src/hotspot/share/runtime/os.cpp

rev 53535 : 8217994: os::print_hex_dump should be more resilient against unreadable memory
Reviewed-by: XXX

*** 883,898 ****
--- 883,907 ----
    }
  
    address p = start;
    st->print(PTR_FORMAT ":   ", p2i(start));
    while (p < end) {
+     if (is_readable_pointer(p)) {
        switch (unitsize) {
          case 1: st->print("%02x", *(u1*)p); break;
          case 2: st->print("%04x", *(u2*)p); break;
          case 4: st->print("%08x", *(u4*)p); break;
          case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
        }
+     } else {
+       switch (unitsize) {
+         case 1: st->print("%2s",  "??");               break;
+         case 2: st->print("%4s",  "????");             break;
+         case 4: st->print("%8s",  "????????");         break;
+         case 8: st->print("%16s", "????????????????"); break;
+       }
+     }
      p += unitsize;
      cols++;
      if (cols >= cols_per_line && p < end) {
         cols = 0;
         st->cr();