[PATCH v5 00/37] kmsan: Enable on s390

Ilya Leoshkevich
2024-06-19T15:46:11Z

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 (37):
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
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 | 8 ++
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 | 46 ++++++++++++
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 | 9 +--
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, 410 insertions(+), 87 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