From: Sage Weil <sage@redhat.com>
Date: Fri, 16 Jun 2017 02:18:08 +0000 (-0400)
Subject: messages/MOSDPing: initialize MOSDPing padding
X-Git-Tag: v12.1.0~110^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=9beaf5efd74daa8c15e50b42583264d1252a85f5;p=ceph.git

messages/MOSDPing: initialize MOSDPing padding

This memory must be initialized or else valgrind will be very unhappy.

Avoid the cost of zeroing (or even allocating) the buffer for normal
padding values by (re)using a static zero buffer.

Fixes: http://tracker.ceph.com/issues/20323
Signed-off-by: Sage Weil <sage@redhat.com>
---

diff --git a/src/messages/MOSDPing.h b/src/messages/MOSDPing.h
index 7a8bf2f986f0..22d24d6aae7a 100644
--- a/src/messages/MOSDPing.h
+++ b/src/messages/MOSDPing.h
@@ -99,10 +99,22 @@ public:
     ::encode(op, payload);
     ::encode(peer_stat, payload);
     ::encode(stamp, payload);
-    bufferptr size_bp(MAX(min_message_size - payload.length(), 0));
-    bufferlist size_bl;;
-    size_bl.push_back(size_bp);
-    ::encode(size_bl, payload);
+
+    bufferlist pad;
+    size_t s = MAX(min_message_size - payload.length(), 0);
+    // this should be big enough for normal min_message padding sizes. since
+    // we are targetting jumbo ethernet frames around 9000 bytes, 16k should
+    // be more than sufficient!  the compiler will statically zero this so
+    // that at runtime we are only adding a bufferptr reference to it.
+    static char zeros[16384] = {};
+    while (s > sizeof(zeros)) {
+      pad.append(buffer::create_static(sizeof(zeros), zeros));
+      s -= sizeof(zeros);
+    }
+    if (s) {
+      pad.append(buffer::create_static(s, zeros));
+    }
+    ::encode(pad, payload);
   }
 
   const char *get_type_name() const override { return "osd_ping"; }