[PATCH v6 0/6] KASAN for powerpc/32

[Christophe Leroy]

This serie adds KASAN support to powerpc/32

Tested on nohash/32 (8xx) and book3s/32 (mpc832x ie 603).
Boot tested on qemu mac99

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.

For book3s/32 we have to stick to KASAN_MINIMAL because Hash table
management is not active early enough at the time being.

Christophe Leroy (6):
  powerpc/mm: prepare kernel for KAsan on PPC32
  powerpc/32: Move early_init() in a separate file
  powerpc: prepare string/mem functions for KASAN
  powerpc/32: Add KASAN support
  kasan: allow architectures to provide an outline readiness check
  powerpc/32: enable CONFIG_KASAN for book3s hash

 arch/powerpc/Kconfig                          |   1 +
 arch/powerpc/Makefile                         |   9 ++
 arch/powerpc/include/asm/book3s/32/pgtable.h  |   2 +
 arch/powerpc/include/asm/highmem.h            |  10 +-
 arch/powerpc/include/asm/kasan.h              |  51 ++++++++
 arch/powerpc/include/asm/nohash/32/pgtable.h  |   2 +
 arch/powerpc/include/asm/setup.h              |   5 +
 arch/powerpc/include/asm/string.h             |  26 +++-
 arch/powerpc/kernel/Makefile                  |  11 +-
 arch/powerpc/kernel/asm-offsets.c             |   4 +
 arch/powerpc/kernel/cputable.c                |  13 +-
 arch/powerpc/kernel/early_32.c                |  36 ++++++
 arch/powerpc/kernel/head_32.S                 |   3 +
 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_check.sh        |  10 +-
 arch/powerpc/kernel/setup-common.c            |   2 +
 arch/powerpc/kernel/setup_32.c                |  28 -----
 arch/powerpc/lib/Makefile                     |  16 ++-
 arch/powerpc/lib/copy_32.S                    |  13 +-
 arch/powerpc/lib/mem_64.S                     |   8 +-
 arch/powerpc/lib/memcpy_64.S                  |   4 +-
 arch/powerpc/mm/Makefile                      |   1 +
 arch/powerpc/mm/kasan/Makefile                |   5 +
 arch/powerpc/mm/kasan/kasan_init_32.c         | 170 ++++++++++++++++++++++++++
 arch/powerpc/mm/mem.c                         |   4 +
 arch/powerpc/mm/ptdump/dump_linuxpagetables.c |   8 ++
 arch/powerpc/purgatory/Makefile               |   3 +
 arch/powerpc/xmon/Makefile                    |   1 +
 include/linux/kasan.h                         |   4 +
 mm/kasan/generic.c                            |   3 +
 33 files changed, 412 insertions(+), 53 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

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2.13.3