Two fixes and two cleanups for userfaultfd. Note that the third patch yields a small change in the ABI, but we seem to have concluded that that's acceptable in this case. --- Changes in v3: - Propagate tags. (David, Jason) - Move the uffd unregistration fixes patch before the VM_WARN_ON_ONCE() conversion patch, as per David. - Update comments and commit message of 2/4, as per David. - Update the commit message in 3/4 with more details about various conversions, as per David. - Convert two additional WARN_ON()s in 3/4, as per David. - Link to v2: https://lore.kernel.org/r/20250607-uffd-fixes-v2-0-339dafe9a2fe@xxxxxxxxxxxx Changes in v2: - Remove Pavel Emelyanov <xemul@xxxxxxxxxxxxx> from To: due to bouncing email. - Propagate tags. (David, Peter) - Add a patch converting userfaultfd BUG_ON()s to VM_WARN_ON_ONCE(). - Move the "different uffd" check in Patch 3 (prev. Patch 2) before the vma_can_userfault() check due to the wp_async bug, as per James. - Change the added BUG_ON() in Patch 3 to a VM_WARN_ON_ONCE, as per James and David. - Reorder the assertions in Patch 3 to simplify them and avoid the wp_async bug, as per James. - Update the Patch 3 commit message to include more details, as per Peter. - Link to v1: https://lore.kernel.org/r/20250603-uffd-fixes-v1-0-9c638c73f047@xxxxxxxxxxxx --- Tal Zussman (4): userfaultfd: correctly prevent registering VM_DROPPABLE regions userfaultfd: prevent unregistering VMAs through a different userfaultfd userfaultfd: remove (VM_)BUG_ON()s userfaultfd: remove UFFD_CLOEXEC, UFFD_NONBLOCK, and UFFD_FLAGS_SET fs/userfaultfd.c | 78 ++++++++++++++++++++++--------------------- include/linux/userfaultfd_k.h | 6 +--- mm/userfaultfd.c | 68 ++++++++++++++++++------------------- 3 files changed, 74 insertions(+), 78 deletions(-) --- base-commit: 546b1c9e93c2bb8cf5ed24e0be1c86bb089b3253 change-id: 20250531-uffd-fixes-142331b15e63 Best regards, -- Tal Zussman <tz2294@xxxxxxxxxxxx>
