src/share/vm/utilities/vmError.cpp

rev 7970 : 8074552:  SafeFetch32 and SafeFetchN do not work in error handling
Summary: handle SafeFetch faults in secondary signal handlers
Reviewed-by: dholmes
Contributed-by: Thomas Stuefe

*** 356,378 ****
  #ifndef PRODUCT
    // Error handler self tests
  
    // test secondary error handling. Test it twice, to test that resetting
    // error handler after a secondary crash works.
!   STEP(13, "(test secondary crash 1)")
      if (_verbose && TestCrashInErrorHandler != 0) {
        st->print_cr("Will crash now (TestCrashInErrorHandler=%d)...",
          TestCrashInErrorHandler);
        controlled_crash(TestCrashInErrorHandler);
      }
  
!   STEP(14, "(test secondary crash 2)")
      if (_verbose && TestCrashInErrorHandler != 0) {
        st->print_cr("Will crash now (TestCrashInErrorHandler=%d)...",
          TestCrashInErrorHandler);
        controlled_crash(TestCrashInErrorHandler);
      }
  #endif // PRODUCT
  
    STEP(15, "(printing type of error)")
  
       switch(_id) {
--- 356,398 ----
  #ifndef PRODUCT
    // Error handler self tests
  
    // test secondary error handling. Test it twice, to test that resetting
    // error handler after a secondary crash works.
!   STEP(11, "(test secondary crash 1)")
      if (_verbose && TestCrashInErrorHandler != 0) {
        st->print_cr("Will crash now (TestCrashInErrorHandler=%d)...",
          TestCrashInErrorHandler);
        controlled_crash(TestCrashInErrorHandler);
      }
  
!   STEP(12, "(test secondary crash 2)")
      if (_verbose && TestCrashInErrorHandler != 0) {
        st->print_cr("Will crash now (TestCrashInErrorHandler=%d)...",
          TestCrashInErrorHandler);
        controlled_crash(TestCrashInErrorHandler);
      }
+ 
+   STEP(13, "(test safefetch in error handler)")
+     // test whether it is safe to use SafeFetch32 in Crash Handler. Test twice
+     // to test that resetting the signal handler works correctly.
+     if (_verbose && TestSafeFetchInErrorHandler) {
+       st->print_cr("Will test SafeFetch...");
+       if (CanUseSafeFetch32()) {
+         int* const invalid_pointer = (int*) get_segfault_address();
+         const int x = 0x76543210;
+         int i1 = SafeFetch32(invalid_pointer, x);
+         int i2 = SafeFetch32(invalid_pointer, x);
+         if (i1 == x && i2 == x) {
+           st->print_cr("SafeFetch OK."); // Correctly deflected and returned default pattern
+         } else {
+           st->print_cr("??");
+         }
+       } else {
+         st->print_cr("not possible; skipped.");
+       }
+     }
  #endif // PRODUCT
  
    STEP(15, "(printing type of error)")
  
       switch(_id) {