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authorGustavo A. R. Silva <gustavo@embeddedor.com>2020-02-14 17:01:46 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2020-02-14 17:19:19 -0800
commit3d87c75d84e20d8812dbfba87e46ffca29d75d40 (patch)
treeffbe8d9d4626a8eafcbb1daad3a07502a8474baf /drivers/input
parent5179a9dfa9440c1781816e2c9a183d1d2512dc61 (diff)
downloadlinux-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.c2
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,