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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-02 15:10:51 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-02 22:16:28 +0300 |
| commit | 8f5c69f96a5030899437e3e76dc4495c99e2258a (patch) | |
| tree | 200b5e59295739eb5d60b3c980282ef54dc727d9 | |
| parent | 48b77df665e0a268b61a795208e647b6b7bb7e00 (diff) | |
| download | linux-8f5c69f96a5030899437e3e76dc4495c99e2258a.tar.xz | |
bna: bnad: 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-- | drivers/net/ethernet/brocade/bna/bnad.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/brocade/bna/bnad.h b/drivers/net/ethernet/brocade/bna/bnad.h index 492a02d54f14..bfa58b40dc3f 100644 --- a/drivers/net/ethernet/brocade/bna/bnad.h +++ b/drivers/net/ethernet/brocade/bna/bnad.h @@ -253,7 +253,7 @@ struct bnad_rx_unmap_q { int alloc_order; u32 map_size; enum bnad_rxbuf_type type; - struct bnad_rx_unmap unmap[0] ____cacheline_aligned; + struct bnad_rx_unmap unmap[] ____cacheline_aligned; }; #define BNAD_PCI_DEV_IS_CAT2(_bnad) \ |