diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-28 07:56:29 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-28 12:08:37 -0800 |
| commit | 749db093040788ff474937d2452d4cf0176b5a1f (patch) | |
| tree | 324a09d84638f35b6a4a36441daa2d05188912a9 | |
| parent | d2afb41ae60435cbe5d9d1078a7d90de04e571b8 (diff) | |
| download | linux-749db093040788ff474937d2452d4cf0176b5a1f.tar.bz2 | |
bonding: 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>
| -rw-r--r-- | include/net/bonding.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/bonding.h b/include/net/bonding.h index 3d56b026bb9e..dc2ce31a1f52 100644 --- a/include/net/bonding.h +++ b/include/net/bonding.h @@ -183,7 +183,7 @@ struct slave { struct bond_up_slave { unsigned int count; struct rcu_head rcu; - struct slave *arr[0]; + struct slave *arr[]; }; /* |