Received-SPF: pass (google.com: domain of linux-kernel+bounces-90918-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Message-ID: <cb286926-3ebe-4ff3-926e-df9dfe215fda@embeddedor.com>
Date: Mon, 4 Mar 2024 10:16:05 -0600
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v2 2/3] spi: axi-spi-engine: use __counted_by() attribute
Content-Language: en-US
To: David Lechner <dlechner@baylibre.com>, Mark Brown <broonie@kernel.org>
Cc: Michael Hennerich <michael.hennerich@analog.com>,
 =?UTF-8?Q?Nuno_S=C3=A1?= <nuno.sa@analog.com>,
 Kees Cook <keescook@chromium.org>,
 "Gustavo A. R. Silva" <gustavoars@kernel.org>, linux-spi@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
References: <20240304-mainline-axi-spi-engine-small-cleanups-v2-0-5b14ed729a31@baylibre.com>
 <20240304-mainline-axi-spi-engine-small-cleanups-v2-2-5b14ed729a31@baylibre.com>
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20240304-mainline-axi-spi-engine-small-cleanups-v2-2-5b14ed729a31@baylibre.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit


On 04/03/24 10:04, 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>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
--
Gustavo

> ---
> v2 changes:
> * Reordered assignment of length field.
> ---
>   drivers/spi/spi-axi-spi-engine.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> 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)
>