Re: [PATCH 14/15] arch: add split IPC system calls where needed

[Michael Ellerman]

Arnd Bergmann <arnd@xxxxxxxx> writes:
> On Mon, Jan 14, 2019 at 4:59 AM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
>> Arnd Bergmann <arnd@xxxxxxxx> writes:
>> >  arch/m68k/kernel/syscalls/syscall.tbl     | 11 +++++++++++
>> >  arch/mips/kernel/syscalls/syscall_o32.tbl | 11 +++++++++++
>> >  arch/powerpc/kernel/syscalls/syscall.tbl  | 12 ++++++++++++
>>
>> I have some changes I'd like to make to our syscall table that will
>> clash with this.
>>
>> I'll try and send them today.
>
> Ok. Are those for 5.0 or 5.1? If they are intended for 5.0, it would be
> nice for me to have a branch based on 5.0-rc1 that I can put
> the other patches on top of.

For 5.1.

I can put them in a topic branch for you.

>> > diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
>> > index db3bbb8744af..1bffab54ff35 100644
>> > --- a/arch/powerpc/kernel/syscalls/syscall.tbl
>> > +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
>> > @@ -425,3 +425,15 @@
>> >  386  nospu   pkey_mprotect                   sys_pkey_mprotect
>> >  387  nospu   rseq                            sys_rseq
>> >  388  nospu   io_pgetevents                   sys_io_pgetevents               compat_sys_io_pgetevents
>> > +# room for arch specific syscalls
>> > +392  64      semtimedop                      sys_semtimedop
>> > +393  common  semget                          sys_semget
>> > +394  common  semctl                          sys_semctl                      compat_sys_semctl
>> > +395  common  shmget                          sys_shmget
>> > +396  common  shmctl                          sys_shmctl                      compat_sys_shmctl
>> > +397  common  shmat                           sys_shmat                       compat_sys_shmat
>> > +398  common  shmdt                           sys_shmdt
>> > +399  common  msgget                          sys_msgget
>> > +400  common  msgsnd                          sys_msgsnd                      compat_sys_msgsnd
>> > +401  common  msgrcv                          sys_msgrcv                      compat_sys_msgrcv
>> > +402  common  msgctl                          sys_msgctl                      compat_sys_msgctl
>>
>> We already have a gap at 366-377 from when we tried to add the split IPC
>> calls a few years back.
>>
>> I guess I don't mind leaving that gap and using the common numbers as
>> you've done here.
>>
>> But it would be good to add a comment pointing out that we have room
>> at 366 for more arch specific syscalls as well.
>
> Ah, I missed that. I've added this to my patch now:
>
> index 5c0936d862fc..2ddfba536d5f 100644
> --- a/arch/powerpc/kernel/syscalls/syscall.tbl
> +++ b/arch/powerpc/kernel/syscalls/syscall.tbl
> @@ -460,6 +460,7 @@
>  363    spu     switch_endian                   sys_ni_syscall
>  364    common  userfaultfd                     sys_userfaultfd
>  365    common  membarrier                      sys_membarrier
> +# 366-377 originally left for IPC, now unused
>  378    nospu   mlock2                          sys_mlock2
>  379    nospu   copy_file_range                 sys_copy_file_range
>  380    common  preadv2                         sys_preadv2
>          compat_sys_preadv2

Thanks.

cheers