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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-14 17:02:11 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2020-02-14 17:19:21 -0800 |
| commit | 94bef5d57992f9e987a9b7e8fa736ee204ac4f7a (patch) | |
| tree | 0688424e5af23a6c11691cff0f55d3c51770cbeb | |
| parent | 3d87c75d84e20d8812dbfba87e46ffca29d75d40 (diff) | |
| download | linux-94bef5d57992f9e987a9b7e8fa736ee204ac4f7a.tar.bz2 | |
Input: tca6416-keypad - 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/20200214172022.GA27490@embeddedor
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
| -rw-r--r-- | drivers/input/keyboard/tca6416-keypad.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c index 2a14769de637..21758767ccf0 100644 --- a/drivers/input/keyboard/tca6416-keypad.c +++ b/drivers/input/keyboard/tca6416-keypad.c @@ -33,7 +33,7 @@ MODULE_DEVICE_TABLE(i2c, tca6416_id); struct tca6416_drv_data { struct input_dev *input; - struct tca6416_button data[0]; + struct tca6416_button data[]; }; struct tca6416_keypad_chip { @@ -48,7 +48,7 @@ struct tca6416_keypad_chip { int irqnum; u16 pinmask; bool use_polling; - struct tca6416_button buttons[0]; + struct tca6416_button buttons[]; }; static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val) |