Re: [PATCH v3 5/8] mm/x86: Make pud_leaf() only cares about PSE bit

David Hildenbrand
2024-07-31T12:22:39Z

On 15.07.24 21:21, Peter Xu wrote:
> An entry should be reported as PUD leaf even if it's PROT_NONE, in which
> case PRESENT bit isn't there. I hit bad pud without this when testing dax
> 1G on zapping a PROT_NONE PUD.
>

Subject s/cares/care/

> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: x86@kernel.org
> Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> arch/x86/include/asm/pgtable.h | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
> index 65b8e5bb902c..25fc6d809572 100644
> --- a/arch/x86/include/asm/pgtable.h
> +++ b/arch/x86/include/asm/pgtable.h
> @@ -1073,8 +1073,7 @@ static inline pmd_t *pud_pgtable(pud_t pud)
> #define pud_leaf pud_leaf
> static inline bool pud_leaf(pud_t pud)
> {
> - return (pud_val(pud) & (_PAGE_PSE | _PAGE_PRESENT)) ==
> - (_PAGE_PSE | _PAGE_PRESENT);
> + return pud_val(pud) & _PAGE_PSE;
> }
>
> static inline int pud_bad(pud_t pud)

Reviewed-by: David Hildenbrand <david@redhat.com>

--
Cheers,

David / dhildenb