Coverage for UFFDIO_REGISTER_MODE_RWP and UFFDIO_RWPROTECT:
rwp-async async mode — touch pages, verify permissions are
auto-restored without a message
rwp-sync sync mode — access blocks, handler resolves via
UFFDIO_RWPROTECT
rwp-pagemap PAGEMAP_SCAN reports still-cold pages via
inverted PAGE_IS_ACCESSED
rwp-mprotect RWP survives mprotect(PROT_NONE) ->
mprotect(PROT_READ|PROT_WRITE) round-trip
rwp-gup GUP walks through a protnone RWP PTE (pipe
write/read drives the GUP path)
rwp-async-toggle UFFDIO_SET_MODE flips between sync and async
without re-registering
rwp-close closing the uffd restores page permissions
rwp-fork RWP survives fork() with EVENT_FORK; child's
PTEs keep the uffd bit
rwp-fork-pin RWP survives fork() on an RO-longterm-pinned
anon page (forces copy_present_page()); child
read auto-resolves and clears the bit, proving
PAGE_NONE was in place
rwp-wp-exclusive register with MODE_WP|MODE_RWP returns -EINVAL
All tests run against anon, shmem, shmem-private, hugetlb, and
hugetlb-private memory, except rwp-fork-pin which is anon-only —
copy_present_page() is the private-anon pinned-exclusive fork path.
Snapshot the RWP additions into tools/include/uapi/linux/userfaultfd.h so
the selftest builds without requiring "make headers" first, matching the
mechanism established by commit 580ea358af ("selftests/mm: fix
additional build errors for selftests").
Link: https://lore.kernel.org/ak-Z9KO2mP9HMOPW@thinkstation
Signed-off-by: Kiryl Shutsemau <[email protected]>
Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: James Houghton <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: SeongJae Park <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
These build errors only occur if one fails to first run "make headers".
However, that is a non-obvious and instrusive requirement, and so there
was a discussion on how to get rid of it [1]. This uses that solution.
These two files were created by taking a snapshot of the generated header
files that are created via "make headers". These two files were copied
from ./usr/include/linux/ to ./tools/include/uapi/linux/ .
That fixes the selftests/mm build on today's Arch Linux (which required
the userfaultfd.h) and Ubuntu 23.04 (which additionally required memfd.h).
[1] https://lore.kernel.org/all/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: John Hubbard <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Muhammad Usama Anjum <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: Axel Rasmussen <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Kiryl Shutsemau (Meta)