Add check to see if stack pointer is off the stack according to the memory

mappings when rating Linux exploitability.

R=ivanpe@chromium.org

Review URL: https://codereview.chromium.org/1286033002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1487 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/processor/exploitability_linux.h

@@ -58,6 +58,10 @@ class ExploitabilityLinux : public Exploitability {
   // This method checks the exception that triggered the creation of the
   // minidump and reports whether the exception suggests no exploitability.
   bool BenignCrashTrigger(const MDRawExceptionStream *raw_exception_stream);
+
+  // Checks if the stack pointer points to a memory mapping that is not
+  // labelled as the stack.
+  bool StackPointerOffStack(uint64_t stack_ptr);
 };
 
 }  // namespace google_breakpad