[SPARK-3755][Core] avoid trying privileged port when request a non-privileged port

pwendell, ```tryPort``` is not compatible with old code in last PR, this is to fix it.
And after discuss with srowen renamed the title to "avoid trying privileged port when request a non-privileged port". Plz refer to the discuss for detail.

Author: scwf <wangfei1@huawei.com>

Closes #2623 from scwf/1-1024 and squashes the following commits:

10a4437 [scwf] add comment
de3fd17 [scwf] do not try privileged port when request a non-privileged port
42cb0fa [scwf] make tryPort compatible with old code
cb8cc76 [scwf] do not use port 1 - 1024

1 files changed, 6 insertions, 1 deletions

diff --git a/core/src/main/scala/org/apache/spark/util/Utils.scala b/core/src/main/scala/org/apache/spark/util/Utils.scala
index b3025c6ec3..9399ddab76 100644
--- a/core/src/main/scala/org/apache/spark/util/Utils.scala
+++ b/core/src/main/scala/org/apache/spark/util/Utils.scala
@@ -1439,7 +1439,12 @@ private[spark] object Utils extends Logging {
     val serviceString = if (serviceName.isEmpty) "" else s" '$serviceName'"
     for (offset <- 0 to maxRetries) {
       // Do not increment port if startPort is 0, which is treated as a special port
-      val tryPort = if (startPort == 0) startPort else (startPort + offset) % 65536
+      val tryPort = if (startPort == 0) {
+        startPort
+      } else {
+        // If the new port wraps around, do not try a privilege port
+        ((startPort + offset - 1024) % (65536 - 1024)) + 1024
+      }
       try {
         val (service, port) = startService(tryPort)
         logInfo(s"Successfully started service$serviceString on port $port.")