[PATCH v3 0/9] Various mm kselftests improvements/fixes

[Kevin Brodsky <kevin.brodsky@arm.com>]

Various improvements/fixes for the mm kselftests:

- Patch 1-3 extend support for more build configurations: out-of-tree
  $KDIR, cross-compilation, etc.

- Patch 4-7 fix issues related to faulting in pages, introducing a new
  helper for that purpose.

- Patch 8 fixes the value returned by pagemap_ioctl (PASS was always
  returned, which explains why the issue fixed in patch 6 went
  unnoticed).

- Patch 9 improves the exit code of pfnmap.

Net results:
- 1 test no longer fails (patch 7)
- 3 tests are no longer skipped (patch 4)
- More accurate return values for whole suites (patch 8, 9)
- Extra tests are more likely to be built (patch 1-3)

---
v2..v3:
- Patch 5: new patch [David Hildenbrand]
- Patch 6: make the helper take a number of pages + pagesize, rename to
  force_read_pages() [David]
- Patch 7: improved page count calculation (avoiding floating-point
  helper)
- Patch 7: added Fixes tag [David]
- Patch 9: open the file only once and save the fd [David]
- Collected R-b/A-b

v2: https://lore.kernel.org/all/20260107164842.3289559-1-kevin.brodsky@arm.com/

v1..v2:
- New patches: 1, 4, 5, 8

v1: https://lore.kernel.org/all/20251216142633.2401447-1-kevin.brodsky@arm.com/
---
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
---
Kevin Brodsky (9):
  selftests/mm: default KDIR to build directory
  selftests/mm: remove flaky header check
  selftests/mm: pass down full CC and CFLAGS to check_config.sh
  selftests/mm: fix usage of FORCE_READ() in cow tests
  selftests/mm: check that FORCE_READ() succeeded
  selftests/mm: introduce helper to read every page
  selftests/mm: fix faulting-in code in pagemap_ioctl test
  selftests/mm: fix exit code in pagemap_ioctl
  selftests/mm: report SKIP in pfnmap if a check fails

 tools/testing/selftests/mm/Makefile           |  8 +-
 tools/testing/selftests/mm/check_config.sh    |  3 +-
 tools/testing/selftests/mm/cow.c              | 43 +++++++--
 tools/testing/selftests/mm/hugetlb-madvise.c  |  9 +-
 tools/testing/selftests/mm/page_frag/Makefile |  2 +-
 tools/testing/selftests/mm/pagemap_ioctl.c    | 15 ++-
 tools/testing/selftests/mm/pfnmap.c           | 93 +++++++++++--------
 .../selftests/mm/split_huge_page_test.c       |  6 +-
 tools/testing/selftests/mm/vm_util.h          |  7 ++
 9 files changed, 109 insertions(+), 77 deletions(-)


base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7
-- 
2.51.2