lkml.org 
[lkml]   [2022]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -next 3/4] arm64: mm: add support for page table check
On Mon, Mar 21, 2022 at 02:15:36PM +0800, Tong Tiangen wrote:
> Considering all your suggestions, The final logic should be:
>
> +#define pte_user(pte) (!!(pte_val(pte) & PTE_USER))
>
> +#define pmd_user(pmd) pte_user(pmd_pte(pmd))
> +#define pmd_user_exec(pmd) pte_user_exec(pmd_pte(pmd))
>
> +#define pud_user(pud) pte_user(pud_pte(pud))
>
> +static inline bool pte_user_accessible_page(pte_t pte)
> +{
> + return pte_present(pte) && (pte_user(pte)|| pte_user_exec(pte));
> +}

This is fine.

> +static inline bool pmd_user_accessible_page(pmd_t pmd)
> +{
> + return pmd_present(pmd) && (pmd_user(pmd)|| pmd_user_exec(pmd));
> +}

That's fine as well assuming that the function is only called on the
set_pmd_at() path where we know that the pmd would be a block mapping
(huge page). I think that's the case from a quick look at the current
x86 implementation.

> +static inline bool pud_user_accessible_page(pud_t pud)
> +{
> + return pud_present(pud) && pud_user(pud);
> +}

Same here.

--
Catalin

\
 
 \ /
  Last update: 2022-03-21 17:42    [W:0.080 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site