Re: [PATCH] mm/mremap: enforce the driver's page size on resize and move

["Lorenzo Stoakes (ARM)" <ljs@kernel.org>]

On Sun, Nov 15, 2026 at 12:47:00AM +0800, shao.mingyin@zte.com.cn wrote:
> From: Shao Mingyin <shao.mingyin@zte.com.cn>
>
> mm/mremap: enforce the driver's page size on resize and move
>
> device-dax exposes its mapping granularity through vm_ops->pagesize()
> and requires both VMA boundaries to be aligned to it. mremap() checks
> may_split() when moving a subrange, but does not validate the new end of
> an in-place expansion or both boundaries of the destination VMA.
>
> An unaligned expansion or move can therefore succeed and leave a VMA
> that device-dax rejects at fault time with SIGBUS. Check the final
> new_addr and new_len before moving, and check vm_end + delta before
> expanding in place.
>
> Checking the actual boundaries preserves an expansion starting inside a
> VMA when its resulting end remains aligned. The move check also covers
> equal-length MREMAP_FIXED moves. Existing PAGE_SIZE mappings pass both
> checks, and the existing hugetlb restrictions remain in effect.
>
> Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn>

NAK obviously.

This patch is broken, wrong, and it's not even a bug.

Also, you are flooding the kernel with patches, 17 series across 7
subsystems over 23 hrs:

https://lore.kernel.org/all/?q=f%3Ashao.mingyin%40zte.com.cn

Please just go away. Nobody wants your AI slop.

--
Cheers, Lorenzo