linux-kernel - Re: [PATCH v2 1/6] mm: Move can_modify

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Message-ID: <8833a9f9-b85c-4a0b-b8c8-ec7f8468aa49@lucifer.local>
Date: Fri, 9 Aug 2024 10:57:25 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Pedro Falcato <pedro.falcato@...il.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
        "Liam R. Howlett" <Liam.Howlett@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, oliver.sang@...el.com,
        torvalds@...ux-foundation.org, jeffxu@...gle.com,
        Michael Ellerman <mpe@...erman.id.au>
Subject: Re: [PATCH v2 1/6] mm: Move can_modify_vma to mm/internal.h

On Wed, Aug 07, 2024 at 10:13:04PM GMT, Pedro Falcato wrote:
> Move can_modify_vma to internal.h so it can be inlined properly (with
> the intent to remove can_modify_mm callsites).

This is kind of petty, but it'd be nice to move this to mm/vma.h instead as it's
a vma-specific thing.

This also makes it testable under vma userland tests.

>
> Signed-off-by: Pedro Falcato <pedro.falcato@...il.com>
> ---
>  mm/internal.h | 24 ++++++++++++++++++++++++
>  mm/mseal.c    | 17 -----------------
>  2 files changed, 24 insertions(+), 17 deletions(-)
>
> diff --git a/mm/internal.h b/mm/internal.h
> index 52f7fc4e8ac..90f50f3c4cf 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -1353,6 +1353,24 @@ static inline int can_do_mseal(unsigned long flags)
>  	return 0;
>  }
>
> +static inline bool vma_is_sealed(struct vm_area_struct *vma)
> +{
> +	return (vma->vm_flags & VM_SEALED);
> +}
> +
> +/*
> + * check if a vma is sealed for modification.
> + * return true, if modification is allowed.
> + */
> +static inline bool can_modify_vma(struct vm_area_struct *vma)
> +{
> +	if (unlikely(vma_is_sealed(vma)))
> +		return false;
> +
> +	return true;
> +}
> +
> +
>  bool can_modify_mm(struct mm_struct *mm, unsigned long start,
>  		unsigned long end);
>  bool can_modify_mm_madv(struct mm_struct *mm, unsigned long start,
> @@ -1374,6 +1392,12 @@ static inline bool can_modify_mm_madv(struct mm_struct *mm, unsigned long start,
>  {
>  	return true;
>  }
> +
> +static inline bool can_modify_vma(struct vm_area_struct *vma)
> +{
> +	return true;
> +}
> +
>  #endif
>
>  #ifdef CONFIG_SHRINKER_DEBUG
> diff --git a/mm/mseal.c b/mm/mseal.c
> index bf783bba8ed..4591ae8d29c 100644
> --- a/mm/mseal.c
> +++ b/mm/mseal.c
> @@ -16,28 +16,11 @@
>  #include <linux/sched.h>
>  #include "internal.h"
>
> -static inline bool vma_is_sealed(struct vm_area_struct *vma)
> -{
> -	return (vma->vm_flags & VM_SEALED);
> -}
> -
>  static inline void set_vma_sealed(struct vm_area_struct *vma)
>  {
>  	vm_flags_set(vma, VM_SEALED);
>  }
>
> -/*
> - * check if a vma is sealed for modification.
> - * return true, if modification is allowed.
> - */
> -static bool can_modify_vma(struct vm_area_struct *vma)
> -{
> -	if (unlikely(vma_is_sealed(vma)))
> -		return false;
> -
> -	return true;
> -}
> -
>  static bool is_madv_discard(int behavior)
>  {
>  	return	behavior &
> --
> 2.46.0
>