These are not MMIO pages so VMA_IO_BIT is an inappropriate flag to set.
Instead, set them VMA_MIXEDMAP_BIT as they are kernel mappings and this is
the appropriate flag to set for those.
This provides the semantics required - no VMA merging is permitted, but
does not prevent GUP.
However this has no meaningful impact as these are refcounted and thus can
be GUPed.
A previous commit already prevented __mm_populate() from being invoked on
XOL areas, which VMA_IO_BIT was previously relied upon to do, so that is no
longer required.
Both VMAs set a VMA name, so always_dump_vma() returns true before
vma_dump_size() reaches its VMA_IO_BIT check, and thus there is no change
in core dump behaviour.
Change this for both the core xol_add_vma() function and the x86-specific
get_uprobe_trampoline() function.
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Sashiko has reviewed this patch and found no issues. It looks great!
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Sashiko AI review · https://sashiko.dev/#/patchset/20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org?part=22