diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-24 10:30:24 -0600 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-02-24 15:26:17 -0800 |
commit | 65dc2f1a44df01eab3c93b7ecdd3fb393f9e81a2 (patch) | |
tree | e63527dd8045b57f18bdb791c2de7256717b21a1 /drivers/net/ethernet/chelsio/cxgb4/l2t.c | |
parent | 59bc954c7a2572e1c903012ab722eba942a5d65c (diff) |
chelsio: 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/net/ethernet/chelsio/cxgb4/l2t.c')
-rw-r--r-- | drivers/net/ethernet/chelsio/cxgb4/l2t.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.c b/drivers/net/ethernet/chelsio/cxgb4/l2t.c index 1a16449..12c3354 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/l2t.c +++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.c @@ -59,7 +59,7 @@ struct l2t_data { rwlock_t lock; atomic_t nfree; /* number of free entries */ struct l2t_entry *rover; /* starting point for next allocation */ - struct l2t_entry l2tab[0]; /* MUST BE LAST */ + struct l2t_entry l2tab[]; /* MUST BE LAST */ }; static inline unsigned int vlan_prio(const struct l2t_entry *e) |