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  1. JDK
  2. JDK-8307817

AARCH64: make macOS W^X locking more fine grained

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Details

    • Enhancement
    • Resolution: Unresolved
    • P4
    • tbd
    • 21
    • hotspot
    • aarch64
    • os_x

    Description

      On Apple Silicon the Writer/Execute lock is a new Hardened Runtime capability, see:
      https://developer.apple.com/documentation/apple-silicon/porting-just-in-time-compilers-to-apple-silicon

      It prevents memory regions to be writable and executable at the same time. Therefore, we need to acquire WXWrite when we want to write to the code cache.

      At the moment, the write lock is acquired by
      ```
      MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, thread));
      ```

      Acquiring write lock can be expensive and is too coarse grained at the moment.
      Check all the write lock if they can be move down in the call hierarchy, especially the ones in `interfaceSupport.inline.hpp`

      In https://bugs.openjdk.org/browse/JDK-8302736 WXWrite locks caused a major performance regression and was resolved by moving one of the locks already down.

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        Issue Links

          relates to

          Enhancement - null JDK-8329748 Change default value of AssertWXAtThreadSync to true

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

          Sub-task - The sub-task of the issue JDK-8253816 Support macOS W^X

          • P2 - Crashes, loss of data, severe memory leak.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8302736 Major performance regression in Math.log on aarch64

          • P3 - Major loss of function.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. JDK-8316392 compiler/interpreter/TestVerifyStackAfterDeopt.java failed with SIGBUS in PcDescContainer::find_pc_desc_internal

          • P2 - Crashes, loss of data, severe memory leak.
          • Closed

          Enhancement - null JDK-8330171 Lazy W^X switch implementation

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

          Enhancement - null JDK-8331978 AARCH64: don't use MAP_JIT for stubs like f2hf and hf2f

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

          Enhancement - null JDK-8328306 Allow VM to run with X memory execute by default

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

          Enhancement - null JDK-8263492 [macos_aarch64] Consider moving W^X state to JavaThread

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

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            People

              dlong Dean Long
              tholenstein Tobias Holenstein
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              Dates

                Created:
                Updated: