On Thu, 11 Nov 2021 18:07:37 GMT, Andrew Haley <a...@openjdk.org> wrote:
> > > Am I right is saying that for Macos, all generated code is remapped RO > > > before execution? > > > > > > Ah, no, it seems the code cache is not RWX all the time as far as Java > > threads are concerned. The Macos/AArch64 code is strategically calling > > pthread_jit_write_protect_np at Java <-> JVM transition points. > > And this requires magic kernel support. I did mention it to a kernel engineer > who wasn't very impressed, but I think it's pretty cool. It's possible to emulate this to some extent with memory protection keys on POWER and (recent) x86. See `pkey_alloc`. ------------- PR: https://git.openjdk.java.net/jdk/pull/6334
