Re: [PATCH] docs: proc: document ProtectionKey in smaps

From: David Hildenbrand (Arm)

Date: Tue Apr 07 2026 - 10:08:16 EST


On 4/7/26 14:51, Kevin Brodsky wrote:
> The ProtectionKey entry was added in v4.9; back then it was
> x86-specific, but it now lives in generic code and applies to all
> architectures supporting pkeys (currently x86, power, arm64).
>
> Time to document it: add a paragraph to proc.rst about the
> ProtectionKey entry.
>
> Reported-by: Yury Khrustalev <yury.khrustalev@xxxxxxx>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
> ---
> Cc: Jonathan Corbet <corbet@xxxxxxx>
> Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Lorenzo Stoakes <ljs@xxxxxxxxxx>
> Cc: Vlastimil Babka <vbabka@xxxxxxxxxx>
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> ---
> Documentation/filesystems/proc.rst | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
> index b0c0d1b45b99..d673cad7dbe4 100644
> --- a/Documentation/filesystems/proc.rst
> +++ b/Documentation/filesystems/proc.rst
> @@ -549,6 +549,10 @@ does not take into account swapped out page of underlying shmem objects.
> naturally aligned THP pages of any currently enabled size. 1 if true, 0
> otherwise.
>
> +If both the kernel and the system support protection keys (pkeys),
> +"ProtectionKey" indicates the memory protection key associated with the
> +virtual memory area.

Reviewed-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

--
Cheers,

David