[v11,00/13] KASAN for powerpc/32

Message

Christophe Leroy April 26, 2019, 4:23 p.m. UTC

This series adds KASAN support to powerpc/32

32 bits tested on nohash/32 (8xx), book3s/32 (mpc832x ie 603) and qemu mac99

Changes in v11:
- Dropped book3e RFC part.
- Rebased on latest powerpc merge branch (b251649c77625b7ad4430e518dc0f1608be9edf4).
Main impact is in head_32.S do to the merge with KUAP functionnality
- Added a fix from Daniel in prom_init: changed a direct struct assignation by a memcpy in patch 5

Changes in v10:
- Prepended the patch which fixes boot on hash32
- Reduced ifdef mess related to CONFIG_CMDLINE in prom_init.c
- Fixed strings preparation macros for ppc64 build (Reported by Daniel)
- Fixed boot failure on hash32 when total amount of memory is above the initial amount mapped with BATs.
- Reordered stuff in kasan.h to have a smoother patch when adding 64bit Book3E
- Split the change to PAGE_READONLY out of the hash32 patch.
- Appended Daniel's series for 64bit Book3E (with a build failure fix and a few cosmetic changes)

Changes in v9:
- Fixed fixmap IMMR alignment issue on 8xx with KASAN enabled.
- Set up final shadow page tables before switching to the final hash table on hash32
- Using PAGE_READONLY instead of PAGE_KERNEL_RO on hash32
- Use flash_tlb_kernel_range() instead of flash_tlb_mm() which doesn't work for kernel on some subarches.
- use __set_pte_at() instead of pte_update() to install final page tables

Changes in v8:
- Fixed circular issue between pgtable.h and fixmap.h
- Added missing includes in ppc64 string files
- Fixed kasan string related macro names for ppc64.
- Fixed most checkpatch messages
- build tested on kisskb (http://kisskb.ellerman.id.au/kisskb/head/6e65827de2fe71d21682dafd9084ed2cc6e06d4f/)
- moved CONFIG_KASAN_SHADOW_OFFSET in Kconfig.debug

Changes in v7:
- split in several smaller patches
- prom_init now has its own string functions
- full deactivation of powerpc-optimised string functions when KASAN is active
- shadow area now at a fixed place on very top of kernel virtual space.
- Early static hash table for hash book3s/32.
- Full support of both inline and outline instrumentation for both hash and nohash ppc32
- Earlier full activation of kasan.

Changes in v6:
- Fixed oops on module loading (due to access to RO shadow zero area).
- Added support for hash book3s/32, thanks to Daniel's patch to differ KASAN activation.
- Reworked handling of optimised string functions (dedicated patch for it)
- Reordered some files to ease adding of book3e/64 support.

Changes in v5:
- Added KASAN_SHADOW_OFFSET in Makefile, otherwise we fallback to KASAN_MINIMAL
and some stuff like stack instrumentation is not performed
- Moved calls to kasan_early_init() in head.S because stack instrumentation
in machine_init was performed before the call to kasan_early_init()
- Mapping kasan_early_shadow_page RW in kasan_early_init() and
remaping RO later in kasan_init()
- Allocating a big memblock() for shadow area, falling back to PAGE_SIZE blocks in case of failure.

Changes in v4:
- Comments from Andrey (DISABLE_BRANCH_PROFILING, Activation of reports)
- Proper initialisation of shadow area in kasan_init()
- Panic in case Hash table is required.
- Added comments in patch one to explain why *t = *s becomes memcpy(t, s, ...)
- Call of kasan_init_tags()

Changes in v3:
- Removed the printk() in kasan_early_init() to avoid build failure (see https://github.com/linuxppc/issues/issues/218)
- Added necessary changes in asm/book3s/32/pgtable.h to get it work on powerpc 603 family
- Added a few KASAN_SANITIZE_xxx.o := n to successfully boot on powerpc 603 family

Changes in v2:
- Rebased.
- Using __set_pte_at() to build the early table.
- Worked around and got rid of the patch adding asm/page.h in asm/pgtable-types.h
    ==> might be fixed independently but not needed for this serie.

Christophe Leroy (13):
  powerpc/32: Move early_init() in a separate file
  powerpc: prepare string/mem functions for KASAN
  powerpc: remove CONFIG_CMDLINE #ifdef mess
  powerpc/prom_init: don't use string functions from lib/
  powerpc: don't use direct assignation during early boot.
  powerpc/32: use memset() instead of memset_io() to zero BSS
  powerpc/32: make KVIRT_TOP dependent on FIXMAP_START
  powerpc/32: prepare shadow area for KASAN
  powerpc: disable KASAN instrumentation on early/critical files.
  powerpc/32: Add KASAN support
  powerpc/32s: move hash code patching out of MMU_init_hw()
  powerpc/32s: set up an early static hash table for KASAN.
  powerpc/32s: map kasan zero shadow with PAGE_READONLY instead of
    PAGE_KERNEL_RO

 arch/powerpc/Kconfig                         |   7 +-
 arch/powerpc/Kconfig.debug                   |   5 +
 arch/powerpc/include/asm/book3s/32/pgtable.h |  13 +-
 arch/powerpc/include/asm/fixmap.h            |   5 +
 arch/powerpc/include/asm/kasan.h             |  40 +++++
 arch/powerpc/include/asm/nohash/32/pgtable.h |  13 +-
 arch/powerpc/include/asm/string.h            |  32 +++-
 arch/powerpc/kernel/Makefile                 |  14 +-
 arch/powerpc/kernel/cputable.c               |  13 +-
 arch/powerpc/kernel/early_32.c               |  36 +++++
 arch/powerpc/kernel/head_32.S                |  76 ++++++---
 arch/powerpc/kernel/head_40x.S               |   3 +
 arch/powerpc/kernel/head_44x.S               |   3 +
 arch/powerpc/kernel/head_8xx.S               |   3 +
 arch/powerpc/kernel/head_fsl_booke.S         |   3 +
 arch/powerpc/kernel/prom_init.c              | 228 +++++++++++++++++++++------
 arch/powerpc/kernel/prom_init_check.sh       |  12 +-
 arch/powerpc/kernel/setup-common.c           |   3 +
 arch/powerpc/kernel/setup_32.c               |  28 ----
 arch/powerpc/lib/Makefile                    |  19 ++-
 arch/powerpc/lib/copy_32.S                   |  12 +-
 arch/powerpc/lib/mem_64.S                    |   9 +-
 arch/powerpc/lib/memcpy_64.S                 |   4 +-
 arch/powerpc/mm/Makefile                     |   7 +
 arch/powerpc/mm/init_32.c                    |   3 +
 arch/powerpc/mm/kasan/Makefile               |   5 +
 arch/powerpc/mm/kasan/kasan_init_32.c        | 183 +++++++++++++++++++++
 arch/powerpc/mm/mem.c                        |   4 +
 arch/powerpc/mm/mmu_decl.h                   |   2 +
 arch/powerpc/mm/ppc_mmu_32.c                 |  36 +++--
 arch/powerpc/mm/ptdump/ptdump.c              |   8 +
 arch/powerpc/platforms/powermac/Makefile     |   6 +
 arch/powerpc/purgatory/Makefile              |   3 +
 arch/powerpc/xmon/Makefile                   |   1 +
 34 files changed, 697 insertions(+), 142 deletions(-)
 create mode 100644 arch/powerpc/include/asm/kasan.h
 create mode 100644 arch/powerpc/kernel/early_32.c
 create mode 100644 arch/powerpc/mm/kasan/Makefile
 create mode 100644 arch/powerpc/mm/kasan/kasan_init_32.c