From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Jacek Anaszewski <jacek.anaszewski@gmail.com>,
Pavel Machek <pavel@ucw.cz>, Dan Murphy <dmurphy@ti.com>
Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
Kees Cook <keescook@chromium.org>
Subject: [PATCH] leds: pwm: Use struct_size() helper
Date: Thu, 29 Aug 2019 19:53:20 -0500 [thread overview]
Message-ID: <20190830005320.GA15267@embeddedor> (raw)
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;
--
2.23.0
next reply other threads:[~2019-08-30 1:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-30 0:53 Gustavo A. R. Silva [this message]
2019-08-30 5:40 ` [PATCH] leds: pwm: Use struct_size() helper Kees Cook
2019-08-30 20:29 ` Jacek Anaszewski
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