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References: <20240215182756.3448972-1-lokeshgidra@google.com> <20240215182756.3448972-4-lokeshgidra@google.com>
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From: Suren Baghdasaryan <surenb@google.com>
Date: Thu, 15 Feb 2024 14:19:41 -0800
Message-ID: <CAJuCfpFe2spt082fdB99ow+pqGj+DKnep6cHxoVYRVYgyO9uhg@mail.gmail.com>
Subject: Re: [PATCH v7 3/4] mm: add vma_assert_locked() for !CONFIG_PER_VMA_LOCK
To: Lokesh Gidra <lokeshgidra@google.com>
Cc: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, 
	linux-mm@kvack.org, linux-kernel@vger.kernel.org, selinux@vger.kernel.org, 
	kernel-team@android.com, aarcange@redhat.com, peterx@redhat.com, 
	david@redhat.com, axelrasmussen@google.com, bgeffon@google.com, 
	willy@infradead.org, jannh@google.com, kaleshsingh@google.com, 
	ngeoffray@google.com, timmurray@google.com, rppt@kernel.org, 
	Liam.Howlett@oracle.com, ryan.roberts@arm.com
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On Thu, Feb 15, 2024 at 10:28=E2=80=AFAM Lokesh Gidra <lokeshgidra@google.c=
om> wrote:
>
> vma_assert_locked() is needed to replace mmap_assert_locked() once we
> start using per-vma locks in userfaultfd operations.
>
> In !CONFIG_PER_VMA_LOCK case when mm is locked, it implies that the
> given VMA is locked.

Yes, makes sense. With per-vma locks used in more places, this makes
replacing mmap_assert_locked() with vma_assert_locked() very
straight-forward.

>
> Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>

Reviewed-by: Suren Baghdasaryan <surenb@google.com>

> ---
>  include/linux/mm.h | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 3c85634b186c..5ece3ad34ef8 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -781,6 +781,11 @@ static inline struct vm_area_struct *lock_vma_under_=
rcu(struct mm_struct *mm,
>         return NULL;
>  }
>
> +static inline void vma_assert_locked(struct vm_area_struct *vma)
> +{
> +       mmap_assert_locked(vma->vm_mm);
> +}
> +
>  static inline void release_fault_lock(struct vm_fault *vmf)
>  {
>         mmap_read_unlock(vmf->vma->vm_mm);
> --
> 2.43.0.687.g38aa6559b0-goog
>