[PATCH v4 06/13] mm/debug_vm_pgtable/THP: Mark the pte entry huge before using set_pmd/pud_at

[Anshuman Khandual]

On 09/02/2020 05:12 PM, Aneesh Kumar K.V wrote:
> kernel expects entries to be marked huge before we use
> set_pmd_at()/set_pud_at().
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
> ---
>  mm/debug_vm_pgtable.c | 20 +++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 8704901f6bd8..9cafed39c236 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -155,7 +155,7 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
>  				      unsigned long pfn, unsigned long vaddr,
>  				      pgprot_t prot)
>  {
> -	pmd_t pmd = pfn_pmd(pfn, prot);
> +	pmd_t pmd;
>  
>  	if (!has_transparent_hugepage())
>  		return;
> @@ -164,19 +164,19 @@ static void __init pmd_advanced_tests(struct mm_struct *mm,
>  	/* Align the address wrt HPAGE_PMD_SIZE */
>  	vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE;
>  
> -	pmd = pfn_pmd(pfn, prot);
> +	pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
>  	set_pmd_at(mm, vaddr, pmdp, pmd);
>  	pmdp_set_wrprotect(mm, vaddr, pmdp);
>  	pmd = READ_ONCE(*pmdp);
>  	WARN_ON(pmd_write(pmd));
>  
> -	pmd = pfn_pmd(pfn, prot);
> +	pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
>  	set_pmd_at(mm, vaddr, pmdp, pmd);
>  	pmdp_huge_get_and_clear(mm, vaddr, pmdp);
>  	pmd = READ_ONCE(*pmdp);
>  	WARN_ON(!pmd_none(pmd));
>  
> -	pmd = pfn_pmd(pfn, prot);
> +	pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
>  	pmd = pmd_wrprotect(pmd);
>  	pmd = pmd_mkclean(pmd);
>  	set_pmd_at(mm, vaddr, pmdp, pmd);
> @@ -236,7 +236,7 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
>  
>  static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
>  {
> -	pmd_t pmd = pfn_pmd(pfn, prot);
> +	pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
>  
>  	if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
>  		return;
> @@ -276,7 +276,7 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
>  				      unsigned long pfn, unsigned long vaddr,
>  				      pgprot_t prot)
>  {
> -	pud_t pud = pfn_pud(pfn, prot);
> +	pud_t pud;
>  
>  	if (!has_transparent_hugepage())
>  		return;
> @@ -285,25 +285,27 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
>  	/* Align the address wrt HPAGE_PUD_SIZE */
>  	vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE;
>  
> +	pud = pud_mkhuge(pfn_pud(pfn, prot));
>  	set_pud_at(mm, vaddr, pudp, pud);
>  	pudp_set_wrprotect(mm, vaddr, pudp);
>  	pud = READ_ONCE(*pudp);
>  	WARN_ON(pud_write(pud));
>  
>  #ifndef __PAGETABLE_PMD_FOLDED
> -	pud = pfn_pud(pfn, prot);
> +	pud = pud_mkhuge(pfn_pud(pfn, prot));
>  	set_pud_at(mm, vaddr, pudp, pud);
>  	pudp_huge_get_and_clear(mm, vaddr, pudp);
>  	pud = READ_ONCE(*pudp);
>  	WARN_ON(!pud_none(pud));
>  
> -	pud = pfn_pud(pfn, prot);
> +	pud = pud_mkhuge(pfn_pud(pfn, prot));
>  	set_pud_at(mm, vaddr, pudp, pud);
>  	pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
>  	pud = READ_ONCE(*pudp);
>  	WARN_ON(!pud_none(pud));
>  #endif /* __PAGETABLE_PMD_FOLDED */
> -	pud = pfn_pud(pfn, prot);
> +
> +	pud = pud_mkhuge(pfn_pud(pfn, prot));
>  	pud = pud_wrprotect(pud);
>  	pud = pud_mkclean(pud);
>  	set_pud_at(mm, vaddr, pudp, pud);
> 

Reviewed-by: Anshuman Khandual <anshuman.khandual at arm.com>