[0/4] Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute

Message

Christophe Leroy Jan. 9, 2024, 12:14 p.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

Christophe Leroy (4):
  arm: ptdump: Rename CONFIG_DEBUG_WX to CONFIG_ARM_DEBUG_WX
  arm64, powerpc, riscv, s390, x86: Refactor CONFIG_DEBUG_WX
  powerpc,s390: Define ptdump_check_wx() regardless of CONFIG_DEBUG_WX
  ptdump: add check_wx_pages debugfs attribute

 arch/arm/Kconfig.debug          |  2 +-
 arch/arm/include/asm/ptdump.h   |  6 +++---
 arch/arm64/include/asm/ptdump.h |  7 -------
 arch/arm64/mm/mmu.c             |  2 --
 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 | 10 ++++++----
 arch/riscv/include/asm/ptdump.h | 22 ----------------------
 arch/riscv/mm/init.c            |  3 ---
 arch/riscv/mm/ptdump.c          |  1 -
 arch/s390/include/asm/ptdump.h  | 14 --------------
 arch/s390/mm/dump_pagetables.c  |  8 ++------
 arch/s390/mm/init.c             |  2 --
 arch/x86/include/asm/pgtable.h  |  3 +--
 arch/x86/mm/dump_pagetables.c   |  3 +++
 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                     | 19 +++++++++++++++++++
 21 files changed, 44 insertions(+), 84 deletions(-)
 delete mode 100644 arch/riscv/include/asm/ptdump.h
 delete mode 100644 arch/s390/include/asm/ptdump.h