Re: [PATCH v3 40/40] mm/vma: introduce and use vma[_flags]_can_gup()
From: "Zi Yan" <ziy@nvidia.com>
Date: 2026-10-01 15:23:31
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-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:
GUP cannot be used for VMAs which set VMA_IO_BIT - because memory-mapped I/O must not be accessed on the user's behalf - or VMA_PFNMAP_BIT - because PFN maps have no folios which the kernel is permitted to access. Rather than keeping these checks open-coded, abstract them to vma_flags_can_gup() and its VMA wrapper vma_can_gup(). A number of other places make the same check to decide whether a mapping can be populated or accessed as GUP would, so update those too. While here, drop a reference to 'special' and replace a use of the deprecated VMA flags API in vma_dump_size(). No functional change intended. Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> --- fs/coredump.c | 4 ++-- include/linux/mm.h | 29 +++++++++++++++++++++++++++++ mm/gup.c | 7 +++---- mm/hmm.c | 3 +-- mm/memory.c | 14 ++++++++------ mm/mempolicy.c | 3 ++- 6 files changed, 45 insertions(+), 15 deletions(-)
Makes sense. Reviewed-by: Zi Yan <ziy@nvidia.com> -- Best Regards, Yan, Zi