Re: [PATCH 0/4] MR6866: Draft: ntdll: On macOS x86_64, swap GSBASE between the TEB and macOS TSD when entering/leaving PE code.

[Brendan Shanks (＠bshanks)]

On Fri Nov 22 16:35:35 2024 +0000, Jinoh Kang wrote:
> Oh, if we're *completely* getting rid of `gs30` hack and following the
> same pattern as wrfsbase/movfs, then no handlers are confused and we're
> fine. Thanks for pointing that out. Sorry for confusion.

Ah I see, the key is "As long as you do it at the same place as the Linux case it should work fine". Right now in `__wine_syscall_dispatcher_return` I'm resetting GSBASE much earlier than the Linux %fs is set, since the `SYSCALL_HAVE_XSAVE` case accesses %gs.
Maybe the FP/xstate restore could be moved below the `%rsp > frame` line? Or `xstate_features_mask` could be stored in the syscall frame?