# Re: \[PATCH 2/2\] arch: Reserve map\_shadow\_stack() syscall number for all architectures

- From: Edgecombe, Rick P \<rick.p.edgecombe@intel.com\>
- Date: 2023-09-11 23:20:23 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2023/09/2330306
- Thread: https://ratatoskr.run/linux-arch/2023/09/2330284/t.md

```text
On Mon, 2023-09-11 at 18:02 +0000, Sohil Mehta wrote:
> diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl
> b/arch/powerpc/kernel/syscalls/syscall.tbl
> index 20e50586e8a2..2767b8a42636 100644
> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
> @@ -539,3 +539,4 @@
>  450    nospu   set_mempolicy_home_node         sys_set_mempolicy_hom
> e_node
>  451    common  cachestat                       sys_cachestat
>  452    common  fchmodat2                       sys_fchmodat2
> +453    common  map_shadow_stack                sys_map_shadow_stack

I noticed in powerpc, the not implemented syscalls are manually mapped
to sys_ni_syscall. It also has some special extra sys_ni_syscall()
implementation bits to handle both ARCH_HAS_SYSCALL_WRAPPER and
!ARCH_HAS_SYSCALL_WRAPPER. So wondering if it might need special
treatment. Did you see those parts?

```