Subject: [PATCH v2 00/37] Implement execute-only protection on powerpc

From: Christophe Leroy <[email-masked]>
Date: Mon, 25 Sep 2023 20:31:14 +0200

This series reworks _PAGE_FLAGS on all platforms in order
to implement execute-only protection on all powerpc.

For all targets except 40x and 604 it will be a real execute-only
protection as the hardware and/or software allows a distinct protection.

For 40x and 604 that's a poor's man execute-only protection in the
way that once the page is in the TLB it can be executed. But it's
better than nothing and allows to have a similar implementation for
all sorts of powerpc.

Patches 1 and 2 are fixes that should also be back-ported to stable
version.

Patches 3 to 7 are generic trivial cleanups.

Patches 8 to 19 are a cleanup of pgtable.h for nohash. Main purpose
is to refactor a lot of common code between nohash/32 and nohash/64.

Patches 20 to 37 do the real work on PAGE flags in order to
switch all platforms to _PAGE_READ and _PAGE_WRITE like book3s/64
today. Once that is done it is easy to implement execute-only
protection.

Patch 1 to 19 were already sent-out as v1 of series
named "cleanup/refactor pgtable.h". Problems reported by robots
are fixed here.

Christophe Leroy (37):
  powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE
  powerpc/64e: Fix wrong test in __ptep_test_and_clear_young()
  powerpc/40x: Remove stale PTE_ATOMIC_UPDATES macro
  powerpc: Remove pte_ERROR()
  powerpc: Deduplicate prototypes of ptep_set_access_flags() and
    phys_mem_access_prot()
  powerpc: Refactor update_mmu_cache_range()
  powerpc: Untangle fixmap.h and pgtable.h and mmu.h
  powerpc/nohash: Remove {pte/pmd}_protnone()
  powerpc/nohash: Refactor declaration of {map/unmap}_kernel_page()
  powerpc/nohash: Move 8xx version of pte_update() into pte-8xx.h
  powerpc/nohash: Replace #ifdef CONFIG_44x by IS_ENABLED(CONFIG_44x) in
    pgtable.h
  powerpc/nohash: Refactor pte_update()
  powerpc/nohash: Refactor checking of no-change in pte_update()
  powerpc/nohash: Deduplicate _PAGE_CHG_MASK
  powerpc/nohash: Deduplicate pte helpers
  powerpc/nohash: Refactor ptep_test_and_clear_young()
  powerpc/nohash: Deduplicate ptep_set_wrprotect() and
    ptep_get_and_clear()
  powerpc/nohash: Refactor pte_clear()
  powerpc/nohash: Refactor __ptep_set_access_flags()
  powerpc/e500: Simplify pte_mkexec()
  powerpc: Implement and use pgprot_nx()
  powerpc: Fail ioremap() instead of silently ignoring flags when
    PAGE_USER is set
  powerpc: Remove pte_mkuser() and pte_mkpriviledged()
  powerpc: Rely on address instead of pte_user()
  powerpc: Refactor permission masks used for __P/__S table and kernel
    memory flags
  powerpc/8xx: Use generic permission masks
  powerpc/64s: Use generic permission masks
  powerpc/nohash: Add _PAGE_WRITE to supplement _PAGE_RW
  powerpc/nohash: Replace pte_user() by pte_read()
  powerpc/e500: Introduce _PAGE_READ and remove _PAGE_USER
  powerpc/44x: Introduce _PAGE_READ and remove _PAGE_USER
  powerpc/40x: Introduce _PAGE_READ and remove _PAGE_USER
  powerpc/32s: Add _PAGE_WRITE to supplement _PAGE_RW
  powerpc/32s: Introduce _PAGE_READ and remove _PAGE_USER
  powerpc/ptdump: Display _PAGE_READ and _PAGE_WRITE
  powerpc: Finally remove _PAGE_USER
  powerpc: Support execute-only on all powerpc

 arch/powerpc/include/asm/book3s/32/pgtable.h  |  83 +++----
 arch/powerpc/include/asm/book3s/64/pgtable.h  |  35 +--
 arch/powerpc/include/asm/book3s/pgtable.h     |  33 ---
 arch/powerpc/include/asm/fixmap.h             |  16 +-
 arch/powerpc/include/asm/nohash/32/mmu-8xx.h  |   1 -
 arch/powerpc/include/asm/nohash/32/pgtable.h  | 201 +---------------
 arch/powerpc/include/asm/nohash/32/pte-40x.h  |  21 +-
 arch/powerpc/include/asm/nohash/32/pte-44x.h  |  20 +-
 arch/powerpc/include/asm/nohash/32/pte-85xx.h |  20 +-
 arch/powerpc/include/asm/nohash/32/pte-8xx.h  |  99 +++++---
 arch/powerpc/include/asm/nohash/64/pgtable.h  | 120 +---------
 arch/powerpc/include/asm/nohash/pgtable.h     | 216 ++++++++++++------
 arch/powerpc/include/asm/nohash/pte-e500.h    |  41 +---
 arch/powerpc/include/asm/pgtable-masks.h      |  32 +++
 arch/powerpc/include/asm/pgtable.h            |  35 +++
 arch/powerpc/kernel/head_40x.S                |  19 +-
 arch/powerpc/kernel/head_44x.S                |  40 ++--
 arch/powerpc/kernel/head_85xx.S               |  12 +-
 arch/powerpc/kernel/head_book3s_32.S          |  63 ++---
 arch/powerpc/mm/book3s32/hash_low.S           |  32 ++-
 arch/powerpc/mm/book3s32/mmu.c                |   6 +-
 arch/powerpc/mm/book3s64/pgtable.c            |  10 +-
 arch/powerpc/mm/fault.c                       |   9 +-
 arch/powerpc/mm/init_32.c                     |   1 +
 arch/powerpc/mm/ioremap.c                     |   6 +-
 arch/powerpc/mm/mem.c                         |   1 +
 arch/powerpc/mm/nohash/40x.c                  |  19 +-
 arch/powerpc/mm/nohash/8xx.c                  |   2 +
 arch/powerpc/mm/nohash/book3e_pgtable.c       |   2 +-
 arch/powerpc/mm/nohash/e500.c                 |   6 +-
 arch/powerpc/mm/nohash/e500_hugetlbpage.c     |   3 +-
 arch/powerpc/mm/pgtable.c                     |  26 +--
 arch/powerpc/mm/ptdump/8xx.c                  |   5 -
 arch/powerpc/mm/ptdump/shared.c               |  14 +-
 arch/powerpc/platforms/83xx/misc.c            |   2 +
 arch/powerpc/platforms/8xx/cpm1.c             |   1 +
 36 files changed, 511 insertions(+), 741 deletions(-)
 create mode 100644 arch/powerpc/include/asm/pgtable-masks.h

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2.41.0