ipc: remove panic in async request

EAL should not crash when setting alarm fails. Also, remove the
profanity in error message.

Fixes: daf9bfca717e ("ipc: remove thread for async requests")
Cc: stable@dpdk.org
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>

diff --git a/lib/librte_eal/common/eal_common_proc.c b/lib/librte_eal/common/eal_common_proc.c
index 97663d3..f65ef56 100644 (file)
--- a/lib/librte_eal/common/eal_common_proc.c
+++ b/lib/librte_eal/common/eal_common_proc.c
@@ -800,7 +800,7 @@ mp_request_async(const char *dst, struct rte_mp_msg *req,
 {
        struct rte_mp_msg *reply_msg;
        struct pending_request *pending_req, *exist;
-       int ret;
+       int ret = -1;
 
        pending_req = calloc(1, sizeof(*pending_req));
        reply_msg = calloc(1, sizeof(*reply_msg));
@@ -827,6 +827,28 @@ mp_request_async(const char *dst, struct rte_mp_msg *req,
                goto fail;
        }
 
+       /*
+        * set the alarm before sending message. there are two possible error
+        * scenarios to consider here:
+        *
+        * - if the alarm set fails, we free the memory right there
+        * - if the alarm set succeeds but sending message fails, then the alarm
+        *   will trigger and clean up the memory
+        *
+        * Even if the alarm triggers too early (i.e. immediately), we're still
+        * holding the lock to pending requests queue, so the interrupt thread
+        * will just spin until we release the lock, and either release the
+        * memory, or doesn't find any pending requests in the queue because we
+        * never added any due to send message failure.
+        */
+       if (rte_eal_alarm_set(ts->tv_sec * 1000000 + ts->tv_nsec / 1000,
+                             async_reply_handle, pending_req) < 0) {
+               RTE_LOG(ERR, EAL, "Fail to set alarm for request %s:%s\n",
+                       dst, req->name);
+               ret = -1;
+               goto fail;
+       }
+
        ret = send_msg(dst, req, MP_REQ);
        if (ret < 0) {
                RTE_LOG(ERR, EAL, "Fail to send request %s:%s\n",
@@ -841,13 +863,6 @@ mp_request_async(const char *dst, struct rte_mp_msg *req,
 
        param->user_reply.nb_sent++;
 
-       if (rte_eal_alarm_set(ts->tv_sec * 1000000 + ts->tv_nsec / 1000,
-                             async_reply_handle, pending_req) < 0) {
-               RTE_LOG(ERR, EAL, "Fail to set alarm for request %s:%s\n",
-                       dst, req->name);
-               rte_panic("Fix the above shit to properly free all memory\n");
-       }
-
        return 0;
 fail:
        free(pending_req);