From: xie xingguo <xie.xingguo@zte.com.cn>
Date: Thu, 18 Aug 2016 11:54:07 +0000 (+0800)
Subject: mon/PGMonitor: fix potential underflow
X-Git-Tag: v11.0.1~422^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=cc75e1a2a17cbbbc92ab0ec87ad40b55f966aff2;p=ceph.git

mon/PGMonitor: fix potential underflow

h.h.size() could be 0(theoretically), so "h.h.size() - 1" could underflow.

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>
---

diff --git a/src/mon/PGMonitor.cc b/src/mon/PGMonitor.cc
index d07f5110df88..b6c797d1649c 100644
--- a/src/mon/PGMonitor.cc
+++ b/src/mon/PGMonitor.cc
@@ -2077,6 +2077,9 @@ int PGMonitor::_warn_slow_request_histogram(const pow2_hist_t& h, string suffix,
                                             list<pair<health_status_t,string> >& summary,
                                             list<pair<health_status_t,string> > *detail) const
 {
+  if (h.h.empty())
+    return 0;
+
   unsigned sum = 0;
   for (unsigned i = h.h.size() - 1; i > 0; --i) {
     float ub = (float)(1 << i) / 1000.0;