diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-20 00:51:12 +0300 |
|---|---|---|
| committer | Pavel Machek <pavel@ucw.cz> | 2020-03-21 18:21:16 +0300 |
| commit | 7a630367759869612a3a7aec76cff4b436b7f9aa (patch) | |
| tree | 4230f2ffabd58ad76e9903ec00997436b6ef4255 | |
| parent | 4227685b4dda61a3c0d2f10d50d364cb9c1a669d (diff) | |
| download | linux-7a630367759869612a3a7aec76cff4b436b7f9aa.tar.xz | |
leds: leds-is31fl32xx: 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>
| -rw-r--r-- | drivers/leds/leds-is31fl32xx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/leds/leds-is31fl32xx.c b/drivers/leds/leds-is31fl32xx.c index 6f29b8943913..cd768f991da1 100644 --- a/drivers/leds/leds-is31fl32xx.c +++ b/drivers/leds/leds-is31fl32xx.c @@ -44,7 +44,7 @@ struct is31fl32xx_priv { const struct is31fl32xx_chipdef *cdef; struct i2c_client *client; unsigned int num_leds; - struct is31fl32xx_led_data leds[0]; + struct is31fl32xx_led_data leds[]; }; /** |