Hi Arnd, Arnd Bergmann <arnd@xxxxxxxx> writes: > The IPC system call handling is highly inconsistent across architectures, > some use sys_ipc, some use separate calls, and some use both. We also > have some architectures that require passing IPC_64 in the flags, and > others that set it implicitly. > > For the additon of a y2083 safe semtimedop() system call, I chose to only > support the separate entry points, but that requires first supporting > the regular ones with their own syscall numbers. > > The IPC_64 is now implied by the new semctl/shmctl/msgctl system > calls even on the architectures that require passing it with the ipc() > multiplexer. > > I'm not adding the new semtimedop() or semop() on 32-bit architectures, > those will get implemented using the new semtimedop_time64() version > that gets added along with the other time64 calls. > Three 64-bit architectures (powerpc, s390 and sparc) get semtimedop(). > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > One aspect here that might be a bit controversial is the use of > the same system call numbers across all architectures, synchronizing > all of them with the x86-32 numbers. With the new syscall.tbl > files, I hope we can just keep doing that in the future, and no > longer require the architecture maintainers to assign a number. > > This is mainly useful for implementers of the C libraries: if > we can add future system calls everywhere at the same time, using > a particular version of the kernel headers also guarantees that > the system call number macro is visible. > --- > 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. > 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. cheers
