Re: [PATCH] mm/vma: predicate vma_assert_stabilised() on CONFIG_DEBUG_VM

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

Andrew - could you update as below?

Thanks!

On Tue, Nov 10, 2026 at 03:10:40PM +0000, Lorenzo Stoakes (ARM) wrote:
[ ... ]
> diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
> index 9ccbbcbd7aca..9c3a9c6525c1 100644
> --- a/include/linux/mmap_lock.h
> +++ b/include/linux/mmap_lock.h
[ ... ]
>  /**
>   * vma_assert_stabilised() - assert that this VMA cannot be changed from
>   * underneath us either by having a VMA or mmap lock held.
> @@ -418,9 +423,18 @@ static inline void vma_assert_locked(const struct vm_area_struct *vma)
>   *
>   * With lockdep disabled we may sometimes race with other threads acquiring the
>   * mmap read lock simultaneous with our VMA read lock.
> + *
> + * Assert only if CONFIG_DEBUG_VM is set.
>   */
>  static inline void vma_assert_stabilised(const struct vm_area_struct *vma)
>  {
> +	if (!IS_ENABLED(CONFIG_DEBUG_VM))

Actually I think this should be:

	if (!IS_ENABLED(CONFIG_DEBUG_VM) || !IS_ENABLED(CONFIG_LOCKDEP))

So we keep the lockdep asserts going regardless if lockdep is enabled (you'd
expect most users to enable both together but still :)

> +		return;

--
Cheers, Lorenzo