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>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct mlxsw_core_port *ports;
unsigned int max_ports;
bool fw_flash_in_progress;
- unsigned long driver_priv[0];
+ unsigned long driver_priv[];
/* driver_priv has to be always the last item */
};
* is index inside "blocks"
*/
struct mlxsw_afk_element_usage elusage;
- const struct mlxsw_afk_block *blocks[0];
+ const struct mlxsw_afk_block *blocks[];
};
static bool
struct mlxsw_sp1_kvdl_part {
struct mlxsw_sp1_kvdl_part_info info;
- unsigned long usage[0]; /* Entries */
+ unsigned long usage[]; /* Entries */
};
struct mlxsw_sp1_kvdl {
unsigned int usage_bit_count;
unsigned int indexes_per_usage_bit;
unsigned int last_allocated_bit;
- unsigned long usage[0]; /* Usage bits */
+ unsigned long usage[]; /* Usage bits */
};
struct mlxsw_sp2_kvdl {
struct mlxsw_sp_acl_ruleset_ht_key ht_key;
struct rhashtable rule_ht;
unsigned int ref_count;
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
u64 last_used;
u64 last_packets;
u64 last_bytes;
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
struct mlxsw_sp_acl_bf {
struct mutex lock; /* Protects Bloom Filter updates. */
unsigned int bank_size;
- refcount_t refcnt[0];
+ refcount_t refcnt[];
};
/* Bloom filter uses a crc-16 hash over chunks of data which contain 4 key
struct mlxsw_sp_acl_tcam_chunk {
struct mlxsw_sp_acl_tcam_vchunk *vchunk;
struct mlxsw_sp_acl_tcam_region *region;
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
struct mlxsw_sp_acl_tcam_entry {
struct mlxsw_sp_acl_tcam_ventry *ventry;
struct mlxsw_sp_acl_tcam_chunk *chunk;
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
struct mutex lock; /* guards vregion list */
struct list_head vregion_list;
u32 vregion_rehash_intrvl; /* ms */
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
char tcam_region_info[MLXSW_REG_PXXX_TCAM_REGION_INFO_LEN];
struct mlxsw_afk_key_info *key_info;
struct mlxsw_sp *mlxsw_sp;
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
struct mlxsw_sp_kvdl {
const struct mlxsw_sp_kvdl_ops *kvdl_ops;
- unsigned long priv[0];
+ unsigned long priv[];
/* priv has to be always the last item */
};
struct list_head route_list;
struct rhashtable route_ht;
const struct mlxsw_sp_mr_table_ops *ops;
- char catchall_route_priv[0];
+ char catchall_route_priv[];
/* catchall_route_priv has to be always the last item */
};
struct mlxsw_sp_nve_mc_list *mc_list;
const struct mlxsw_sp_nve_mc_record_ops *ops;
u32 kvdl_index;
- struct mlxsw_sp_nve_mc_entry entries[0];
+ struct mlxsw_sp_nve_mc_entry entries[];
};
struct mlxsw_sp_nve_mc_list {