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
--
2.20.0
