Re: [PATCH v4 0/1] MR8073: ntdll: Unbreak new wow64 mode on FreeBSD.

[Alexandre Julliard (＠julliard)]

Alexandre Julliard (@julliard) commented about dlls/ntdll/unix/signal_x86_64.c:
>                 __ASM_CFI(".cfi_remember_state\n\t")
>                 __ASM_CFI_CFA_IS_AT2(rcx, 0xa8, 0x01) /* frame->syscall_cfa */
>                 "leaq 0x70(%rcx),%rsp\n\t"      /* %rsp > frame means no longer inside syscall */
>
> -#ifdef __linux__
> +#if defined(__linux__) || defined(__FreeBSD__)
>                     "testl $4,%r14d\n\t"            /* SYSCALL_HAVE_PTHREAD_TEB */
>                     "jz 1f\n\t"
>                     "movw 0x338(%r13),%fs\n"        /* amd64_thread_data()->fs */
> +# ifdef __FreeBSD__
> -
>               /* reset %ss (after sysret) for AMD */
> -
>               "movw $0x3b,%r14w\n\t"          /* GSEL(GUDATA_SEL, SEL_UPL) */
> -
>               "movw %r14w,%ss\n\t"
>
> +# endif

I don't think you should be changing %r14 here. It's also not clear why resetting %ss is necessary, where does it get cleared?