OpenSSL and panama-foreign

[Maurizio Cimadamore]

I think I managed to figure out what introduced the regression.

Basically, it's down to the removal of customization for upcall stubs.

```

@@ -123,7 +120,7 @@ public static UpcallHandler make(ABIDescriptor abi, MethodHandle target, Calling
                  .anyMatch(s -> abi.arch.isStackType(s.type()));
          if (USE_INTRINSICS && isSimple && !usesStackArgs && supportsOptimizedUpcalls()) {
              checkPrimitive(doBindings.type());
-            JLI.ensureCustomized(doBindings);
+            doBindings = insertArguments(exactInvoker(doBindings.type()), 0, doBindings);
              VMStorage[] args = Arrays.stream(argMoves).map(Binding.Move::storage).toArray(VMStorage[]::new);
              VMStorage[] rets = Arrays.stream(retMoves).map(Binding.Move::storage).toArray(VMStorage[]::new);
              CallRegs conv = new CallRegs(args, rets);

```

If this patch is reverted, then everything works as expected (I've run 
your `ab` test 10 consecutive times, no crashes). Which seems like a 
latent bug in the upcall machinery.

That said, I think that, for the time being, it would be best to revert 
this code to what it was in 17, to avoid these spurious crashes.

I wonder if the reason behind the issue we're seeing is caused by the 
Addressable vs. MemoryAddress mismatch in the method type - e.g. maybe 
`exactInvoker(doBindings.type())` doesn't do what we think it should. 
I'll keep investigating tomorrow (well, later today :-) ).

Cheers
Maurizio

On 10/11/2021 22:38, Maurizio Cimadamore wrote:
> And, on this same vein, even with the resource scope handshake 
> disabled, Tomcat still crashes with the following Java option:
>
> export JAVA_OPTS="-XX:+DeoptimizeALot 
> --enable-native-access=ALL-UNNAMED --add-modules jdk.incubator.foreign"
>
> DeoptimizeALot causes frequent deopt events in the VM. The handshake 
> we use for shared segments also used deopt events. Something got 
> broken here and the upcall intrinsic doesn't seem to be able to handle 
> deopt events.
>
> Maurizio
>
>
> On 10/11/2021 22:27, Maurizio Cimadamore wrote:
>> This seems to point at some issues with the shared scope logic 
>> interacting badly with upcall intrinsics. But neither areas have 
>> changed significantly since 17, which makes this very odd.