Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8160399

is_oop_or_null involves undefined behavior

    XMLWordPrintable

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 9
    • Fix Version/s: 10
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b22
    • CPU:
      generic
    • OS:
      generic

      Description

      oopDesc::is_oop_or_null is an ordinary member function, whose definition includes a test using the expression "this == NULL". However, this can be assumed to never be NULL, as that would require undefined behavior. So the compiler is free to optimize away that test, eliminating the "_or_null" part of the function's intended semantics. Recent versions of gcc (like gcc 6) seem to be more aggressive about optimizations around that sort of thing, leading to crashes.

        Attachments

          Issue Links

          duplicates

          Sub-task - The sub-task of the issue JDK-8160363 assert(discovered->is_oop_or_null()) failed: Expected an oop or NULL for discovered field at 0x0000000000000000

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved
          relates to

          Bug - A problem which impairs or prevents the functions of the product. JDK-8160310 HotSpot cannot be built with GCC 6

          • P3 - Major loss of function.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8202171 Some oopDesc functions compare this with NULL

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8244538 Undefined behaviour in JDK 8u HotSpot

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

            Activity

              People

              Assignee:
              coleenp Coleen Phillimore
              Reporter:
              kbarrett Kim Barrett
              Votes:
              0 Vote for this issue
              Watchers:
              5 Start watching this issue

                Dates

                Created:
                Updated:
                Resolved: