diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-28 16:59:59 +0300 |
|---|---|---|
| committer | Stefan Schmidt <stefan@datenfreihafen.org> | 2020-02-29 16:39:08 +0300 |
| commit | 53cb2cfaa62d122fa9d92398926a6b7e8f052844 (patch) | |
| tree | adc6f8283fd6ca8a1d1330890763f2568f491e90 /include/net/cfg802154.h | |
| parent | 5b5c328f63fd61cce313ae105d32e7f532db0737 (diff) | |
| download | linux-53cb2cfaa62d122fa9d92398926a6b7e8f052844.tar.xz | |
cfg802154: 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: Stefan Schmidt <stefan@datenfreihafen.org>
Diffstat (limited to 'include/net/cfg802154.h')
| -rw-r--r-- | include/net/cfg802154.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h index 6f86073a5d7d..6ed07844eb24 100644 --- a/include/net/cfg802154.h +++ b/include/net/cfg802154.h @@ -214,7 +214,7 @@ struct wpan_phy { /* the network namespace this phy lives in currently */ possible_net_t _net; - char priv[0] __aligned(NETDEV_ALIGN); + char priv[] __aligned(NETDEV_ALIGN); }; static inline struct net *wpan_phy_net(struct wpan_phy *wpan_phy) |