diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-17 13:58:16 -0600 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-02-17 19:05:05 -0800 |
commit | dc3cc347d2ce77da41f120a6162b40c6139df754 (patch) | |
tree | 7039eb6880c9d1a0c351db44efc29efd0329c567 /drivers | |
parent | 725d23b59cd18074f0bdc1ce94d71e3d734adab6 (diff) |
net: usb: cdc-phonet: 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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/usb/cdc-phonet.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/usb/cdc-phonet.c b/drivers/net/usb/cdc-phonet.c index bcabd39d136a..9bdbd7b472a0 100644 --- a/drivers/net/usb/cdc-phonet.c +++ b/drivers/net/usb/cdc-phonet.c @@ -36,7 +36,7 @@ struct usbpn_dev { spinlock_t rx_lock; struct sk_buff *rx_skb; - struct urb *urbs[0]; + struct urb *urbs[]; }; static void tx_complete(struct urb *req); |