[v2,0/5] mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute

Message

Christophe Leroy Jan. 30, 2024, 10:34 a.m. UTC

Refer old discussion at https://lore.kernel.org/lkml/20200422152656.GF676@willie-the-truck/T/#m802eaf33efd6f8d575939d157301b35ac0d4a64f
And https://github.com/KSPP/linux/issues/35

This series refactors CONFIG_DEBUG_WX for the 5 architectures
implementing CONFIG_GENERIC_PTDUMP

First rename stuff in ARM which uses similar names while not
implementing CONFIG_GENERIC_PTDUMP.

Then define a generic version of debug_checkwx() that calls
ptdump_check_wx() when CONFIG_DEBUG_WX is set. Call it immediately
after calling mark_rodata_ro() instead of calling it at the end of
every mark_rodata_ro().

Then implement a debugfs attribute that can be used to trigger
a W^X test at anytime and regardless of CONFIG_DEBUG_WX

Changes in v2:
- Fixed a few build failures (patch 1 and 2)
- Added patch 4
- Make the attribute return SUCCESS/FAILURE as suggested by Heiko (patch 5)

Christophe Leroy (5):
  arm: ptdump: Rename CONFIG_DEBUG_WX to CONFIG_ARM_DEBUG_WX
  arm64, powerpc, riscv, s390, x86: ptdump: Refactor CONFIG_DEBUG_WX
  powerpc,s390: ptdump: Define ptdump_check_wx() regardless of
    CONFIG_DEBUG_WX
  mm: ptdump: Have ptdump_check_wx() return bool
  mm: ptdump: add check_wx_pages debugfs attribute

 arch/arm/Kconfig.debug               |  2 +-
 arch/arm/configs/aspeed_g4_defconfig |  2 +-
 arch/arm/configs/aspeed_g5_defconfig |  2 +-
 arch/arm/include/asm/ptdump.h        |  6 +++---
 arch/arm/mm/init.c                   |  2 +-
 arch/arm64/include/asm/ptdump.h      |  7 -------
 arch/arm64/mm/mmu.c                  |  2 --
 arch/arm64/mm/ptdump.c               | 11 ++++++++---
 arch/powerpc/mm/mmu_decl.h           |  6 ------
 arch/powerpc/mm/pgtable_32.c         |  4 ----
 arch/powerpc/mm/pgtable_64.c         |  3 ---
 arch/powerpc/mm/ptdump/ptdump.c      | 21 ++++++++++++++-------
 arch/riscv/include/asm/ptdump.h      | 22 ----------------------
 arch/riscv/mm/init.c                 |  3 ---
 arch/riscv/mm/ptdump.c               | 12 ++++++++----
 arch/s390/include/asm/ptdump.h       | 14 --------------
 arch/s390/mm/dump_pagetables.c       | 21 +++++++++++----------
 arch/s390/mm/init.c                  |  2 --
 arch/x86/include/asm/pgtable.h       |  5 ++---
 arch/x86/mm/dump_pagetables.c        | 20 ++++++++++++++------
 arch/x86/mm/init_32.c                |  2 --
 arch/x86/mm/init_64.c                |  2 --
 include/linux/ptdump.h               |  7 +++++++
 init/main.c                          |  2 ++
 mm/ptdump.c                          | 22 ++++++++++++++++++++++
 25 files changed, 95 insertions(+), 107 deletions(-)
 delete mode 100644 arch/riscv/include/asm/ptdump.h
 delete mode 100644 arch/s390/include/asm/ptdump.h