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authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-02-14 17:02:11 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2020-02-14 17:19:21 -0800
commit94bef5d57992f9e987a9b7e8fa736ee204ac4f7a (patch)
tree0688424e5af23a6c11691cff0f55d3c51770cbeb
parent3d87c75d84e20d8812dbfba87e46ffca29d75d40 (diff)
downloadlinux-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.c4
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)