From: Jacek Anaszewski <jacek.anaszewski@gmail.com>
To: "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
Pavel Machek <pavel@ucw.cz>, Dan Murphy <dmurphy@ti.com>
Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH] leds: pwm: Use struct_size() helper
Date: Fri, 30 Aug 2019 22:29:12 +0200 [thread overview]
Message-ID: <2d60cc38-a594-4457-6fb0-64ec96af477e@gmail.com> (raw)
In-Reply-To: <20190830005320.GA15267@embeddedor>
Hi Gustavo,
Thank you for the patch.
On 8/30/19 2:53 AM, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
>
> struct led_pwm_priv {
> ...
> struct led_pwm_data leds[0];
> };
>
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes.
>
> So, replace the following function:
>
> static inline size_t sizeof_pwm_leds_priv(int num_leds)
> {
> return sizeof(struct led_pwm_priv) +
> (sizeof(struct led_pwm_data) * num_leds);
> }
>
> with:
>
> struct_size(priv, leds, count)
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> drivers/leds/leds-pwm.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
> index d0e1f2710351..8b6965a563e9 100644
> --- a/drivers/leds/leds-pwm.c
> +++ b/drivers/leds/leds-pwm.c
> @@ -65,12 +65,6 @@ static int led_pwm_set(struct led_classdev *led_cdev,
> return 0;
> }
>
> -static inline size_t sizeof_pwm_leds_priv(int num_leds)
> -{
> - return sizeof(struct led_pwm_priv) +
> - (sizeof(struct led_pwm_data) * num_leds);
> -}
> -
> static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
> struct led_pwm *led, struct fwnode_handle *fwnode)
> {
> @@ -174,7 +168,7 @@ static int led_pwm_probe(struct platform_device *pdev)
> if (!count)
> return -EINVAL;
>
> - priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
> + priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count),
> GFP_KERNEL);
> if (!priv)
> return -ENOMEM;
>
Applied.
--
Best regards,
Jacek Anaszewski
prev parent reply other threads:[~2019-08-30 20:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-30 0:53 [PATCH] leds: pwm: Use struct_size() helper Gustavo A. R. Silva
2019-08-30 5:40 ` Kees Cook
2019-08-30 20:29 ` Jacek Anaszewski [this message]
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