title: Is there any crash that not related to signal
body: <p>Usually a crash report in Linux could look like this below:</p>
  
  <pre><code>[jack-VirtualBox:14564] *** Process received signal ***
  [jack-VirtualBox:14564] Signal: Segmentation fault (11)
  [jack-VirtualBox:14564] Signal code:  (-6)
  [jack-VirtualBox:14564] Failing at address: 0x3e8000038e4
  [jack-VirtualBox:14564] [ 0] /lib/x86_64-linux-gnu/libpthread.so.0(+0x11390)[0x7f1c048f0390]
  [jack-VirtualBox:14564] [ 1] /lib/x86_64-linux-gnu/libpthread.so.0(raise+0x29)[0x7f1c048f0269]
  [jack-VirtualBox:14564] [ 2] ../test/send_recv[0x400b6c]
  [jack-VirtualBox:14564] [ 3] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f1c04535830]
  [jack-VirtualBox:14564] [ 4] ../test/send_recv[0x4009d9]
  [jack-VirtualBox:14564] *** End of error message ***
  </code></pre>
  
  <p>One program does something unexpected by software or hardware. A signal is sent to that program, (1) signal handled by signal handler (2) no signal handler registered, default handler triggered.</p>
  
  <p>So it looks like all crash and hang of program is related to signal. Is there any possibility that a crash or hang is not caused by a signal? </p>