Re: [PATCH v3 32/40] mm/uffd: use predicates for userfaultfd checks
flat view
From: "Zi Yan" <ziy@nvidia.com>
Date: 2026-09-30 02:02:50
Also in:
bpf, fuse-devel, kvm, kvm-riscv, kvmarm, linux-arch, linux-doc, linux-fbdev, linux-fsdevel, linux-mm, linux-perf-users, linux-rdma, linux-riscv, linux-s390, linux-scsi, linux-sound, linux-usb, linuxppc-dev, lkml, selinux, sparclinux
On Thu Sep 17, 2026 at 12:22 PM EDT, Lorenzo Stoakes (ARM) wrote:
Rather than directly checking VMA flags, use the newly introduced vma_is_kernel_owned() and vma_is_persistent() helpers in userfaultfd when assessing VMA suitability for userfaultfd and UFFDIO_MOVE. Update vma_move_compatible() so it's expressed in terms of VMA characteristics rather than arbitrary flags. Additionally, update the use of the deprecated VMA flag API when checking VMA_SHADOW_STACK_BIT. A VMA_IO_BIT check is no longer required but that is fine as a hard invariant has been established that only kernel-owned mappings may set VMA_IO_BIT so the check is now redundant. Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> --- mm/userfaultfd.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)
LGTM. Acked-by: Zi Yan <ziy@nvidia.com> -- Best Regards, Yan, Zi