src/share/vm/utilities/debug.cpp

rev 7758 : 8065895 Synchronous signals during error reporting may terminate or hang VM process
Reviewed-by: dholmes,gziemski
Contributed-by: stuefe

*** 314,341 ****
  }
  
  #ifndef PRODUCT
  #include <signal.h>
  
  void test_error_handler() {
!   uintx test_num = ErrorHandlerTest;
!   if (test_num == 0) return;
  
    // If asserts are disabled, use the corresponding guarantee instead.
!   size_t n = test_num;
!   NOT_DEBUG(if (n <= 2) n += 2);
  
    const char* const str = "hello";
    const size_t      num = (size_t)os::vm_page_size();
  
    const char* const eol = os::line_separator();
    const char* const msg = "this message should be truncated during formatting";
    char * const dataPtr = NULL;  // bad data pointer
    const void (*funcPtr)(void) = (const void(*)()) 0xF;  // bad function pointer
  
    // Keep this in sync with test/runtime/6888954/vmerrors.sh.
!   switch (n) {
      case  1: vmassert(str == NULL, "expected null");
      case  2: vmassert(num == 1023 && *str == 'X',
                        err_msg("num=" SIZE_FORMAT " str=\"%s\"", num, str));
      case  3: guarantee(str == NULL, "expected null");
      case  4: guarantee(num == 1023 && *str == 'X',
--- 314,375 ----
  }
  
  #ifndef PRODUCT
  #include <signal.h>
  
+ typedef void (*voidfun_t)();
+ // Crash with an authentic sigfpe
+ static void crash_with_sigfpe() {
+   // generate a native synchronous SIGFPE where possible;
+   // if that did not cause a signal (e.g. on ppc), just
+   // raise the signal.
+   volatile int x = 0;
+   volatile int y = 1/x;
+ #ifndef _WIN32
+   raise(SIGFPE);
+ #endif
+ } // end: crash_with_sigfpe
+ 
+ // crash with sigsegv at non-null address.
+ static void crash_with_segfault() {
+ 
+   char* const crash_addr = (char*) get_segfault_address();
+   *crash_addr = 'X';
+ 
+ } // end: crash_with_segfault
+ 
+ // returns an address which is guaranteed to generate a SIGSEGV on read,
+ // for test purposes, which is not NULL and contains bits in every word
+ void* get_segfault_address() {
+   return (void*)
+ #ifdef _LP64
+     0xABC0000000000ABCULL;
+ #else
+     0x00000ABC;
+ #endif
+ }
+ 
  void test_error_handler() {
!   controlled_crash(ErrorHandlerTest);
! }
! 
! void controlled_crash(int how) {
!   if (how == 0) return;
  
    // If asserts are disabled, use the corresponding guarantee instead.
!   NOT_DEBUG(if (how <= 2) how += 2);
  
    const char* const str = "hello";
    const size_t      num = (size_t)os::vm_page_size();
  
    const char* const eol = os::line_separator();
    const char* const msg = "this message should be truncated during formatting";
    char * const dataPtr = NULL;  // bad data pointer
    const void (*funcPtr)(void) = (const void(*)()) 0xF;  // bad function pointer
  
    // Keep this in sync with test/runtime/6888954/vmerrors.sh.
!   switch (how) {
      case  1: vmassert(str == NULL, "expected null");
      case  2: vmassert(num == 1023 && *str == 'X',
                        err_msg("num=" SIZE_FORMAT " str=\"%s\"", num, str));
      case  3: guarantee(str == NULL, "expected null");
      case  4: guarantee(num == 1023 && *str == 'X',
*** 356,367 ****
      // so "break" out to the ShouldNotReachHere().
      case 12: *dataPtr = '\0'; break;
      // There's no guarantee the bad function pointer will crash us
      // so "break" out to the ShouldNotReachHere().
      case 13: (*funcPtr)(); break;
  
!     default: tty->print_cr("ERROR: %d: unexpected test_num value.", n);
    }
    ShouldNotReachHere();
  }
  #endif // !PRODUCT
  
--- 390,403 ----
      // so "break" out to the ShouldNotReachHere().
      case 12: *dataPtr = '\0'; break;
      // There's no guarantee the bad function pointer will crash us
      // so "break" out to the ShouldNotReachHere().
      case 13: (*funcPtr)(); break;
+     case 14: crash_with_segfault(); break;
+     case 15: crash_with_sigfpe(); break;
  
!     default: tty->print_cr("ERROR: %d: unexpected test_num value.", how);
    }
    ShouldNotReachHere();
  }
  #endif // !PRODUCT