[PATCH v4 00/10] Rework REFCOUNT_FULL using atomic_fetch_* operations

[Will Deacon]

Hi all,

This is version four of the patches I previously posted here:

  v1: https://lkml.kernel.org/r/20190802101000.12958-1-will@xxxxxxxxxx
  v2: https://lkml.kernel.org/r/20190827163204.29903-1-will@xxxxxxxxxx
  v3: https://lkml.kernel.org/r/20191007154703.5574-1-will@xxxxxxxxxx

Changes since v3 include:

  - Add description of racy behaviour include/linux/refcount.h
  - Fix saturation behaviour in refcount_sub_and_test()
  - Added Acks and Tested-bys

Cheers,

Will

Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Elena Reshetova <elena.reshetova@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Hanjun Guo <guohanjun@xxxxxxxxxx>
Cc: Jan Glauber <jglauber@xxxxxxxxxxx>

--->8

Will Deacon (10):
  lib/refcount: Define constants for saturation and max refcount values
  lib/refcount: Ensure integer operands are treated as signed
  lib/refcount: Remove unused refcount_*_checked() variants
  lib/refcount: Move bulk of REFCOUNT_FULL implementation into header
  lib/refcount: Improve performance of generic REFCOUNT_FULL code
  lib/refcount: Move saturation warnings out of line
  lib/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
  refcount: Consolidate implementations of refcount_t
  lib/refcount: Remove unused 'refcount_error_report()' function
  drivers/lkdtm: Remove references to CONFIG_REFCOUNT_FULL

 arch/Kconfig                       |  21 ---
 arch/arm/Kconfig                   |   1 -
 arch/arm64/Kconfig                 |   1 -
 arch/s390/configs/debug_defconfig  |   1 -
 arch/x86/Kconfig                   |   1 -
 arch/x86/include/asm/asm.h         |   6 -
 arch/x86/include/asm/refcount.h    | 126 --------------
 arch/x86/mm/extable.c              |  49 ------
 drivers/gpu/drm/i915/Kconfig.debug |   1 -
 drivers/misc/lkdtm/refcount.c      |  11 +-
 include/linux/kernel.h             |   7 -
 include/linux/refcount.h           | 269 ++++++++++++++++++++++++-----
 kernel/panic.c                     |  11 --
 lib/refcount.c                     | 255 +++------------------------
 14 files changed, 257 insertions(+), 503 deletions(-)
 delete mode 100644 arch/x86/include/asm/refcount.h

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2.24.0.rc0.303.g954a862665-goog