global/signal_handler: do not log if SEGV originated inside log code

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/global/signal_handler.cc b/src/global/signal_handler.cc
index ffdc5402cafe54db1592807b4cd979a4c046e466..edca694f1c082a450dacba51fb9bf3d6cb30bff7 100644 (file)
--- a/src/global/signal_handler.cc
+++ b/src/global/signal_handler.cc
@@ -84,23 +84,27 @@ static void handle_fatal_signal(int signum)
   dout_emergency(buf);
   pidfile_remove();
 
-  // TODO: don't use an ostringstream here. It could call malloc(), which we
-  // don't want inside a signal handler.
-  // Also fix the backtrace code not to allocate memory.
-  BackTrace bt(0);
-  ostringstream oss;
-  bt.print(oss);
-  dout_emergency(oss.str());
-
-  // dump to log.  this uses the heap extensively, but we're better
-  // off trying than not.
-  derr << buf << std::endl;
-  bt.print(*_dout);
-  *_dout << " NOTE: a copy of the executable, or `objdump -rdS <executable>` "
-        << "is needed to interpret this.\n"
-        << dendl;
-
-  g_ceph_context->_log->dump_recent();
+  // avoid recursion back into logging code if that is where
+  // we got the SEGV.
+  if (!g_ceph_context->_log->is_inside_log_lock()) {
+    // TODO: don't use an ostringstream here. It could call malloc(), which we
+    // don't want inside a signal handler.
+    // Also fix the backtrace code not to allocate memory.
+    BackTrace bt(0);
+    ostringstream oss;
+    bt.print(oss);
+    dout_emergency(oss.str());
+
+    // dump to log.  this uses the heap extensively, but we're better
+    // off trying than not.
+    derr << buf << std::endl;
+    bt.print(*_dout);
+    *_dout << " NOTE: a copy of the executable, or `objdump -rdS <executable>` "
+          << "is needed to interpret this.\n"
+          << dendl;
+
+    g_ceph_context->_log->dump_recent();
+  }
 
   reraise_fatal(signum);
 }