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authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-03-19 16:51:46 -0500
committerPavel Machek <pavel@ucw.cz>2020-03-21 16:21:16 +0100
commit7bbec6c4b51d2323459203510028e8344f79e126 (patch)
treea8469af33d0d703601a2ee61a427ad338fe3317b /drivers/leds
parent7a630367759869612a3a7aec76cff4b436b7f9aa (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.c2
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,