In current implementation of rte_hash_iterate(), it
tries to obtain the lock after the while loop. However,
this may lead to a bug. Notice the following racing condition:
1. The while loop above finishes because it finds
a not empty slot. But it does so without a lock.
2. Then we get the lock.
3. The position that was once not empty is now empty.
BUG because next_key is invalid.
This patch fixes this small bug.
Signed-off-by: Qiaobin Fu <qiaob...@bu.edu>
Reviewed-by: Michel Machado <mic...@digirati.com.br>
---
lib/librte_hash/rte_cuckoo_hash.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/lib/librte_hash/rte_cuckoo_hash.c
b/lib/librte_hash/rte_cuckoo_hash.c
index f7b86c8c9..a3e76684d 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -1317,16 +1317,18 @@ rte_hash_iterate(const struct rte_hash *h, const void
**key, void **data, uint32
bucket_idx = *next / RTE_HASH_BUCKET_ENTRIES;
idx = *next % RTE_HASH_BUCKET_ENTRIES;
+ __hash_rw_reader_lock(h);
/* If current position is empty, go to the next one */
while (h->buckets[bucket_idx].key_idx[idx] == EMPTY_SLOT) {
(*next)++;
/* End of table */
- if (*next == total_entries)
+ if (*next == total_entries) {
+ __hash_rw_reader_unlock(h);
return -ENOENT;
+ }
bucket_idx = *next / RTE_HASH_BUCKET_ENTRIES;
idx = *next % RTE_HASH_BUCKET_ENTRIES;
}
- __hash_rw_reader_lock(h);
/* Get position of entry in key table */
position = h->buckets[bucket_idx].key_idx[idx];
next_key = (struct rte_hash_key *) ((char *)h->key_store +
--
2.17.1
