On Thu, 28 Aug 2025 07:43:19 GMT, Aleksey Shipilev <sh...@openjdk.org> wrote:
> See the bug for more investigation. > > The symptom of the problem is apparent `SIGSEGV` in `dlerror`. We were able > to debug it to older glibc issue, which makes `dlerror` not thread-safe when > pthreads are not yet loaded. This bug seems to uniquely affect custom > launchers. We figured this is because custom launchers are not linked with > `pthread`. JLI seems to be avoiding this issue, because it does link with > `pthread`. Therefore the fix on the JDK side is to always link custom > launchers with `pthread`. > > Reproducing the issue is a bit awkward. It requires compiling with older GCC > (7.3.1 in my case), so that `libsimdsort` would not expose `avx2_sort` > symbol, so that compiler stub initialization sequence would get its own > erroneous `dlerror`, which would conflict inside of glibc. The compilations > with newer GCC (10, at very least) are not exposed to this. This is why the > issue is so elusive. But now that we understand it, we know this is a ticking > time bomb that can fire at any time in the future, once any concurrent thread > inside of VM gets a non-zero `dlerror` for whatever reason. > > Additional testing: > - [x] Linux AArch64 server fastdebug, `sun/management/jmxremote`, 100x, no > failures > - [x] Linux AArch64 server fastdebug, `tools/jpackage`, 20x, no failures Marked as reviewed by asemenyuk (Reviewer). ------------- PR Review: https://git.openjdk.org/jdk/pull/26978#pullrequestreview-3164899835
