[PATCH v7 00/38] kmsan: Enable on s390

[Ilya Leoshkevich <iii@linux.ibm.com>]

v6: https://lore.kernel.org/lkml/20240621002616.40684-1-iii@linux.ibm.com/
v6 -> v7: Drop the ptdump patch.
          All patches are reviewed.

v5: https://lore.kernel.org/lkml/20240619154530.163232-1-iii@linux.ibm.com/
v5 -> v6: Include KMSAN vmalloc areas in page table dump.
          Fix doc comments; use KMSAN_WARN_ON (Alexander P.).
          Patches that need review:
          - [PATCH 16/39] kmsan: Expose KMSAN_WARN_ON()
          - [PATCH 32/39] s390/ptdump: Add KMSAN page markers

v4: https://lore.kernel.org/lkml/20240613153924.961511-1-iii@linux.ibm.com/
v4 -> v5: Fix the __memset() build issue.
          Change the attribute #defines to lowercase in order to match
          the existing code style.
          Fix the kmsan_virt_addr_valid() implementation to avoid
          recursion in debug builds, like it's done on x86_64 - dropped
          R-bs, please take another look.
          Add kmsan_disable_current()/kmsan_enable_current() doc;
          Fix the poisoned memchr_inv() value in a different way;
          Add the missing linux/instrumented.h #include;
          (Alexander P.).
          Patches that need review:
          - [PATCH 12/37] kmsan: Introduce memset_no_sanitize_memory()
          - [PATCH 13/37] kmsan: Support SLAB_POISON
          - [PATCH 17/37] mm: slub: Disable KMSAN when checking the padding bytes
          - [PATCH 36/37] s390/kmsan: Implement the architecture-specific functions

v3: https://lore.kernel.org/lkml/20231213233605.661251-1-iii@linux.ibm.com/
v3 -> v4: Rebase.
          Elaborate why ftrace_ops_list_func() change is needed on
          x64_64 (Steven).
          Add a comment to the DFLTCC patch (Alexander P.).
          Simplify diag224();
          Improve __arch_local_irq_attributes style;
          Use IS_ENABLED(CONFIG_KMSAN) for vmalloc area (Heiko).
          Align vmalloc area on _SEGMENT_SIZE (Alexander G.).

v2: https://lore.kernel.org/lkml/20231121220155.1217090-1-iii@linux.ibm.com/
v2 -> v3: Drop kmsan_memmove_metadata() and strlcpy() patches;
          Remove kmsan_get_metadata() stub;
          Move kmsan_enable_current() and kmsan_disable_current() to
          include/linux/kmsan.h, explain why a counter is needed;
          Drop the memset_no_sanitize_memory() patch;
          Use __memset() in the SLAB_POISON patch;
          Add kmsan-checks.h to the DFLTCC patch;
          Add recursion check to the arch_kmsan_get_meta_or_null()
          patch (Alexander P.).

          Fix inline + __no_kmsan_checks issues.
          New patch for s390/irqflags, that resolves a lockdep warning.
          New patch for s390/diag, that resolves a false positive when
          running on an LPAR.
          New patch for STCCTM, same as above.
          New patch for check_bytes_and_report() that resolves a false
          positive that occurs even on Intel.

v1: https://lore.kernel.org/lkml/20231115203401.2495875-1-iii@linux.ibm.com/
v1 -> v2: Add comments, sort #includes, introduce
          memset_no_sanitize_memory() and use it to avoid unpoisoning
          of redzones, change vmalloc alignment to _REGION3_SIZE, add
          R-bs (Alexander P.).

          Fix building
          [PATCH 28/33] s390/string: Add KMSAN support
          with FORTIFY_SOURCE.
          Reported-by: kernel test robot <lkp@intel.com>
          Closes: https://lore.kernel.org/oe-kbuild-all/202311170550.bSBo44ix-lkp@intel.com/

Hi,

This series provides the minimal support for Kernel Memory Sanitizer on
s390. Kernel Memory Sanitizer is clang-only instrumentation for finding
accesses to uninitialized memory. The clang support for s390 has already
been merged [1].

With this series, I can successfully boot s390 defconfig and
debug_defconfig with kmsan.panic=1. The tool found one real
s390-specific bug (fixed in master).

Best regards,
Ilya

[1] https://reviews.llvm.org/D148596

Ilya Leoshkevich (38):
  ftrace: Unpoison ftrace_regs in ftrace_ops_list_func()
  kmsan: Make the tests compatible with kmsan.panic=1
  kmsan: Disable KMSAN when DEFERRED_STRUCT_PAGE_INIT is enabled
  kmsan: Increase the maximum store size to 4096
  kmsan: Fix is_bad_asm_addr() on arches with overlapping address spaces
  kmsan: Fix kmsan_copy_to_user() on arches with overlapping address
    spaces
  kmsan: Remove a useless assignment from
    kmsan_vmap_pages_range_noflush()
  kmsan: Remove an x86-specific #include from kmsan.h
  kmsan: Expose kmsan_get_metadata()
  kmsan: Export panic_on_kmsan
  kmsan: Allow disabling KMSAN checks for the current task
  kmsan: Introduce memset_no_sanitize_memory()
  kmsan: Support SLAB_POISON
  kmsan: Use ALIGN_DOWN() in kmsan_get_metadata()
  kmsan: Do not round up pg_data_t size
  kmsan: Expose KMSAN_WARN_ON()
  mm: slub: Let KMSAN access metadata
  mm: slub: Disable KMSAN when checking the padding bytes
  mm: kfence: Disable KMSAN when checking the canary
  lib/zlib: Unpoison DFLTCC output buffers
  kmsan: Accept ranges starting with 0 on s390
  s390/boot: Turn off KMSAN
  s390: Use a larger stack for KMSAN
  s390/boot: Add the KMSAN runtime stub
  s390/checksum: Add a KMSAN check
  s390/cpacf: Unpoison the results of cpacf_trng()
  s390/cpumf: Unpoison STCCTM output buffer
  s390/diag: Unpoison diag224() output buffer
  s390/ftrace: Unpoison ftrace_regs in kprobe_ftrace_handler()
  s390/irqflags: Do not instrument arch_local_irq_*() with KMSAN
  s390/mm: Define KMSAN metadata for vmalloc and modules
  s390/string: Add KMSAN support
  s390/traps: Unpoison the kernel_stack_overflow()'s pt_regs
  s390/uaccess: Add KMSAN support to put_user() and get_user()
  s390/uaccess: Add the missing linux/instrumented.h #include
  s390/unwind: Disable KMSAN checks
  s390/kmsan: Implement the architecture-specific functions
  kmsan: Enable on s390

 Documentation/dev-tools/kmsan.rst   |  11 ++-
 arch/s390/Kconfig                   |   1 +
 arch/s390/Makefile                  |   2 +-
 arch/s390/boot/Makefile             |   3 +
 arch/s390/boot/kmsan.c              |   6 ++
 arch/s390/boot/startup.c            |   7 ++
 arch/s390/boot/string.c             |  16 ++++
 arch/s390/include/asm/checksum.h    |   2 +
 arch/s390/include/asm/cpacf.h       |   3 +
 arch/s390/include/asm/cpu_mf.h      |   6 ++
 arch/s390/include/asm/irqflags.h    |  17 ++++-
 arch/s390/include/asm/kmsan.h       |  59 +++++++++++++++
 arch/s390/include/asm/pgtable.h     |  12 +++
 arch/s390/include/asm/string.h      |  20 +++--
 arch/s390/include/asm/thread_info.h |   2 +-
 arch/s390/include/asm/uaccess.h     | 112 ++++++++++++++++++++--------
 arch/s390/kernel/diag.c             |  10 ++-
 arch/s390/kernel/ftrace.c           |   2 +
 arch/s390/kernel/traps.c            |   6 ++
 arch/s390/kernel/unwind_bc.c        |   4 +
 drivers/s390/char/sclp.c            |   2 +-
 include/linux/kmsan.h               |  76 +++++++++++++++++++
 include/linux/kmsan_types.h         |   2 +-
 kernel/trace/ftrace.c               |   1 +
 lib/zlib_dfltcc/dfltcc.h            |   1 +
 lib/zlib_dfltcc/dfltcc_util.h       |  28 +++++++
 mm/Kconfig                          |   1 +
 mm/kfence/core.c                    |  11 ++-
 mm/kmsan/core.c                     |   1 -
 mm/kmsan/hooks.c                    |  23 ++++--
 mm/kmsan/init.c                     |   7 +-
 mm/kmsan/instrumentation.c          |  11 +--
 mm/kmsan/kmsan.h                    |  33 ++------
 mm/kmsan/kmsan_test.c               |   5 ++
 mm/kmsan/report.c                   |   8 +-
 mm/kmsan/shadow.c                   |   9 +--
 mm/slub.c                           |  33 ++++++--
 tools/objtool/check.c               |   2 +
 38 files changed, 445 insertions(+), 110 deletions(-)
 create mode 100644 arch/s390/boot/kmsan.c
 create mode 100644 arch/s390/include/asm/kmsan.h

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2.45.1