Re: [PATCH RFC v7 00/24] pkeys-based page table hardening

[Kevin Brodsky <kevin.brodsky@arm.com>]

On 05/05/2026 18:05, Kevin Brodsky wrote:
> Kevin Brodsky (23):
>       mm: Introduce kpkeys
>       set_memory: Introduce set_memory_pkey() stub
>       arm64: mm: Enable overlays for all EL1 indirect permissions
>       arm64: Introduce por_elx_set_pkey_perms() helper
>       arm64: Implement asm/kpkeys.h using POE
>       arm64: set_memory: Implement set_memory_pkey()
>       arm64: Context-switch POR_EL1
>       arm64: Enable kpkeys
>       memblock: Move INIT_MEMBLOCK_* macros to header
>       mm: kpkeys: Introduce kpkeys_hardened_pgtables feature
>       mm: kpkeys: Protect regular page tables
>       mm: kpkeys: Introduce early page table allocator
>       mm: kpkeys: Protect vmemmap page tables
>       mm: kpkeys: Introduce hook for protecting static page tables
>       arm64: kpkeys: Implement arch_supports_kpkeys_early()
>       arm64: kpkeys: Support KPKEYS_CTX_PGTABLES
>       arm64: kpkeys: Ensure the linear map can be modified
>       arm64: kpkeys: Protect early page tables
>       arm64: kpkeys: Protect init_pg_dir
>       arm64: kpkeys: Guard page table writes
>       arm64: kpkeys: Batch KPKEYS_CTX_PGTABLES switches
>       arm64: kpkeys: Enable kpkeys_hardened_pgtables support
>       mm: Add basic tests for kpkeys_hardened_pgtables
>
> Yeoreum Yun (1):
>       arm64: Initialize POR_EL1 register on cpu_resume()
>
>  arch/arm64/Kconfig                        |   2 +
>  arch/arm64/include/asm/cpufeature.h       |  12 ++
>  arch/arm64/include/asm/kpkeys.h           |  76 ++++++++++++
>  arch/arm64/include/asm/pgtable-prot.h     |  16 +--
>  arch/arm64/include/asm/pgtable.h          |  66 +++++++++-
>  arch/arm64/include/asm/por.h              |  11 ++
>  arch/arm64/include/asm/processor.h        |   2 +
>  arch/arm64/include/asm/set_memory.h       |   4 +
>  arch/arm64/kernel/cpufeature.c            |   5 +-
>  arch/arm64/kernel/process.c               |   9 ++
>  arch/arm64/kernel/sleep.S                 |  12 ++
>  arch/arm64/mm/fault.c                     |   2 +
>  arch/arm64/mm/init.c                      |   1 +
>  arch/arm64/mm/mmu.c                       |  48 +++++---
>  arch/arm64/mm/pageattr.c                  |  29 ++++-
>  include/asm-generic/kpkeys.h              |  21 ++++
>  include/linux/kpkeys.h                    | 177 ++++++++++++++++++++++++++
>  include/linux/memblock.h                  |  11 ++
>  include/linux/mm.h                        |  14 ++-
>  include/linux/set_memory.h                |   7 ++
>  mm/Kconfig                                |   5 +
>  mm/Makefile                               |   2 +
>  mm/kpkeys_hardened_pgtables.c             | 180 +++++++++++++++++++++++++++
>  mm/memblock.c                             |  11 --
>  mm/sparse-vmemmap.c                       |  29 +++--
>  mm/tests/kpkeys_hardened_pgtables_kunit.c | 198 ++++++++++++++++++++++++++++++
>  security/Kconfig.hardening                |  24 ++++
>  27 files changed, 923 insertions(+), 51 deletions(-)

Sashiko has found quite a few issues, some of which are potentially
concerning. I'll address them in RFC v8 - no need to point me to them
until then.

- Kevin