[PATCH v2 1/2] Cygwin: cache IsWow64Process2 host arch in wincap.

[Corinna Vinschen]

Btw...

On Nov 25 11:21, Jeremy Drake via Cygwin-patches wrote:
> @@ -4617,14 +4617,12 @@ find_fast_cwd_pointer ()
>  static fcwd_access_t **
>  find_fast_cwd ()
>  {
> -  USHORT emulated, hosted;
>    fcwd_access_t **f_cwd_ptr;
> 
> -  /* First check if we're running in WOW64 on ARM64 emulating AMD64.  Skip
> +  /* First check if we're running on an ARM64 system.  Skip
>       fetching FAST_CWD pointer as long as there's no solution for finding
>       it on that system. */
> -  if (IsWow64Process2 (GetCurrentProcess (), &emulated, &hosted)
> -      && hosted == IMAGE_FILE_MACHINE_ARM64)
> +  if (wincap.host_machine () == IMAGE_FILE_MACHINE_ARM64)
>      return NULL;

We're doing this because nobody being able to debug ARM64 assembler came
up with a piece of code checking the ntdll assembler code to find the
address of the fast_cwd_pointer on ARM64.

You seem to have the knowledge and the means to do that, Jeremy.

Any fun tracking this down?


Thanks,
Corinna