diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-20 16:59:14 +0300 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2020-03-15 17:20:16 +0300 |
commit | 6daf14140129d30207ed6a0a69851fa6a3636bda (patch) | |
tree | 43f5f5d662db9cfc241ba1c848f17694b95a16ff /include/uapi/linux/netfilter_bridge | |
parent | eb9d7af3b7bd6d1b51c6522de53a5bf9c57e81db (diff) | |
download | linux-6daf14140129d30207ed6a0a69851fa6a3636bda.tar.xz |
netfilter: 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]
Lastly, fix checkpatch.pl warning
WARNING: __aligned(size) is preferred over __attribute__((aligned(size)))
in net/bridge/netfilter/ebtables.c
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: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include/uapi/linux/netfilter_bridge')
-rw-r--r-- | include/uapi/linux/netfilter_bridge/ebt_among.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/uapi/linux/netfilter_bridge/ebt_among.h b/include/uapi/linux/netfilter_bridge/ebt_among.h index 9acf757bc1f7..73b26a280c4f 100644 --- a/include/uapi/linux/netfilter_bridge/ebt_among.h +++ b/include/uapi/linux/netfilter_bridge/ebt_among.h @@ -40,7 +40,7 @@ struct ebt_mac_wormhash_tuple { struct ebt_mac_wormhash { int table[257]; int poolsize; - struct ebt_mac_wormhash_tuple pool[0]; + struct ebt_mac_wormhash_tuple pool[]; }; #define ebt_mac_wormhash_size(x) ((x) ? sizeof(struct ebt_mac_wormhash) \ |