[RFC6,v6,00/21] ILP32 for ARM64

This version is rebased on kernel v4.6-rc2, and has fixes in signal subsystem.
It works with updated glibc [1] (though very draft), and tested with LTP.

It was tested on QEMU and ThunderX machines. No major difference found.
This is RFC because ILP32 is not tested in big-endian mode.

 v3: https://lkml.org/lkml/2014/9/3/704
 v4: https://lkml.org/lkml/2015/4/13/691
 v5: https://lkml.org/lkml/2015/9/29/911

 v6:
 - time_t, __kenel_off_t and other types turned to be 32-bit
   for compatibility reasons (after v5 discussion);
 - related changes applied to ILP32 syscall table and handlers;
 - ILP32 VDSO code excluded. It's not mandatory, and caused questions
   during review process. We definitely make sure we will follow up
   with a VDSO later on because it is needed for performance reasons;
 - fixed build issues with different combinations of AARCH32 / ILP32
   enabling in config;
 - ILP32 TLS bug fixed;
 - entry32-common.S introduced to hold wrappers needed for both ILP32
   and AARCH32_EL0;
 - documentation updated according to latest changes;
 - rebased to the current head;
 - coding style re-checked;
 - ILP32 syscall table turned around.

   rfc3:
 - all structures and system calls are just like AARCH32 ones now. with 2
   exceptions: syscalls that take 64-bit parameter in 2 32-bit regosters
   are replaced with LP64 version; struct rt_sigframe is constructed both
   from LP64 and AARCH32 fields to be consistent with AARCH64 register set;
 - documentation rewritten accordingly;
 - common code for all 3 ABIs is moved to separated files for easy use,
   new headers and objects are introduced, incl: is_compat.h, thread_bits.h,
   signal_common.h, signal32_common.h.
 - ILP32 VDSO code restored, Nathans comments are addressed;
 - patch "arm64: ilp32: force IPC_64 in msgctl, shmctl, semctl" removed, as
   Arnd suggested general solution for IPC_64 problem.

   rfc4:
 - sys_ilp32.c syscall list is fixed according to comments;
 - binfmt_elf32.c and binfmt_ilp32.c are introduced to host the code handling
   corresponding formats;
 - statfs64, fstsatfs64 and mmap wrappers are removed;
 - rebased on v4.4-rc8 + http://www.spinics.net/lists/kernel/msg2151759.html

 rfc5:
 - addressed rfc4 comments;
 - turned s390 compat wrappers to be generic and applied it to arm64/ilp32.
   Heiko Carsten and Martin Schwidefsky added to CC as s390 maintainers.

 rfc6:
 - glibc follows new ABI, [1];
 - significant rework for signal subsystem (patches 21, 23) - struct ucontext
   is now corresponds user representation;
 - compat wrappers and 32-bit off_t patchsets are joined with this patchset,
   as for now ilp32 is the only user for them;
 - moved to kernel v4.6-rc2;
 - few minor bugfixes.

[1] https://github.com/norov/glibc/tree/new-api

Andrew Pinski (7):
  arm64: ensure the kernel is compiled for LP64
  arm64: rename COMPAT to AARCH32_EL0 in Kconfig
  arm64: change some CONFIG_COMPAT over to use CONFIG_AARCH32_EL0
    instead
  arm64:uapi: set __BITS_PER_LONG correctly for ILP32 and LP64
  arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use
    it
  arm64: ilp32: introduce ilp32-specific handlers for sigframe and
    ucontext
  arm64:ilp32: add ARM64_ILP32 to Kconfig

Bamvor Jian Zhang (1):
  arm64: compat: change config dependences to aarch32

Philipp Tomsich (1):
  arm64:ilp32: add vdso-ilp32 and use for signal return

Yury Norov (16):
  all: syscall wrappers: add documentation
  all: introduce COMPAT_WRAPPER option and enable it for s390
  all: s390: move wrapper infrastructure to generic headers
  all: s390: move compat_wrappers.c from arch/s390/kernel to kernel/
  all: wrap needed syscalls in generic unistd
  compat ABI: use non-compat openat and open_by_handle_at variants
  32-bit ABI: introduce ARCH_32BIT_OFF_T config option
  arm64: ilp32: add documentation on the ILP32 ABI for ARM64
  thread: move thread bits accessors to separated file
  arm64: introduce is_a32_task and is_a32_thread (for AArch32 compat)
  arm64: ilp32: add is_ilp32_compat_{task,thread} and TIF_32BIT_AARCH64
  arm64: introduce binfmt_elf32.c
  arm64: ilp32: introduce binfmt_ilp32.c
  arm64: ptrace: handle ptrace_request differently for aarch32 and ilp32
  arm64: signal: share lp64 signal routines to ilp32
  arm64: signal32: move ilp32 and aarch32 common code to separated file

 Documentation/adding-syscalls.txt             |  32 +++
 Documentation/arm64/ilp32.txt                 |  13 ++
 arch/Kconfig                                  |   8 +
 arch/arc/Kconfig                              |   1 +
 arch/arm/Kconfig                              |   1 +
 arch/arm64/Kconfig                            |  17 +-
 arch/arm64/Makefile                           |   5 +
 arch/arm64/include/asm/compat.h               |  19 +-
 arch/arm64/include/asm/elf.h                  |  35 +---
 arch/arm64/include/asm/fpsimd.h               |   2 +-
 arch/arm64/include/asm/ftrace.h               |   2 +-
 arch/arm64/include/asm/hwcap.h                |   6 +-
 arch/arm64/include/asm/is_compat.h            |  84 ++++++++
 arch/arm64/include/asm/memory.h               |   3 +-
 arch/arm64/include/asm/processor.h            |  11 +-
 arch/arm64/include/asm/ptrace.h               |   2 +-
 arch/arm64/include/asm/signal32.h             |   6 +-
 arch/arm64/include/asm/signal32_common.h      |  25 +++
 arch/arm64/include/asm/signal_common.h        |  33 +++
 arch/arm64/include/asm/signal_ilp32.h         |  34 ++++
 arch/arm64/include/asm/syscall.h              |   2 +-
 arch/arm64/include/asm/thread_info.h          |   3 +-
 arch/arm64/include/asm/unistd.h               |  11 +-
 arch/arm64/include/asm/unistd32.h             |   2 +-
 arch/arm64/include/asm/vdso.h                 |   6 +
 arch/arm64/include/uapi/asm/bitsperlong.h     |   9 +-
 arch/arm64/kernel/Makefile                    |  12 +-
 arch/arm64/kernel/asm-offsets.c               |   2 +-
 arch/arm64/kernel/binfmt_elf32.c              |  33 +++
 arch/arm64/kernel/binfmt_ilp32.c              |  91 +++++++++
 arch/arm64/kernel/cpufeature.c                |   8 +-
 arch/arm64/kernel/cpuinfo.c                   |   4 +-
 arch/arm64/kernel/entry.S                     |  18 +-
 arch/arm64/kernel/entry_ilp32.S               |  23 +++
 arch/arm64/kernel/head.S                      |   2 +-
 arch/arm64/kernel/hw_breakpoint.c             |  10 +-
 arch/arm64/kernel/perf_regs.c                 |   2 +-
 arch/arm64/kernel/process.c                   |   7 +-
 arch/arm64/kernel/ptrace.c                    |  67 ++++++-
 arch/arm64/kernel/signal.c                    | 100 ++++++----
 arch/arm64/kernel/signal32.c                  |  85 --------
 arch/arm64/kernel/signal32_common.c           | 115 +++++++++++
 arch/arm64/kernel/signal_ilp32.c              | 192 ++++++++++++++++++
 arch/arm64/kernel/sys32.c                     |   1 +
 arch/arm64/kernel/sys_ilp32.c                 |  68 +++++++
 arch/arm64/kernel/traps.c                     |   5 +-
 arch/arm64/kernel/vdso-ilp32/.gitignore       |   2 +
 arch/arm64/kernel/vdso-ilp32/Makefile         |  72 +++++++
 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S     |  33 +++
 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S |  95 +++++++++
 arch/arm64/kernel/vdso.c                      |  65 ++++--
 arch/blackfin/Kconfig                         |   1 +
 arch/cris/Kconfig                             |   1 +
 arch/frv/Kconfig                              |   1 +
 arch/h8300/Kconfig                            |   1 +
 arch/hexagon/Kconfig                          |   1 +
 arch/m32r/Kconfig                             |   1 +
 arch/m68k/Kconfig                             |   1 +
 arch/metag/Kconfig                            |   1 +
 arch/microblaze/Kconfig                       |   1 +
 arch/mips/Kconfig                             |   1 +
 arch/mn10300/Kconfig                          |   1 +
 arch/nios2/Kconfig                            |   1 +
 arch/openrisc/Kconfig                         |   1 +
 arch/parisc/Kconfig                           |   1 +
 arch/powerpc/Kconfig                          |   1 +
 arch/s390/Kconfig                             |   1 +
 arch/s390/include/asm/compat.h                |  17 +-
 arch/s390/kernel/Makefile                     |   2 +-
 arch/s390/kernel/compat_linux.c               |   4 +
 arch/s390/kernel/compat_wrapper.c             | 180 -----------------
 arch/score/Kconfig                            |   1 +
 arch/sh/Kconfig                               |   1 +
 arch/sparc/Kconfig                            |   1 +
 arch/tile/Kconfig                             |   1 +
 arch/tile/kernel/compat.c                     |   3 +
 arch/unicore32/Kconfig                        |   1 +
 arch/x86/Kconfig                              |   1 +
 arch/x86/um/Kconfig                           |   1 +
 arch/xtensa/Kconfig                           |   1 +
 drivers/clocksource/arm_arch_timer.c          |   2 +-
 include/linux/compat.h                        | 277 ++++++++++++++++++++++++++
 include/linux/fcntl.h                         |   2 +-
 include/linux/ptrace.h                        |   6 +
 include/linux/syscalls.h                      |  57 +-----
 include/linux/syscalls_structs.h              |  60 ++++++
 include/linux/thread_bits.h                   |  55 +++++
 include/linux/thread_info.h                   |  44 +---
 include/uapi/asm-generic/unistd.h             | 231 ++++++++++-----------
 kernel/Makefile                               |   1 +
 kernel/compat_wrapper.c                       | 175 ++++++++++++++++
 kernel/ptrace.c                               |  10 +-
 92 files changed, 1997 insertions(+), 637 deletions(-)
 create mode 100644 Documentation/arm64/ilp32.txt
 create mode 100644 arch/arm64/include/asm/is_compat.h
 create mode 100644 arch/arm64/include/asm/signal32_common.h
 create mode 100644 arch/arm64/include/asm/signal_common.h
 create mode 100644 arch/arm64/include/asm/signal_ilp32.h
 create mode 100644 arch/arm64/kernel/binfmt_elf32.c
 create mode 100644 arch/arm64/kernel/binfmt_ilp32.c
 create mode 100644 arch/arm64/kernel/entry_ilp32.S
 create mode 100644 arch/arm64/kernel/signal32_common.c
 create mode 100644 arch/arm64/kernel/signal_ilp32.c
 create mode 100644 arch/arm64/kernel/sys_ilp32.c
 create mode 100644 arch/arm64/kernel/vdso-ilp32/.gitignore
 create mode 100644 arch/arm64/kernel/vdso-ilp32/Makefile
 create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.S
 create mode 100644 arch/arm64/kernel/vdso-ilp32/vdso-ilp32.lds.S
 delete mode 100644 arch/s390/kernel/compat_wrapper.c
 create mode 100644 include/linux/syscalls_structs.h
 create mode 100644 include/linux/thread_bits.h
 create mode 100644 kernel/compat_wrapper.c

-- 
2.5.0