Commit a0c9fd22 authored by Anshuman Khandual's avatar Anshuman Khandual Committed by Andrew Morton
Browse files

mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries 

This replaces all the existing READ_ONCE() based page table accesses with
respective pxdp_get() helpers. Although these helpers might also fallback
to READ_ONCE() as default, but they do provide an opportunity for various
platforms to override when required. This change is a step in direction to
replace all page table entry accesses with respective pxdp_get() helpers.

Link: https://lkml.kernel.org/r/20240910115746.514454-1-anshuman.khandual@arm.com


Signed-off-by: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 82ce8e2f

mm/debug_vm_pgtable.c

+25 −25
Original line number Diff line number Diff line
@@ -231,10 +231,10 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args) 
	set_pmd_at(args->mm, vaddr, args->pmdp, pmd);

	flush_dcache_page(page);

	pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(pmd_write(pmd));

	pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(!pmd_none(pmd));



	pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
@@ -245,10 +245,10 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args) 
	pmd = pmd_mkwrite(pmd, args->vma);

	pmd = pmd_mkdirty(pmd);

	pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));

	pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(!pmd_none(pmd));



	pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
@@ -256,7 +256,7 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args) 
	set_pmd_at(args->mm, vaddr, args->pmdp, pmd);

	flush_dcache_page(page);

	pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(pmd_young(pmd));



	/*  Clear the pte entries  */
@@ -357,12 +357,12 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) 
	set_pud_at(args->mm, vaddr, args->pudp, pud);

	flush_dcache_page(page);

	pudp_set_wrprotect(args->mm, vaddr, args->pudp);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(pud_write(pud));



#ifndef __PAGETABLE_PMD_FOLDED

	pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(!pud_none(pud));

#endif /* __PAGETABLE_PMD_FOLDED */

	pud = pfn_pud(args->pud_pfn, args->page_prot);
@@ -374,12 +374,12 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) 
	pud = pud_mkwrite(pud);

	pud = pud_mkdirty(pud);

	pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(!(pud_write(pud) && pud_dirty(pud)));



#ifndef __PAGETABLE_PMD_FOLDED

	pudp_huge_get_and_clear_full(args->vma, vaddr, args->pudp, 1);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(!pud_none(pud));

#endif /* __PAGETABLE_PMD_FOLDED */
@@ -389,7 +389,7 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) 
	set_pud_at(args->mm, vaddr, args->pudp, pud);

	flush_dcache_page(page);

	pudp_test_and_clear_young(args->vma, vaddr, args->pudp);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(pud_young(pud));



	pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
@@ -441,7 +441,7 @@ static void __init pmd_huge_tests(struct pgtable_debug_args *args) 
	WRITE_ONCE(*args->pmdp, __pmd(0));

	WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));

	WARN_ON(!pmd_clear_huge(args->pmdp));

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(!pmd_none(pmd));

}
@@ -461,7 +461,7 @@ static void __init pud_huge_tests(struct pgtable_debug_args *args) 
	WRITE_ONCE(*args->pudp, __pud(0));

	WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));

	WARN_ON(!pud_clear_huge(args->pudp));

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(!pud_none(pud));

}

#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
@@ -490,7 +490,7 @@ static void __init pgd_basic_tests(struct pgtable_debug_args *args) 
#ifndef __PAGETABLE_PUD_FOLDED

static void __init pud_clear_tests(struct pgtable_debug_args *args)

{

	pud_t pud = READ_ONCE(*args->pudp);

	pud_t pud = pudp_get(args->pudp);



	if (mm_pmd_folded(args->mm))

		return;
@@ -498,7 +498,7 @@ static void __init pud_clear_tests(struct pgtable_debug_args *args) 
	pr_debug("Validating PUD clear\n");

	WARN_ON(pud_none(pud));

	pud_clear(args->pudp);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(!pud_none(pud));

}
@@ -515,7 +515,7 @@ static void __init pud_populate_tests(struct pgtable_debug_args *args) 
	 * Hence this must not qualify as pud_bad().

	 */

	pud_populate(args->mm, args->pudp, args->start_pmdp);

	pud = READ_ONCE(*args->pudp);

	pud = pudp_get(args->pudp);

	WARN_ON(pud_bad(pud));

}

#else  /* !__PAGETABLE_PUD_FOLDED */
@@ -526,7 +526,7 @@ static void __init pud_populate_tests(struct pgtable_debug_args *args) { } 
#ifndef __PAGETABLE_P4D_FOLDED

static void __init p4d_clear_tests(struct pgtable_debug_args *args)

{

	p4d_t p4d = READ_ONCE(*args->p4dp);

	p4d_t p4d = p4dp_get(args->p4dp);



	if (mm_pud_folded(args->mm))

		return;
@@ -534,7 +534,7 @@ static void __init p4d_clear_tests(struct pgtable_debug_args *args) 
	pr_debug("Validating P4D clear\n");

	WARN_ON(p4d_none(p4d));

	p4d_clear(args->p4dp);

	p4d = READ_ONCE(*args->p4dp);

	p4d = p4dp_get(args->p4dp);

	WARN_ON(!p4d_none(p4d));

}
@@ -553,13 +553,13 @@ static void __init p4d_populate_tests(struct pgtable_debug_args *args) 
	pud_clear(args->pudp);

	p4d_clear(args->p4dp);

	p4d_populate(args->mm, args->p4dp, args->start_pudp);

	p4d = READ_ONCE(*args->p4dp);

	p4d = p4dp_get(args->p4dp);

	WARN_ON(p4d_bad(p4d));

}



static void __init pgd_clear_tests(struct pgtable_debug_args *args)

{

	pgd_t pgd = READ_ONCE(*(args->pgdp));

	pgd_t pgd = pgdp_get(args->pgdp);



	if (mm_p4d_folded(args->mm))

		return;
@@ -567,7 +567,7 @@ static void __init pgd_clear_tests(struct pgtable_debug_args *args) 
	pr_debug("Validating PGD clear\n");

	WARN_ON(pgd_none(pgd));

	pgd_clear(args->pgdp);

	pgd = READ_ONCE(*args->pgdp);

	pgd = pgdp_get(args->pgdp);

	WARN_ON(!pgd_none(pgd));

}
@@ -586,7 +586,7 @@ static void __init pgd_populate_tests(struct pgtable_debug_args *args) 
	p4d_clear(args->p4dp);

	pgd_clear(args->pgdp);

	pgd_populate(args->mm, args->pgdp, args->start_p4dp);

	pgd = READ_ONCE(*args->pgdp);

	pgd = pgdp_get(args->pgdp);

	WARN_ON(pgd_bad(pgd));

}

#else  /* !__PAGETABLE_P4D_FOLDED */
@@ -627,12 +627,12 @@ static void __init pte_clear_tests(struct pgtable_debug_args *args) 


static void __init pmd_clear_tests(struct pgtable_debug_args *args)

{

	pmd_t pmd = READ_ONCE(*args->pmdp);

	pmd_t pmd = pmdp_get(args->pmdp);



	pr_debug("Validating PMD clear\n");

	WARN_ON(pmd_none(pmd));

	pmd_clear(args->pmdp);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(!pmd_none(pmd));

}
@@ -646,7 +646,7 @@ static void __init pmd_populate_tests(struct pgtable_debug_args *args) 
	 * Hence this must not qualify as pmd_bad().

	 */

	pmd_populate(args->mm, args->pmdp, args->start_ptep);

	pmd = READ_ONCE(*args->pmdp);

	pmd = pmdp_get(args->pmdp);

	WARN_ON(pmd_bad(pmd));

}
@@ -1251,7 +1251,7 @@ static int __init init_args(struct pgtable_debug_args *args) 
		ret = -ENOMEM;

		goto error;

	}

	args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp));

	args->start_ptep = pmd_pgtable(pmdp_get(args->pmdp));

	WARN_ON(!args->start_ptep);



	init_fixed_pfns(args);