Re: [PATCH 15/15] arch: add pkey and rseq syscall numbers everywhere

Heiko Carstens
2019-01-10T20:36:58Z

On Thu, Jan 10, 2019 at 05:24:35PM +0100, Arnd Bergmann wrote:
> Most architectures define system call numbers for the rseq and pkey system
> calls, even when they don't support the features, and perhaps never will.
>
> Only a few architectures are missing these, so just define them anyway
> for consistency. If we decide to add them later to one of these, the
> system call numbers won't get out of sync then.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
> index a1fbf15d53aa..ed08f114ee91 100644
> --- a/arch/s390/include/asm/unistd.h
> +++ b/arch/s390/include/asm/unistd.h
> @@ -11,9 +11,6 @@
> #include <asm/unistd_nr.h>
>
> #define __IGNORE_time
> -#define __IGNORE_pkey_mprotect
> -#define __IGNORE_pkey_alloc
> -#define __IGNORE_pkey_free
>
> #define __ARCH_WANT_NEW_STAT
> #define __ARCH_WANT_OLD_READDIR
> diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
> index 428cf512a757..f84ea364a302 100644
> --- a/arch/s390/kernel/syscalls/syscall.tbl
> +++ b/arch/s390/kernel/syscalls/syscall.tbl
> @@ -391,6 +391,9 @@
> 381 common kexec_file_load sys_kexec_file_load compat_sys_kexec_file_load
> 382 common io_pgetevents sys_io_pgetevents compat_sys_io_pgetevents
> 383 common rseq sys_rseq compat_sys_rseq
> +384 common pkey_alloc sys_pkey_alloc sys_pkey_alloc
> +385 common pkey_free sys_pkey_free sys_pkey_free
> +386 common pkey_mprotect sys_pkey_mprotect sys_pkey_mprotect

Since you only need/want the system call numbers, could you please
change these lines to:

> +384 common pkey_alloc - -
> +385 common pkey_free - -
> +386 common pkey_mprotect - -

Otherwise it _looks_ like we would need compat wrappers here as well,
even though all of them would just jump to sys_ni_syscall() in this
case. Making this explicit seems to better.