[00/14] clean up asm/uaccess.h, kill set_fs for good

From: Arnd Bergmann <arnd@arndb.de>

Christoph Hellwig and a few others spent a huge effort on removing
set_fs() from most of the important architectures, but about half the
other architectures were never completed even though most of them don't
actually use set_fs() at all.

I did a patch for microblaze at some point, which turned out to be fairly
generic, and now ported it to most other architectures, using new generic
implementations of access_ok() and __{get,put}_kernel_nocheck().

Three architectures (sparc64, ia64, and sh) needed some extra work,
which I also completed.

The final series contains extra cleanup changes that touch all
architectures. Please review and test these, so we can merge them
for v5.18.

The series is available at
https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=set_fs
for testing.

       Arnd

Arnd Bergmann (14):
  uaccess: fix integer overflow on access_ok()
  sparc64: add __{get,put}_kernel_nocheck()
  nds32: fix access_ok() checks in get/put_user
  x86: use more conventional access_ok() definition
  uaccess: add generic __{get,put}_kernel_nofault
  mips: use simpler access_ok()
  uaccess: generalize access_ok()
  arm64: simplify access_ok()
  m68k: drop custom __access_ok()
  uaccess: remove most CONFIG_SET_FS users
  sparc64: remove CONFIG_SET_FS support
  sh: remove CONFIG_SET_FS support
  ia64: remove CONFIG_SET_FS support
  uaccess: drop set_fs leftovers

 arch/Kconfig                              |   3 -
 arch/alpha/Kconfig                        |   1 -
 arch/alpha/include/asm/processor.h        |   4 -
 arch/alpha/include/asm/thread_info.h      |   2 -
 arch/alpha/include/asm/uaccess.h          |  53 +--------
 arch/arc/Kconfig                          |   1 -
 arch/arc/include/asm/segment.h            |  20 ----
 arch/arc/include/asm/thread_info.h        |   3 -
 arch/arc/include/asm/uaccess.h            |  30 -----
 arch/arm/include/asm/uaccess.h            |  22 +---
 arch/arm/kernel/swp_emulate.c             |   2 +-
 arch/arm/kernel/traps.c                   |   2 +-
 arch/arm/lib/uaccess_with_memcpy.c        |  10 --
 arch/arm64/include/asm/uaccess.h          |  29 +----
 arch/csky/Kconfig                         |   1 -
 arch/csky/include/asm/processor.h         |   2 -
 arch/csky/include/asm/segment.h           |  10 --
 arch/csky/include/asm/thread_info.h       |   2 -
 arch/csky/include/asm/uaccess.h           |  12 --
 arch/csky/kernel/asm-offsets.c            |   1 -
 arch/csky/kernel/signal.c                 |   2 +-
 arch/h8300/Kconfig                        |   1 -
 arch/h8300/include/asm/processor.h        |   1 -
 arch/h8300/include/asm/segment.h          |  40 -------
 arch/h8300/include/asm/thread_info.h      |   3 -
 arch/h8300/kernel/entry.S                 |   1 -
 arch/h8300/kernel/head_ram.S              |   1 -
 arch/h8300/mm/init.c                      |   6 -
 arch/h8300/mm/memory.c                    |   1 -
 arch/hexagon/Kconfig                      |   1 -
 arch/hexagon/include/asm/thread_info.h    |   6 -
 arch/hexagon/include/asm/uaccess.h        |  25 ----
 arch/hexagon/kernel/process.c             |   1 -
 arch/ia64/Kconfig                         |   1 -
 arch/ia64/include/asm/processor.h         |   4 -
 arch/ia64/include/asm/thread_info.h       |   2 -
 arch/ia64/include/asm/uaccess.h           |  26 ++---
 arch/ia64/kernel/unaligned.c              |  60 ++++++----
 arch/m68k/include/asm/uaccess.h           |  14 +--
 arch/microblaze/Kconfig                   |   1 -
 arch/microblaze/include/asm/thread_info.h |   6 -
 arch/microblaze/include/asm/uaccess.h     |  43 +------
 arch/microblaze/kernel/asm-offsets.c      |   1 -
 arch/microblaze/kernel/process.c          |   1 -
 arch/mips/include/asm/uaccess.h           |  47 +-------
 arch/nds32/Kconfig                        |   1 -
 arch/nds32/include/asm/thread_info.h      |   4 -
 arch/nds32/include/asm/uaccess.h          |  40 +++----
 arch/nds32/kernel/process.c               |   5 +-
 arch/nds32/mm/alignment.c                 |   3 -
 arch/nios2/Kconfig                        |   1 -
 arch/nios2/include/asm/thread_info.h      |   9 --
 arch/nios2/include/asm/uaccess.h          |  23 +---
 arch/nios2/kernel/signal.c                |  20 ++--
 arch/openrisc/Kconfig                     |   1 -
 arch/openrisc/include/asm/thread_info.h   |   7 --
 arch/openrisc/include/asm/uaccess.h       |  42 +------
 arch/parisc/include/asm/futex.h           |   2 +-
 arch/parisc/include/asm/uaccess.h         |  11 +-
 arch/parisc/lib/memcpy.c                  |   2 +-
 arch/powerpc/include/asm/uaccess.h        |  13 +--
 arch/powerpc/lib/sstep.c                  |   4 +-
 arch/riscv/include/asm/uaccess.h          |  33 +-----
 arch/riscv/kernel/perf_callchain.c        |   2 +-
 arch/s390/include/asm/uaccess.h           |  13 +--
 arch/sh/Kconfig                           |   1 -
 arch/sh/include/asm/processor.h           |   1 -
 arch/sh/include/asm/segment.h             |  33 ------
 arch/sh/include/asm/thread_info.h         |   2 -
 arch/sh/include/asm/uaccess.h             |  24 +---
 arch/sh/kernel/io_trapped.c               |   9 +-
 arch/sh/kernel/process_32.c               |   2 -
 arch/sh/kernel/traps_32.c                 |  30 +++--
 arch/sparc/Kconfig                        |   1 -
 arch/sparc/include/asm/processor_32.h     |   6 -
 arch/sparc/include/asm/processor_64.h     |   4 -
 arch/sparc/include/asm/switch_to_64.h     |   4 +-
 arch/sparc/include/asm/thread_info_64.h   |   4 +-
 arch/sparc/include/asm/uaccess.h          |   3 -
 arch/sparc/include/asm/uaccess_32.h       |  31 +----
 arch/sparc/include/asm/uaccess_64.h       | 135 +++++++++++++---------
 arch/sparc/kernel/process_32.c            |   2 -
 arch/sparc/kernel/process_64.c            |  12 --
 arch/sparc/kernel/signal_32.c             |   2 +-
 arch/sparc/kernel/traps_64.c              |   2 -
 arch/sparc/lib/NGmemcpy.S                 |   3 +-
 arch/sparc/mm/init_64.c                   |   3 -
 arch/um/include/asm/uaccess.h             |   7 +-
 arch/x86/include/asm/uaccess.h            |  44 ++-----
 arch/xtensa/Kconfig                       |   1 -
 arch/xtensa/include/asm/asm-uaccess.h     |  71 ------------
 arch/xtensa/include/asm/processor.h       |   7 --
 arch/xtensa/include/asm/thread_info.h     |   3 -
 arch/xtensa/include/asm/uaccess.h         |  26 +----
 arch/xtensa/kernel/asm-offsets.c          |   3 -
 drivers/hid/uhid.c                        |   2 +-
 drivers/scsi/sg.c                         |   5 -
 fs/exec.c                                 |   6 -
 include/asm-generic/access_ok.h           |  51 ++++++++
 include/asm-generic/uaccess.h             |  46 +-------
 include/linux/syscalls.h                  |   4 -
 include/linux/uaccess.h                   |  59 +++-------
 include/rdma/ib.h                         |   2 +-
 kernel/events/callchain.c                 |   4 -
 kernel/events/core.c                      |   3 -
 kernel/exit.c                             |  14 ---
 kernel/kthread.c                          |   5 -
 kernel/stacktrace.c                       |   3 -
 kernel/trace/bpf_trace.c                  |   4 -
 mm/maccess.c                              | 119 -------------------
 mm/memory.c                               |   8 --
 net/bpfilter/bpfilter_kern.c              |   2 +-
 112 files changed, 315 insertions(+), 1239 deletions(-)
 delete mode 100644 arch/arc/include/asm/segment.h
 delete mode 100644 arch/csky/include/asm/segment.h
 delete mode 100644 arch/h8300/include/asm/segment.h
 delete mode 100644 arch/sh/include/asm/segment.h
 create mode 100644 include/asm-generic/access_ok.h

On Mon, Feb 14, 2022 at 8:35 AM Arnd Bergmann <arnd@kernel.org> wrote:
>
> I did a patch for microblaze at some point, which turned out to be fairly
> generic, and now ported it to most other architectures, using new generic
> implementations of access_ok() and __{get,put}_kernel_nocheck().

Thanks for doing this.

Apart from the sparc64 issue with completely separate address spaces
(so access_ok() should always return true like Al pointed out), this
looks excellent to me.

Somebody should check that there aren't other cases like sparc64, but
let's merge this asap other than that.

              Linus