Re: [PATCH v4 2/9] mm: add atomic VMA flags and set VM_MAYBE_GUARD as such
From: "David Hildenbrand (Red Hat)" <david@kernel.org>
Date: 2025-11-19 09:06:51
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linux-fsdevel, linux-kselftest, linux-mm, linux-trace-kernel, lkml
On 18.11.25 11:17, Lorenzo Stoakes wrote:
This patch adds the ability to atomically set VMA flags with only the mmap read/VMA read lock held. As this could be hugely problematic for VMA flags in general given that all other accesses are non-atomic and serialised by the mmap/VMA locks, we implement this with a strict allow-list - that is, only designated flags are allowed to do this. We make VM_MAYBE_GUARD one of these flags. Signed-off-by: Lorenzo Stoakes <redacted> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Vlastimil Babka <redacted> ---
IIUC all other flag modifications need a write lock, so this should just work. Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> -- Cheers David