Re: [PATCH v3 7/7] ia64: wire up system calls

[Firoz Khan]

Hi Arnd,

On Thu, 11 Oct 2018 at 12:55, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Thu, Oct 11, 2018 at 6:26 AM Firoz Khan <firoz.khan@xxxxxxxxxx> wrote:
> >
> > wire up perf_event_open, seccomp, pkey_mprotect, pkey_alloc,
> > pkey_free, statx, io_pgetevents and rseq system calls
> >
> > This require an architecture specific implementation as it not
> > present now.
> >
> > Signed-off-by: Firoz Khan <firoz.khan@xxxxxxxxxx>
> > ---
> >  arch/ia64/kernel/syscalls/syscall.tbl | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >
> > diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
> > index 6b64f60..1f42b60 100644
> > --- a/arch/ia64/kernel/syscalls/syscall.tbl
> > +++ b/arch/ia64/kernel/syscalls/syscall.tbl
> > @@ -335,3 +335,19 @@
> >  323     common  copy_file_range                 sys_copy_file_range
> >  324     common  preadv2                         sys_preadv2
> >  325     common  pwritev2                        sys_pwritev2
> > +# perf_event_open requires an architecture specific implementation
> > +326    common  perf_event_open                 sys_perf_event_open
> > +# seccomp requires an architecture specific implementation
> > +327    common  seccomp                         sys_seccomp
>
> I don't think that's correct for these two. perf_event_open() of
> course requires 'perf' support that ia64 does not have, but
> at least seccomp should just work.
>
> > +# pkey_mprotect requires an architecture specific implementation
> > +328    common  pkey_mprotect                   sys_pkey_mprotect
> > +# pkey_alloc requires an architecture specific implementation
> > +329    common  pkey_alloc                      sys_pkey_alloc
> > +# pkey_free requires an architecture specific implementation
> > +330    common  pkey_free                       sys_pkey_free
>
> One comment for all pkey calls would be sufficient. More importantly
> it requires hardware support that ia64 does not have AFAICT.
>
> > +# statx requires an architecture specific implementation
> > +331    common  statx                           sys_statx
> > +# io_pgetevents requires an architecture specific implementation
> > +332    common  io_pgetevents                   sys_io_pgetevents
>
> It certainly does not require any support from the architecture for these.
>
> > +# rseq requires an architecture specific implementation
> > +333    common  rseq                            sys_rseq
>
> Maybe leave rseq and pkey_* commented out so we reserve
> the number but don't add it for real? Maybe the ia64 maintainers
> have a preference.
>
> As asm-generic maintainer, I'd like to have the various asm/unistd.h
> headers be as similar as possible and at least reserve all the
> numbers even if we don't need the calls on a given architecture.
>

Thanks for your review.

Firoz

>        Arnd