> -----Original Message-----
> From: Kevin Traynor <ktray...@redhat.com>
> Sent: Friday, May 15, 2020 7:28 AM
> To: dev@dpdk.org; Wang, Yipeng1 <yipeng1.w...@intel.com>; Gobriel,
> Sameh <sameh.gobr...@intel.com>; Richardson, Bruce
> <bruce.richard...@intel.com>
> Cc: honnappa.nagaraha...@arm.com; Yigit, Ferruh <ferruh.yi...@intel.com>;
> david.march...@redhat.com; Kevin Traynor <ktray...@redhat.com>;
> sta...@dpdk.org
> Subject: [PATCH] hash: fix gcc 10 maybe-uninitialized warning
>
> gcc 10.1.1 reports a warning for the ext_bkt_id variable:
>
> ../lib/librte_hash/rte_cuckoo_hash.c:
> In function ‘__rte_hash_add_key_with_hash’:
> ../lib/librte_hash/rte_cuckoo_hash.c:1104:29:
> warning: ‘ext_bkt_id’ may be used uninitialized in this function [-Wmaybe-
> uninitialized]
> 1104 | (h->buckets_ext[ext_bkt_id - 1]).sig_current[0] = short_sig;
> | ~~~~~~~~~~~^~~
>
> The return value of rte_ring_sc_dequeue_elem() is already checked, but
> also initialize ext_bkt_id to zero (invalid value) and check that it also
> overwritten.
>
> Fixes: fbfe568103b0 ("hash: use 32-bit elements rings to save memory")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Kevin Traynor <ktray...@redhat.com>
> ---
> lib/librte_hash/rte_cuckoo_hash.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_hash/rte_cuckoo_hash.c
> b/lib/librte_hash/rte_cuckoo_hash.c
> index 38767a8a1..90cb99b0e 100644
> --- a/lib/librte_hash/rte_cuckoo_hash.c
> +++ b/lib/librte_hash/rte_cuckoo_hash.c
> @@ -940,6 +940,6 @@ __rte_hash_add_key_with_hash(const struct
> rte_hash *h, const void *key,
> struct rte_hash_bucket *prim_bkt, *sec_bkt, *cur_bkt;
> struct rte_hash_key *new_k, *keys = h->key_store;
> + uint32_t ext_bkt_id = 0;
> uint32_t slot_id;
> - uint32_t ext_bkt_id;
> int ret;
> unsigned n_slots;
> @@ -1096,5 +1096,6 @@ __rte_hash_add_key_with_hash(const struct
> rte_hash *h, const void *key,
> */
> if (rte_ring_sc_dequeue_elem(h->free_ext_bkts, &ext_bkt_id,
> - sizeof(uint32_t)) != 0) {
> + sizeof(uint32_t)) != 0 ||
> + ext_bkt_id == 0) {
[Wang, Yipeng]
If convenient, it would be better to make the two lines aligned with same
indent...
> ret = -ENOSPC;
> goto failure;
> --
> 2.21.3
[Wang, Yipeng]
Thanks for the fix. I think It is also better code in general.
Acked-by: Yipeng Wang <yipeng1.w...@intel.com>
