From: E. Scott Daniels <daniels@research.att.com>
Date: Thu, 20 Oct 2016 13:34:41 +0000 (-0400)
Subject: ethdev: prevent duplicate event callback
X-Git-Tag: spdx-start~5497
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=dbffbf80e99aad7c7a5ffaf78e750ae69963f9e0;p=dpdk.git

ethdev: prevent duplicate event callback

This change prevents the attempt to add a structure which is
already on the callback list. If a struct with matching
parameters is found on the list, then no action is taken.

Fixes: ac2f69c ("ethdev: fix crash if malloc of user callback fails")

Signed-off-by: E. Scott Daniels <daniels@research.att.com>
Acked-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
---

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 0d9d9c1a71..fde8112f12 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -2449,14 +2449,15 @@ rte_eth_dev_callback_register(uint8_t port_id,
 	}
 
 	/* create a new callback. */
-	if (user_cb == NULL)
+	if (user_cb == NULL) {
 		user_cb = rte_zmalloc("INTR_USER_CALLBACK",
 					sizeof(struct rte_eth_dev_callback), 0);
-	if (user_cb != NULL) {
-		user_cb->cb_fn = cb_fn;
-		user_cb->cb_arg = cb_arg;
-		user_cb->event = event;
-		TAILQ_INSERT_TAIL(&(dev->link_intr_cbs), user_cb, next);
+		if (user_cb != NULL) {
+			user_cb->cb_fn = cb_fn;
+			user_cb->cb_arg = cb_arg;
+			user_cb->event = event;
+			TAILQ_INSERT_TAIL(&(dev->link_intr_cbs), user_cb, next);
+		}
 	}
 
 	rte_spinlock_unlock(&rte_eth_dev_cb_lock);