diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-19 16:51:46 -0500 |
|---|---|---|
| committer | Pavel Machek <pavel@ucw.cz> | 2020-03-21 16:21:16 +0100 |
| commit | 7bbec6c4b51d2323459203510028e8344f79e126 (patch) | |
| tree | a8469af33d0d703601a2ee61a427ad338fe3317b /drivers/leds | |
| parent | 7a630367759869612a3a7aec76cff4b436b7f9aa (diff) | |
leds: leds-pwm: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/leds-pwm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index 6caf8bea8cd5..6c8a724aac51 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -39,7 +39,7 @@ struct led_pwm_data { struct led_pwm_priv { int num_leds; - struct led_pwm_data leds[0]; + struct led_pwm_data leds[]; }; static int led_pwm_set(struct led_classdev *led_cdev, |