From da5957821bdd684a50dcb639fb7798936fb2d981 Mon Sep 17 00:00:00 2001 From: Anatoly Burakov Date: Fri, 2 Mar 2018 08:41:37 +0000 Subject: [PATCH] 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: 783b6e54971d ("eal: add synchronous multi-process communication") Cc: stable@dpdk.org Signed-off-by: Anatoly Burakov Acked-by: Jianfeng Tan --- lib/librte_eal/common/eal_common_proc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/lib/librte_eal/common/eal_common_proc.c b/lib/librte_eal/common/eal_common_proc.c index 3a1088e2f4..da7930f564 100644 --- a/lib/librte_eal/common/eal_common_proc.c +++ b/lib/librte_eal/common/eal_common_proc.c @@ -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 */ -- 2.20.1