title: IsBadReadPtr analogue on Unix
body: <p>Is there a function analogous to <a href="http://msdn.microsoft.com/en-us/library/aa366713%28VS.85%29.aspx" rel="nofollow">IsBadReadPtr</a> in Unix? At least some functionalities of IsBadReadPtr? 
  I want to write a procedure which would react if something bad happens to a process (like <code>SIGSEGV</code>) and recover some information. But I want to check the pointers to make sure that the data is not corrupt and see if they can be accessed safely. Otherwise the crash handling procedure itself will crash, thus becoming useless. </p>
  
  <p>Any suggestions?</p>