Hi Heiko and Martin,

As promised, I gave this a go and changed the SYSCALL_DEFINEx() infrastructure to always include the wrappers for doing the 31-bit argument conversion on s390 compat mode.

This does three main things:

- The UID16 rework saved a lot of duplicated code, and would probably make sense by itself, but is also required as we can no longer call sys_*() functions directly after the last step.

- Removing the compat_wrapper.c file is of course the main goal here, in order to remove the need to maintain the compat_wrapper.c file when new system calls get added. Unfortunately, this requires adding some complexity in syscall_wrapper.h, and trades a small reduction in source code lines for a small increase in binary size for unused wrappers.

- As an added benefit, the use of syscall_wrapper.h now makes it easy to change the syscall wrappers so they no longer see all user space register contents, similar to changes done in commits fa697140f9a2 ("syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls") and 4378a7d4be30 ("arm64: implement syscall wrappers"). I leave the actual implementation of this for you, if you want to do it later.

I did not test the changes at runtime, but I looked at the generated object code, which seems fine here and includes the same conversions as before.

Arnd

Arnd Bergmann (5): s390: open-code s390_personality syscall ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390 s390: use generic UID16 implementation s390: autogenerate compat syscall wrappers s390: remove compat_wrapper.c

arch/s390/Kconfig | 2 + arch/s390/include/asm/syscall_wrapper.h | 136 +++++++++++ arch/s390/include/uapi/asm/posix_types.h | 6 + arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/compat_linux.c | 235 +------------------ arch/s390/kernel/compat_wrapper.c | 186 --------------- arch/s390/kernel/entry.S | 4 +- arch/s390/kernel/sys_s390.c | 14 +- arch/s390/kernel/syscalls/syscall.tbl | 286 +++++++++++------------ include/linux/syscalls.h | 4 + ipc/syscall.c | 20 +- 11 files changed, 322 insertions(+), 573 deletions(-) create mode 100644 arch/s390/include/asm/syscall_wrapper.h delete mode 100644 arch/s390/kernel/compat_wrapper.c