[PATCH 1/2] eal: fix failure race and behavior of thread create

[Tyler Retzlaff]

In rte_thread_create setting affinity after pthread_create may fail.
Such a failure should result in the entire rte_thread_create failing
but doesn't.

Additionally if there is a failure to set affinity a race exists where
the creating thread will free ctx and depending on scheduling of the new
thread it may also free ctx (double free).

Resolve both of the above issues by using the pthread_setaffinity_np
prior to thread creation to set the affinity of the created thread. By
doing this no failure paths exist after pthread_create returns
successfully.

Fixes: ce6e911d20f6 ("eal: add thread lifetime API")
Cc: stable at dpdk.org
Cc: roretzla at linux.microsoft.com

Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
---
 lib/eal/unix/rte_thread.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/lib/eal/unix/rte_thread.c b/lib/eal/unix/rte_thread.c
index 37ebfcf..5bf633b 100644
--- a/lib/eal/unix/rte_thread.c
+++ b/lib/eal/unix/rte_thread.c
@@ -155,6 +155,17 @@ struct thread_routine_ctx {
 			RTE_LOG(DEBUG, EAL, "pthread_attr_setschedparam failed\n");
 			goto cleanup;
 		}
+
+		if (CPU_COUNT(&thread_attr->cpuset) > 0) {
+			ret = pthread_attr_setaffinity_np(attrp,
+				sizeof(thread_attr->cpuset),
+				&thread_attr->cpuset);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL,
+					"pthread_attr_setaffinity_np failed\n");
+				goto cleanup;
+			}
+		}
 	}
 
 	ret = pthread_create((pthread_t *)&thread_id->opaque_id, attrp,
@@ -164,15 +175,6 @@ struct thread_routine_ctx {
 		goto cleanup;
 	}
 
-	if (thread_attr != NULL && CPU_COUNT(&thread_attr->cpuset) > 0) {
-		ret = rte_thread_set_affinity_by_id(*thread_id,
-			&thread_attr->cpuset);
-		if (ret != 0) {
-			RTE_LOG(DEBUG, EAL, "rte_thread_set_affinity_by_id failed\n");
-			goto cleanup;
-		}
-	}
-
 	ctx = NULL;
 cleanup:
 	free(ctx);
-- 
1.8.3.1