diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-12 13:30:19 -0600 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2020-02-13 08:28:38 +0100 |
| commit | c920a191302e3a4b3a98aeabce37d715fdf5cea5 (patch) | |
| tree | 668a88905274e0c3c02f31b2cb6494cb54ca4816 | |
| parent | 7c36948329cdb986ef3596a13e2383dbb50ded80 (diff) | |
Bluetooth: hci_uart: 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
inadvertenly 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: Marcel Holtmann <marcel@holtmann.org>
| -rw-r--r-- | drivers/bluetooth/hci_ag6xx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/bluetooth/hci_ag6xx.c b/drivers/bluetooth/hci_ag6xx.c index 8bafa650b5b0..1f55df93e4ce 100644 --- a/drivers/bluetooth/hci_ag6xx.c +++ b/drivers/bluetooth/hci_ag6xx.c @@ -27,7 +27,7 @@ struct ag6xx_data { struct pbn_entry { __le32 addr; __le32 plen; - __u8 data[0]; + __u8 data[]; } __packed; static int ag6xx_open(struct hci_uart *hu) |