linux-kernel - Re: [PATCH 1/2] memfd: export memfd_{add,get}

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Message-ID: <aXYD4b46LcwSodjX@kernel.org>
Date: Sun, 25 Jan 2026 13:52:01 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Pratyush Yadav <pratyush@...nel.org>
Cc: Alexander Graf <graf@...zon.com>,
	Pasha Tatashin <pasha.tatashin@...een.com>,
	Hugh Dickins <hughd@...gle.com>,
	Baolin Wang <baolin.wang@...ux.alibaba.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Jason Gunthorpe <jgg@...dia.com>,
	Samiullah Khawaja <skhawaja@...gle.com>, kexec@...ts.infradead.org,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] memfd: export memfd_{add,get}_seals()

On Fri, Jan 23, 2026 at 10:58:50AM +0100, Pratyush Yadav wrote:
> From: "Pratyush Yadav (Google)" <pratyush@...nel.org>
> 
> Support for preserving file seals will be added to memfd preservation
> using the Live Update Orchestrator (LUO). Export
> memfd_{add,get}_seals)() so memfd_luo can use them to manipulate the
> seals.
> 
> Signed-off-by: Pratyush Yadav (Google) <pratyush@...nel.org>

Acked-by: Mike Rapoport (Microsoft) <rppt@...nel.org>

> ---
>  include/linux/memfd.h | 12 ++++++++++++
>  mm/memfd.c            |  4 ++--
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/memfd.h b/include/linux/memfd.h
> index c328a7b356d0..b4fda09dab9f 100644
> --- a/include/linux/memfd.h
> +++ b/include/linux/memfd.h
> @@ -18,6 +18,8 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx);
>   */
>  int memfd_check_seals_mmap(struct file *file, vm_flags_t *vm_flags_ptr);
>  struct file *memfd_alloc_file(const char *name, unsigned int flags);
> +int memfd_get_seals(struct file *file);
> +int memfd_add_seals(struct file *file, unsigned int seals);
>  #else
>  static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a)
>  {
> @@ -37,6 +39,16 @@ static inline struct file *memfd_alloc_file(const char *name, unsigned int flags
>  {
>  	return ERR_PTR(-EINVAL);
>  }
> +
> +static inline int memfd_get_seals(struct file *file)
> +{
> +	return -EINVAL;
> +}
> +
> +static inline int memfd_add_seals(struct file *file, unsigned int seals)
> +{
> +	return -EINVAL;
> +}
>  #endif
>  
>  #endif /* __LINUX_MEMFD_H */
> diff --git a/mm/memfd.c b/mm/memfd.c
> index f032c6052926..46c5508beea4 100644
> --- a/mm/memfd.c
> +++ b/mm/memfd.c
> @@ -228,7 +228,7 @@ static unsigned int *memfd_file_seals_ptr(struct file *file)
>  		     F_SEAL_WRITE | \
>  		     F_SEAL_FUTURE_WRITE)
>  
> -static int memfd_add_seals(struct file *file, unsigned int seals)
> +int memfd_add_seals(struct file *file, unsigned int seals)
>  {
>  	struct inode *inode = file_inode(file);
>  	unsigned int *file_seals;
> @@ -310,7 +310,7 @@ static int memfd_add_seals(struct file *file, unsigned int seals)
>  	return error;
>  }
>  
> -static int memfd_get_seals(struct file *file)
> +int memfd_get_seals(struct file *file)
>  {
>  	unsigned int *seals = memfd_file_seals_ptr(file);
>  
> -- 
> 2.52.0.457.g6b5491de43-goog
> 

-- 
Sincerely yours,
Mike.