine {
 static void spi_engine_program_add_cmd(struct spi_engine_program *p,
 	bool dry, uint16_t cmd)
 {
-	if (!dry)
-		p->instructions[p->length] = cmd;
 	p->length++;
+
+	if (!dry)
+		p->instructions[p->length - 1] = cmd;
 }
 
 static unsigned int spi_engine_get_config(struct spi_device *spi)