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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-14 17:01:46 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2020-02-14 17:19:19 -0800 |
| commit | 3d87c75d84e20d8812dbfba87e46ffca29d75d40 (patch) | |
| tree | ffbe8d9d4626a8eafcbb1daad3a07502a8474baf /drivers/input | |
| parent | 5179a9dfa9440c1781816e2c9a183d1d2512dc61 (diff) | |
| download | linux-3d87c75d84e20d8812dbfba87e46ffca29d75d40.tar.bz2 | |
Input: gpio_keys_polled - 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>
Link: https://lore.kernel.org/r/20200214171907.GA26588@embeddedor
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/keyboard/gpio_keys_polled.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c index 6eb0a2f3f9de..c3937d2fc744 100644 --- a/drivers/input/keyboard/gpio_keys_polled.c +++ b/drivers/input/keyboard/gpio_keys_polled.c @@ -38,7 +38,7 @@ struct gpio_keys_polled_dev { const struct gpio_keys_platform_data *pdata; unsigned long rel_axis_seen[BITS_TO_LONGS(REL_CNT)]; unsigned long abs_axis_seen[BITS_TO_LONGS(ABS_CNT)]; - struct gpio_keys_button_data data[0]; + struct gpio_keys_button_data data[]; }; static void gpio_keys_button_event(struct input_dev *input, |