[v1,0/2] mm: Clear uffd-wp PTE/PMD state on mremap()

Message

Ryan Roberts Jan. 7, 2025, 2:47 p.m. UTC

Hi All,

This series contains a fix for a warning emitted when a uffd-registered region,
which doesn't have UFFD_FEATURE_EVENT_REMAP, is mremap()ed. patch 1 describes
the problem and fixes it, and patch 2 adds a selftest to verify the fix.

Thanks to Mikołaj Lenczewski who originally created the patch, which I have
subsequently extended.

Applies on top of mm-unstable (f349e79bfbf3)

Thanks,
Ryan

Ryan Roberts (2):
  mm: Clear uffd-wp PTE/PMD state on mremap()
  selftests/mm: Introduce uffd-wp-mremap regression test

 include/linux/userfaultfd_k.h               |  12 +
 mm/huge_memory.c                            |  12 +
 mm/hugetlb.c                                |  14 +-
 mm/mremap.c                                 |  32 +-
 tools/testing/selftests/mm/.gitignore       |   1 +
 tools/testing/selftests/mm/Makefile         |   2 +
 tools/testing/selftests/mm/run_vmtests.sh   |   1 +
 tools/testing/selftests/mm/uffd-wp-mremap.c | 380 ++++++++++++++++++++
 8 files changed, 452 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/mm/uffd-wp-mremap.c

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2.43.0