[0/9] ARM: remove set_fs callers and implementation

Message

Arnd Bergmann Sept. 7, 2020, 3:36 p.m. UTC

Hi Christoph, Russell,

As promised, here is my series to remove set_fs() from arch/arm based
on the architecture-independent patches.

I have tested the oabi-compat changes using the LTP tests for the three
modified syscalls using an Armv7 kernel and a Debian 5 OABI user space,
and I have lightly tested the get_kernel_nofault infrastructure by
loading the test_lockup.ko module after setting CONFIG_DEBUG_SPINLOCK.

Let me know if there is a more thorough test I should try.

Overall there is a bit of ugliness getting introduced in the oabi compat
code and for adding another code path for TUSER(). If anyone has a better
idea, I can try out a different way.

I assume these patches can go through Al's tree along with the
corresponding changes for other architectures, once Russell is happy
with them.

Please review.

     Arnd

[1] https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=arm-kill-set_fs

Arnd Bergmann (9):
  mm/maccess: fix unaligned copy_{from,to}_kernel_nofault
  ARM: traps: use get_kernel_nofault instead of set_fs()
  ARM: oabi-compat: add epoll_pwait handler
  ARM: syscall: always store thread_info->syscall
  ARM: oabi-compat: rework epoll_wait/epoll_pwait emulation
  ARM: oabi-compat: rework sys_semtimedop emulation
  ARM: oabi-compat: rework fcntl64() emulation
  ARM: uaccess: add __{get,put}_kernel_nofault
  ARM: uaccess: remove set_fs() implementation

 arch/arm/Kconfig                   |   1 -
 arch/arm/include/asm/ptrace.h      |   1 -
 arch/arm/include/asm/syscall.h     |  14 +++
 arch/arm/include/asm/thread_info.h |   4 -
 arch/arm/include/asm/uaccess-asm.h |   6 -
 arch/arm/include/asm/uaccess.h     | 169 ++++++++++++++-------------
 arch/arm/kernel/asm-offsets.c      |   3 +-
 arch/arm/kernel/entry-common.S     |  16 +--
 arch/arm/kernel/process.c          |   7 +-
 arch/arm/kernel/ptrace.c           |   4 +-
 arch/arm/kernel/signal.c           |   8 --
 arch/arm/kernel/sys_oabi-compat.c  | 180 ++++++++++++++++-------------
 arch/arm/kernel/traps.c            |  69 +++++------
 arch/arm/lib/copy_from_user.S      |   3 +-
 arch/arm/lib/copy_to_user.S        |   3 +-
 arch/arm/tools/syscall.tbl         |   2 +-
 fs/eventpoll.c                     |   5 +-
 include/linux/eventpoll.h          |  16 +++
 include/linux/syscalls.h           |   2 +
 ipc/sem.c                          |  84 +++++++++-----
 mm/maccess.c                       |  28 ++++-
 21 files changed, 338 insertions(+), 287 deletions(-)