Re: [PATCH v4 04/38] mm/vma: ensure mmap_prepare doesn't set actions on a mergeable vma

When a user requests an mmap_action be performed in mmap_prepare, this
involves populating the VMA range with data.

However, if the VMA is mergeable, it might then mistakenly be merged with
another VMA without having populated the range.

Every mmap action currently available sets VMA flags such that the VMA
cannot be merged.

However, to ensure that no future mmap action falls foul of this, assert
that this is the case upon mmap_prepare validation.

Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Gregory Price (Meta) <gourry@gourry.net>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261003-b4-mmap-prepare-vma-flag-sanify-v4-0-a1f052500fd7@kernel.org?part=4