eal: fix race condition in IPC request

Unlocking the action list before sending message and locking it
again afterwards introduces a window where a response might
arrive before we have a chance to start waiting on a condition,
resulting in timeouts on valid messages.

Fixes: 783b6e5497 ("eal: add synchronous multi-process communication")
Cc: stable@dpdk.org

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Jianfeng Tan <jianfeng.tan@intel.com>
This commit is contained in:
Anatoly Burakov 2018-03-02 08:41:37 +00:00 committed by Thomas Monjalon
parent 139653a09a
commit da5957821b

View File

@ -561,10 +561,10 @@ mp_request_one(const char *dst, struct rte_mp_msg *req,
exist = find_sync_request(dst, req->name);
if (!exist)
TAILQ_INSERT_TAIL(&sync_requests.requests, &sync_req, next);
pthread_mutex_unlock(&sync_requests.lock);
if (exist) {
RTE_LOG(ERR, EAL, "A pending request %s:%s\n", dst, req->name);
rte_errno = EEXIST;
pthread_mutex_unlock(&sync_requests.lock);
return -1;
}
@ -578,7 +578,6 @@ mp_request_one(const char *dst, struct rte_mp_msg *req,
reply->nb_sent++;
pthread_mutex_lock(&sync_requests.lock);
do {
pthread_cond_timedwait(&sync_req.cond, &sync_requests.lock, ts);
/* Check spurious wakeups */