On Wed, 11 Feb 2026 01:21:23 GMT, Yasumasa Suenaga <[email protected]> wrote:
> We've introduced new test TestJhsdbJstackMixedCore.java in > [JDK-8374482](https://bugs.openjdk.org/browse/JDK-8374482) to check mixed > jstack could unwind signal trampoline on Linux AMD64. However it did not work > with following error in some case. We saw it on Oracle Linux 8.10 > intermittently. > > > java.lang.NullPointerException: Cannot invoke > "sun.jvm.hotspot.debugger.Address.addOffsetTo(long)" because "this.cfa" is > null > at > jdk.hotspot.agent/sun.jvm.hotspot.debugger.linux.amd64.LinuxAMD64CFrame.getNextRSP(LinuxAMD64CFrame.java:143) > at > jdk.hotspot.agent/sun.jvm.hotspot.debugger.linux.amd64.LinuxAMD64CFrame.sender(LinuxAMD64CFrame.java:189) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.run(PStack.java:195) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.run(PStack.java:65) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.PStack.run(PStack.java:60) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.JStack.run(JStack.java:67) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:278) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.start(Tool.java:241) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.Tool.execute(Tool.java:134) > at jdk.hotspot.agent/sun.jvm.hotspot.tools.JStack.runWithArgs(JStack.java:90) > at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runJSTACK(SALauncher.java:306) > at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:507) > > > It was caused by incorrect calculation for virtual address alignment. It > exists before JDK-8374482. We aligned `base address + virtual address` in > ELF, but it should be aligned virtual address only. > > This fix works fine with the coredump which we saw the error in above, and > also it passed CI on Oracle Linux 8.10. > > Thanks a lot @plummercj for your help! This pull request has now been integrated. Changeset: a532e509 Author: Yasumasa Suenaga <[email protected]> URL: https://git.openjdk.org/jdk/commit/a532e509ed60f6e8bfd66cdc6973f4d9042bb056 Stats: 7 lines in 3 files changed: 0 ins; 2 del; 5 mod 8377395: serviceability/sa/TestJhsdbJstackMixedCore.java fails due to NPE because "because "this.cfa" is null" Reviewed-by: cjplummer, kevinw ------------- PR: https://git.openjdk.org/jdk/pull/29662
